Army Aviation Digest - Nov 1970

8/12/2019 Army Aviation Digest - Nov 1970

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UNITED ST TES ARMY AVIATION

Of ARMY AVIATION, ACSFOROF THE ARMY

MG Wi lliam J. Maddox Jr.U. S . ARMY AVIATION SCHOOL

MG Alien . M. Burdett Jr.COMDT, U. S. ARMY AVIATION SCHOOL

C O L Bill G . SmithIGEST STAFFLTC Robert E. luckenbill, ChiefRichard K. Tierney, EditorCPT Edward A. Bickel

lT Kenneth G. KitzmillerlT John H. Zwarensteyn

CW2 Kenneth L CavaraWilliam H. SmithLinda McGowanBrenda R. HarpBetty S. Wallace

ARTS SUPPORTHarry A. PickelDorothy L CrowleyAngela A. Akin

DIRECTOR, U. S . ARMY BOARD FOR AVIATIONACCIDENT RESEARCH

COL Eugene B. ConradPUBLICATIONS AND GRAPHICS DIV

Pierce L Wiggin, ChiefWilliam E. CarterJack DeloneyTed KontosCharles MobiusPatsy R. ThompsonMary W. Windham

NOVEMBER 197 VO LUM E 6 NUMBE

TACTICS THE OPINION OF THE SENIOR OFFICERMAJ Jim H. ClaryTHIRD MAN IN THE COCKPIT, Robert KurtzAEROMEDIC DANGEROUS INSIGNIAFORT EUSTIS, Clementine R BowmanPOT POURRIUSACSEWS: EMPHASIS ON AVIATION, SP4 Douglas KreutzTHE ROAD AHEAD FOR THE ARMY AVIATION WARRANTOFFICER, MAJ George CoutoumanosMAl NTENANCE MATTERS THE LOHFAC TACTICAL FIGHTER TEAM

CPT Richard T CrossCHAFING OF AIRCRAFT HOSES, MAJ Vincent G Ripoll and Donald R. Artis Jr.GRADUATION A LICENSE TO THINK MAJ Howard J. StilesCHARLIE AND DANNY'S WRITE-INPROFESSIONALISM A REAL LIFESAVER

CPT Kennard D Frazier4 WIRE TOLL, CW3 Leroy B Spivey and CW3 Morris L Marty AVIATION SAFETY OFFICER INDICATOR?

CW3 Kenneth W HillQUALITY AND SAFETY IN THE MAINTENANCE AREA

SFC Charles P JordanBROKEN WING AWARDEJECT EJECT LET'S GET OUT OF HERE

LTC Richard F TaylorTALES FROM THE TROJAN

44 USAASO SEZNEW ATC SIMULATOR Insid

The mission of the U. S. ARMY AVIATION DIGEST is to prov ide information of an operationalor functional nature concerning safety and aircraft accident prevent ion , train ing, mainten nc.,operations, research and development , aviat ion me d icine , and other related data.The DIGEST is an official Department of the Army periodica l published monthly under thesupervision of the Commandant , U. S. Army Aviat ion School. Views expressed here in are notnecessar ily those of Department of the Army or the U. S. Army Aviat ion School. Photos areU. S. Army unless otherw ise specified . Material may be reprinted prov ided cred it is g iven to theDIGEST and to the author, unless otherwise indicated .Articles, photos , and items of interest on Army av iat ion are inv ite d . Direct communication isauthorized to: Editor , U. S. Army Aviat ion Digest , Fort Rucker, Ala . 36360.Use of funds for print ing th is pu b lica t ion has been approved by Headquarters, DepartmQntof the Army, 3 November 1967 .Ac t ive Army un its rece ive dist ri but ion under the pinpoint distribution system as outlined inAR 310-1. Complete DA Form 12-4 and send directly to CO, AG Publications Center, 2800Eastern Boulevard, Balt imore , Md . 21220 . For any change in distributiol l requ irements, initiate arevised DA Form 12-4 .National Guard and Army Reserve units subm it requirements th rough their State adiutantsgeneral and U. S. Army Corps commanders respectively.For those not eligible for offic ial d istribution or who desire personal COPieS of the DIGEST,paid subscriptions, 4 .50 domestic and 5 .50 overseas, are available from the Superintendent ofDocuments, U. S. Government Printing Office, Washington, D. C. 20402.


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T CTICSThe Opin ion O f The Sen ior Off icer )

HAT ACTION should anarmed helicopter pilot takewhen confronted with enemy .50caliber antiaircraft fire? Most pilotswowdJprobably call for air strikesand / or artillery and then departthe area. Ninety-five percent of thetime this answer -would be C-0ff-eCtbut what about the other 5 percent? When artillery and air strikesare not available, how can an aviator handle this problem and accomplish his mission? At this pointan old adage, Tactics is the opinion of the senior officer present,becomes relevant.It would be useless to attempt todefine specific actions a pilotshould take when confronted withheavy antiaircraft fire. However, itmay be valid to become familiarwith how several Army aviatorssuccessfully developed and employed a scheme of fire and maneuver against .50 caliber antiaircraft fire.In 1968 in the IV Corps Tactical Zone (CTZ) of the Republicof Vietnam the Viet Cong (VC)launched a multibattalion assaultagainst a lightly defended Vietnamese district headquarters. The

assault began at 2200 hours andwas supported by mortar and recoilless rifle fire. The VC commander had emplaced several .50caliber, antiaircraft-mounted machine Jtuns in strategic positions too ~ n t r allied air support. At thistime artillery support was verylimited in IV Corps and immediateresponse to air strike requests was

NOVEMBER 1970

Major Jim H lary

not always possible. Thus, theVietnamese commanders reliedheavily upon U. S. Army helicopter gunships to provide aerialfire support and the success orfailure of the communist groundassault could, to a great degree,depend on their effectiveness.Terrain in the IV CTZ affordsassaulting ground troops onlylimited cover and concealmentduring attacks. Therefore, antiaircraft weapons were used to keepthe gunships at a range that wouldrender their fire support relativelyineffective.

The light fire team dispatchedto the embattled district was comprised of two AH-IG HueyCobrahelicopters which had only recentlybeen introduced into Vietnam. Thefire team quickly engaged theflashing mortars and recoillessrifles while the VC responded withintense antiaircraft fire. The fireteam leader requested artillery fireand a tactical air strike, but, artillery was out of range and Tac airwas not readily available. Meanwhile, the U. S. advisor at districtheadquarters radioed that the VCground attack had breached hisdefenses.The fire team leader ordered theteam to turn off all exterior lightsand instructed the team wingmanto decoy ground fire. When theantiaircraft gunners fired at the decoy who maintained sufficient altitude (3,000 feet) and distance totake evasive action, the fire teamleader made a low-level firing pass

at the assaulting enemy troops. Toretain the advantage of surprise,the VC were not attacked or decoyed consecutively from the samedirection. The attack angles werevaried by at least 90 degrees oneach firing pass.Shortly after the initial engagement, a third AH-l G joined thelight fire team and made a rotatingrearming and refueling schedulepossible. This enabled two of thethree gunships to provide constantoverhead cover to the districtheadquarters.The tactics outlined were employed throughout the night. Atapproximately 0500 the unsuccessful VC withdrew. Succeeding investigations proved the grazingfires of the attacking gunships werevery effective. They also revealedthat the VC had dug large pits inwhich to emplace their antiaircraftweapons. The walls of the pits hadbeen excavated to provide the gunners with overhead cover. Thisconstruction technique probablyaccounted for the failure of thegunships to completely neutralizethe antiaircraft fires. However, itis interesting to note that had

proximity fused or flechette rocketsbeen available, these positionsmight have been neutralized earlyin the battle.The employment of the fire teamin this situation is not meant to be

the school solution. The tacticsused that night were only theopinion of the senior officerpresent.1


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Third Man

Photos on these two pageby CW4 ill C Welton

Robert KurtzAir Traffic Control Specialistn The Cockpit U S Army Aeronaut ical Service Office

ST ATISTICS CAN always befound to support nearly anyviewpoint, but to bring your attention to some of the current problems in the U. S Army air trafficcontrol ATC) system here are acouple of eye openers: The Army operates more airfields worldwide than the U. SAir Force and three times thenumber of airfields/heliports in the2

Republic of Vietnam than do allthe other services, civil agenciesand free world forces combined. The Army controllers in Vietnam control more traffic than thatcontrolled by all the control towersin the entire Federal Aviation Ad-

This article does not necessarilyreflect the view of the Depart-ment of the Army

ministration FAA) Southern Rgion a seven-state area and thretimes the total CONUS militatraffic handled by the FAA.The point is the entire conceof aircraft employment, militaor civilian, revolves around an effcient means of control. Howevewithout some rapid improvemenin equipment, personnel and cocepts in the field of air traffic co

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trol this job will become progressively more difficult. Immediateaction on some of today s pressingproblems in this area could forestall, if not eliminate, future complications which are bound tocome. Here are some of the thingswith which you as Army aviationpersonnel should be concerned.Whether you are a mechanic in theStates or an aviation commanderin Vietnam, you are affected by airtraffic control in some way.

he rmy ControllerThe majority of the Anny air traffic controllers have undergoneschooling conducted by the AirForce, are subject to Army andFAA rules and regulations, andusually find themselves working ina foreign country under International Civil Aviation Organiza-

tion ICAO) rules which are supplemented by local allied agreements and tactical conditions. Withthe exception of the Air Forcetraining, this statement could fitthe Army aviator. Incidentally,that one exception was eliminatedlast October when the air trafficcontroller s school at Ft. Rucker,Ala. , was activated with a uniquecurriculum designed for the controltower, ground control and approach controller. Academic training alone does not produce an airtraffic controller who is qualifiedto control traffic. An additionalperiod of 2 to 6 months on-the-jobtraining is required in order toyield a productive individual.

TC roceduresOne of the restrictions whichthe ATC system has to face is the

existing concept of air traffic operation contained in the U. S ArmyAir Tr affic Operation Manual FM1-60. This concept is not entirelyaligned with the standards and procedures used by the FAA, USAFor host countries. The fact thatpractically all nations have subscribed to the ICAO air trafficrules and procedures must be considered for they will influence to adegree the ATC system used in allwars.Since the Air Force provides airtransport support, the standardsused by the Anny must be acceptable to Air Force commandersor be outlined in a Joint Tactical Air Traffic Control ManualJTATCM). The JTATCM exists

as only a figment of the author simagina tion.


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Third Man In The CockpitThe only standards for ATCoperations are contained in FAATerminal Air Traffic Control Manual 7110.8 (TM 11-2557-29) and

ICAO Annexe . Army Air TrafficOperations (FM 1-60) containsthe following statement: Armyaircraft operations below the coordination altitude will be controlled in accordance with ATCprocedures established by the Armycomponent commander, withoutnecessity for coordination with theATC facilities of other services."You might ask, "Well, what iswrong with that?" First, there isno air traffic control system whichis an entity. The standards andprocedures must interlace withadjacent areas and certain terminology must be used in orderthat maximum understanding isachieved. The use of the phrase"coordination altitude" has nomeaning in the air traffic field outside the Army. Let us join the restof the world and use "delegatedairspace" which includes both vertical and lateral limits.Delegated airspace is not necessarily controlled airspace. The responsible agency may designate,after coordination, certain segments as control airspace whereagreed-upon separation will beprovided. The remaining airspacewould be treated as "elsewherearea."

f we want acceptance by otheragencies, standard procedures mustbe applied between Army aircraftand other aircraft within controlledairspace. Reduction of standardsmay be realized if they are coordinated with and approved by theagency operating these other aircraft. Primarily this approval mustbe obtained from the Air Force,Navy and allied countries which,in a tactical environment, is timeconsuming and extremely difficultto accomplish. The proposed

JTATCM would outline certainapproved reductions of standardsbased on the tactical situation.Next, the tactical theater is notthe place to write, coordinate andpublish ATC procedures. That'sreally getting behind the powercurve since the Air Force mighthave already established an ATCsystem before the Army aviationrequirements are even defined, i.e. ,Korea, Vietnam, Thailand. Wherewill the Army find the expertise towrite these procedures? To myknowledge there is not one qualified air traffic controller in theentire officer ranks and no way toidentify those officers who haveATC experience at the commandand staff level.

ducationOfficers at the decision-makinglevel must be knowledgeable in the

ATC field. This can be accomplished by establishing a course ofinstruction which will produce anATC qualified officer with an identifying military occupational specialty (MOS). Some thought andrecognition has been given thisproblem by HQ CONARC and anofficer ATC school at Ft. Rucker,Ala. has just graduated their thirdclass of Army-trained ATC aviators; however, no ystem to maintain identity of these individualshas been programed.The U. S Army Aviation Schoolat Ft. Rucker pointed out this requirement early in 1967. TheArmy also requires a warrant officer career progression program

which would be available to qualified controllers who have workedbehind the mike. Additionally, allofficer branch and career coursesmust contain course material pertaining to their branch as it relatesto supporting the air traffic requirements.That is, Signal Branch shouldbe instructed on communication

requirements; Engineer Branshould understand control towand N A V AIDs siteing and costruction criteria; and all officshould understand the vital rothat ATC plays in providing logistic support. Wouldn't it wonderful if we had one carecourse specifically designed for tArmy aviatorThese officers should know ththere are regulations and manuapertaining to the Army ATC sytem written specifically for thguidance, e.g., AR 95-37, A95-9, TM 11-2557-25, TM 12557-26, TM 11-2557-28, T11-2557-29, TM 95-200, TB 95-Army Subject Schedule 1-4.

What is our problem? TArmy lacks ATC officers knowedgeable at the grass-roots levand jointly approved doctrineleft to field commanders to hassover on an individual basis.

Lessons LearnedThe real world" Army ATsystem equipment with some minmodifications is based on thesults of Air Assault II conductin 1964. This so-called real woris in reality a paper world" whicloses its eyes to existing requirments and proven procedures usin Vietnam. From the highelevels the word is regroup undreal world planning. The end rsult at the pencil-shoving levelthat Vietnam proves nothing.Leave Vietnam out of it is rpeatedly enjoined at conferencconcerned with ATC matters. Heeven war protesters admit we haa tactical situation in VietnamAre not the lessons learned the

worth consideration in defining tmodern day Army worldwiATC responsibilities? f aircraare to be retained organically the Army, the Army must proviATC services as it has providmaintenance support. What shoube said is, "How was it done Vietnam and what changes are rquired in order to adapt these le4 U. S ARMY AVIATION DIGES


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sons learned to various combatenvironments?It probably cannot be said that

ll officers directly involved inATC support in RVN would backthis statement, but it probably hasthe wholehearted approval of themajority. In fact , a few of thesecombat-proven veterans even become a bit emotional over thesubject. ManagementThe air traffic control towerequipment for one semifixed installation in a combat area costs inexcess of $200,000 and approximately $250,000 for a CONUS in-stallation. These figures do notinclude airfield lighting, nondirectional radio beacons, radar orVHF omnidirectional ranges. Now

NOVEMBER 1970

Above: United States rmy airtraffic controller plots the flight ofan aircraft passing through his controlsector over Germany Below: An FAAoperated air traffic control center

with this amount of money involved for equipment, which ismore or less a permanent inventoryitem, the Army has, of course,looked ahead and supplied qualifiedmaintenance and support personnel, right?Wrong. The MOS' of personnelassigned to maintain the groundTC equipment are those whichwere developed to support aircraftelectronics. An TC equipmentrepairman MOS course should beimplemented which would includesuch items s intercom system,barometer calibrations, wiring configurations, internal and externalwire plant installation, N V IDmonitor and alarm systems, switchpanels, facility lighting, environmental controls, etc.

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Third Man n The ockpit

- ... . /

As long as we are talking aboutequipment the air-ground radiosused in our tactical mobile facilities should be addressed. Theseradios were designed for use aboardaircraft and do not have an acceptable level of reliability when usedunder the continuous duty cycleof an ATC facility. This andall other equipment shortcomingsmentioned in this article werepointed out in a Tactical Air Traffic Control Equipment Study(TATCES) completed by the U.S.Army Aeronautical Service Officein October 1968 which, by theway, created no whitecap wavesof reaction.Although the Army has willingly accepted the responsibility ofcontrolling airspace over land combat forces , the planners are stilltrapped by outdated thinking anduncoordinated planning on whatequipment, personnel and organization will accomplish the task.

The system envisioned for theaviation company (ATC) and PM1-60 has a saturation point farbelow that of a radar environment.Radar isn't the final answer, butwhat is? Radar is here and presumably will continue to be the primary ATC tool for many, manyyears to come. Are we on board?No Outside of a couple ofCONUS installations there is nosurveillance radar in the ArmyATC system. Dont look down onsome of the small so -called underdeveloped nations; they are moreadvanced in manual control procedures and not far behind theArmy on terminal radar control(TRACON) facilities. Both Vietnam and Thailand will own andoperate approach control surveillance radars in 1970. The Army

This mobile control tower t CampEvans RVN, provided ir tr fficservice for over 25,000 ircr ftduring 1 month s operation

has no program to obtain this typradar for tactical use, irrespectivof stated field requirements.The AN / TPS-54 is a lightweighradar which, with modificationwould appear to satisfy the approach control requirement initially identified by Vietnam in 1966A GCA type radar (AN TPN-18 is used to provide service at thterminal radar control facilitieoperated by the Army in RVNAlthough the TPN-18 is usable, has several inherent disadvantagewhen used in a surveillance modfor a TRACON. These are: The high frequency of aX-band radar displays practicallall precipitation areas which, iturn, block out aircraft targetwhich would normally appear othe scope. Range is limited to a maximum of 40 nautical miles. A system to display fixesrunway centerlines and other datis not incorporated. A dome to cover the antenntransmitter is required in order tperform maintenance during certain weather conditions. Workinwith extremely high voltages during periods of precipitation is noconducive to career progressiofor the radar technician. A domwill also provide environmentacontrol which will increase reliability of the equipment. Backup transmitter and receiver are not installed. Consoles are large and heavfor today's mobility requirements Ground return is not elimnated since moving target indicato(MTI) circuits are not used.After the fact procurementthe standard for ATC equipmenand then only in a piecemeal fashion. Since Army airfield operationvary from LZ to high densitinstrumented airfields, several typeof control tower equipment musbe available. A man-portable, onposition tower is required at LZand low density tactical airfield

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The use of a two-position tower isrequired where an instrument capability exists or when traffic density dictates.A three position, four-man control tower should be available atinstrumented high density airfields.

Not one of the above requirementshas an Army Type A classification. Figure 1 depicts a remotedone-man control tower which willprovide two operating positions.Figure 2 shows the use of a oneman tower at a location requiringthree positions of operation (otherequipment has recently been installed) .

The requirements were outlinedover 1 year ago. How long willthis situation be prolonged beforeunderstanding is created in theaviation ranks.I am reasonably sure a pictureis beginning to emerge. Besides thecontrol tower, TRACON and GCAunits, other equipment must eobtained-power units, NDBs,T ACANs, VORs, remote arealanding systems (RALS) andmany more. These units form afamily of equipment which may beused separately or in combination,depending on the operational requirement.

In order to eliminate excessiveTOE authorizations; establish priorities within available assets;manage expensive and difficult toprocure items; monitor overallequipment and personnel performances; establish new requirementsbased on field experience; anddevelop a functional ATC communications system, a single manager is required within each fieldArmy. This manager would attachindividual ATC facilities to combatelements, as required. As his mostimportant tool the manager wouldhave a service evaluation sectionwhose duties would encompassevaluating controller techniques,procedures, phraseology, compliance with regulations, technicalevaluation of equipment and flightNOVEMBER 1970

inspection of instrument approaches.The service evaluation teamswould recommend the award orwithdrawal of controller facilityratings and detect flaws or deficiencies in the air traffic control

system. It is the only method bywhich the ATC system can beproperly evaluated. Regardless ofthe type war involved, this conceptis the proven and most reliablemethod to employ. t has workedin Vietnam; it would have done thejob in Korea or World War IIwhile, in retrospect, TOE 207E (G)hasn't satisfied a single tacticaloperation.Some of you combat veteransmight feel the Army flight following system in Vietnam had a combat support mission. The 165thA viation Group researched theirrecords and could find no exampleduring a period of 1 year wherethe VFR flight following systemwas instrumental in saving adowned aviator. No control authority rests with, nor can controlinstructions be issued by, the flightfollowing facilities. But because ofconcept they have been maintainedat some considerable expense inresources. Approximately 90 airtraffic controllers are used in theArmy flight following network inRVN.

Past Present and u ~ u r eWe in the Army can take solacein the fact that we are not alonewith our ATC problems. The Air

Force has problems obtaining center trained controllers for their airtraffic regulatory centers in Vietnam and Thailand. They are alsohard pressed to maintain theirpipeline of qualified controllers fortheir radar approach control centers (RAPCONs). In some casestheir equipment does not fill thebill but they do have an energeticprogram under way to overcomethis shortcoming.

The AN/TPN-19 is an Air Forcesponsored terminal radar facility-

surveillance and GCA which shouldshow up in the field around December 1972. A new mobile control tower (TSW-7) which may beused at high density airfields isundergoing testing at Eglin AFB,Fla. What is the Army planning inthese two areas?In 1964 a small development requirement was revised which included two types of control towersand a GCA radar facility. Anotherrevision was approved during May969. This piece of paper has beenfloating like a log on a becalmedsea and has not produced a singlepiece of hardware for use in thefield.

f the Army is to continue building airfields some investment andreorganization is imperative in theATC area. A centralized management of equipment and personnelassets must be implemented. Aqualitative materiel requirementfor a f mily of Army air trafficcontrol equipment, as recommended by the T ATCES, shouldbe developed.

FM 1-60 and TOEs should berevised to conform to modern daytechniques and state-of-the-artequipment with procedures agreedupon between the services and contained in a JTATCM.

CONUS ATC facilities must beoperated by Army personnel toprovide a training base in time ofwar and a nucleus of qualifiedpersonnel in times of peace. ttakes 1 to 2 years to train a qualified controller from the time heenters the service and our reenlistment rate is less than 5 percent.This won't hack the program. TheArmy ATC organization, personnel and equipment is in a dire stateof affairs and without some assistance from you Joe's in the field wewill continue to run into that oldadage from my great grandfatherwho said, He who fails to lookahead must be riding backwardson a jackass. Gentlemen, can'twe find a home for a bantling?

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o the aircrewmen: The protective clothing and equipmentworn by air crewmen is usuallyhighly regarded by even the mostdaredevil and carefree among us.However, we frequently take forgranted the safety of some minoradornments of our uniform. Recently, a Department of the Armymessage regarding subdued insignia provided for wear of a varietyof metal pin-on insignia for officerand enlisted personnel. The intentof this directive was most certainlyto enable frequent changes of insignia while reducing the expenseusually associated with tailoring.However, in the aviation environment such insignia could inadvertently act as discomforting or eveninjury contributing or producinginstruments.These sharp and irregularlyshaped metallic insignia could potentially interfere with comfortableflight or contribute to injury in thefollowing ways:8

D NGEROUS

Complicate or contribute toinjury sustained as a result of crashforces. For instance, the head andneck could flex forward and to theside, causing the lower face tocatch and scrape along the insignia. In another instance, a bluntpart of the aircraft could strike anindividual in the area of the insignia, causing the sharp insignia toinflict a wound more serious thanwas possible by the blunt objectalone. Such a wound in a vitalarea, such as the front of the neckabove the collar, could prove to befatal rather than simply minor. Result in injury during hastyegress from an aircraft. This typeof injury could occur under twoconditions. First, during ejectionor bailout from a disabled aircraft.Due to the effects of wind velocitywindblast), such insignia could bedriven against the flesh with increased force resulting in minorinjuries. However, during deployment and inflation of a parachute

harp metal insignia can caU einjuries in crash

canopy, the risers could catch thinsignia and inflict even more serous injury. The second manner ointerfering with safe egress mighbe as a result of catching on otheequipment within or a part of thaircraft. This could inflict injurprimarily or could delay egress under less than desirable condition Produce unnecessary discomfort and nuisance under otheequipment. A number of examplecould be cited here . . . the pressure of overriding shoulder hanesses, flak and protective vestsurvival vests, etc. Certainly minor condition, but in already uncomfortable and cramped cockpitevery little bit counts. Act as a heat sink. This lacondition is less likely to be problem but is, nevertheless, possble. During a flash fire such an itemwould conduct heat readily anmight produce mild injury, eithedirectly or indirectly. f nothinelse it will heat up under the ray

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INSIGNI

Provided by the Society oj U S.rmy Flight Surgeons

of the sun; but alas, what is onemore calorie of heat in the HueyCobra?The U S Army Board for Aviation Accident Research has accumulated over the years a few casesin which metal insignia have complicated or contributed to minorinjuries of the neck and face. Thus,this discussion is more than academic. However, prior to July1970 there was no mandatory requirement for the use of metalsubdued insignia on fatigue (andwe assume flight) clothing. Thisincreases the number of persons atrisk for such injury or complication. Since there are no fatal caseson record, it is difficult to criticizeor indict the wear of metal insignia.However, for safety s sake it mightbe prudent to limit the use of metalinsigina by air crew members. Per-haps the optional use of cloth in-signia by enlisted, as well as officer,flying personnel would satisfy allrequirements.NOVEMBER 1970

Nevertheless, any account of injury or difficulty arising from theuse of metal insignia needs to bedocumented. f you know of casesin which metal insignia contributedto injury during air crew duties,particularly if the injuries wereserious or fatal, report these tothe Editor, u. s. ARMY AVIATIONDIGEST Ft. Rucker, Ala. 36360.

o the flight surgeon: Most cer-tainly the determination of injury causation should be at theforefront of every flight surgeon sanalysis of an aircraft accident.Sometimes injury can be inflictedin subtle and unusual ways. Thepreceding discussion is a fittingexample. Often other items ofequipment are at fault. A poorlydesigned or constructed kneeboardduring crash force deceleration becomes a flurry of relatively highvelocity missiles, inflcting untoldinjury. Improperly stored or unnecessarily carried equipment becomes a cascading avalanche, re-

suIting in battered flesh.Thus, the flight surgeon s role inidentifying these hazards is vital.Certainly the investigation of anaircraft accident lends itself tomore than just an unpleasant, tiresome journey into the wilds or anunforeseen TDY. But you need notawait that fateful day. Join thesafety officer in his endeavors.When you note potential safetyhazards on the flight line or inflight, have them corrected iinmediately. Don t wait for the weightof statistical evidence. Some thingscan be taken on faith alone (or atleast on educated guesses). Nevertheless, our future decisions mustbe based on data eventually, sojoin your fellow air crewmen andsubmit al1Y accounts to the editor.Because of your diligence in reporting or preventing such minorinfractions of safety, you may beunknowlingly, even unwittingly,saving hundreds of tiny episodes ofsuffering even lives.


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ORT USTIS

MAYDA Yl MAYDAYl Thisis Red Dog Four-Six, losing transmission oil pressure,three-zero west of Qui Nhon.This message was picked up bya company operations officer andrelayed to the maintenance officersupporting a combat assault helicopter company in the Republic ofVietnam. t was a situation inwhich the maintenance officercould use the training he receivedat the U. S Army TransportationSchool, Ft. Eustis, Va., when heattended the Aircraft MaintenanceOfficer Course.The 13-week Aircraft Maintenance Officer Course is taught at

the Aviation Maintenance Training Department under the directionof Colonel Garrison J. Boyle III.Ft. Eustis is the only Army posttraining aviation maintenance officers.The course which began in June1954 teaches the maintenance officer to be a manager. The studentlearns the management tools usedto plan, organize, direct and control aviation maintenance activities.Students are taught in a modelshop laboratory which is set upsimilar to a maintenance shop inthe field. They learn to set up ashop which will meet the needs ofa particular unit. Stations are set

up for engine repair, power trainsystem repair and for other basiccomponent repairs needed in aparticular unit.10

Clementine R owman

Awareness of resources is emphasized during the course. One ofthe most important resources ispersonnel. Each station the studentsets up for specific repairs willhave a trained noncommissionedofficer in charge with the requiredenlisted men who have been trainedin the same military occupationalspecjalty MOS).Students are taught inspectiontechniques and the repair and servicing requirements of both fixedand rotary wing aircraft. Theylearn to evaluate damage, diagnosemalfunctions of the aircraft systems and their components, andprescribe the necessary repair procedures. Also, they are trained inaircraft recovery and evacuation.Thus, the maintenance officer istaught to be responsible for alltypes of maintenance on all typesof aircraft under his control or inhis shop.The first phase of the courseends with a 3-day period of actualmaintenance test flights. Specificmalfunctions are fed into the aircraft and the student must fly inthese aircraft to detect the trouble.These test flights give him the experience he will need in the fieldand the ability to predict the actions he must take to correct themalfunction.In this manner he gains a broadand diversified knowledge in allphases of aviation maintenance.The Aircraft Maintenance OfficerCourse is open to commissioned

and warrant officers of the ArmOfficers from the Navy, MariCorps, Air Force and allied ntions also are eligible to attend.After the first 13 weeks of traiing in the Aircraft MaintenanOfficer Course (Phase I) there afour additional phases open to thstudents in the form of maintnance test pilot courses.Beginning in mid-1966 the maitenance test pilot courses weplanned to give a common senapproach to the problems of maintenance officers in the field. Thewere designed to improve aircrareliability, increase safety anavailability, and cut maintenanccosts by early detection and rpairs. Each of the four phaseteaches the same techniques odifferent aircraft.The courses make qualifiemaintenance officers experts onparticular aircraft. Phase II teachethe UH-1 Huey and the AH-1HueyCobra; Phase II I, the CH-4Chinook; and Phase IV, the OV-Mohawk.Every aspect of troubleshootinis stressed in the courses. Malfunctions are fed into the aircraft. Foexample, the brakes which controthe rear wheels on the Chinoocan be disconnected. During thfirst check on the ground this trouble would not show up, but at later check in the test flight thstudent pilot has to lift the fronwheels off the ground and then hwould notice his rear brakes wer

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This is the last in a series of three- articles on aviation maintenancetraining at Ft. Eustis Va The first appeared in the September issueof the AVIATION DIGEST and the second in the October issue. This articleoutlines the scope of instruction as given in the Aircraft Mainte-nance Officer Course U S Army Transportation School Ft. Eustis Va

not working and would have t odetermine the reason why. Alsocertain gauges which measure temperature and pressure can be interchanged within a system to givemisleading or unreliable readingsor a bad gauge could be installed.There are 10 or more malfunctionswhich may be fed into the smalleraircraft and at least 30 into theChinook.The students are graded on howwell they find the discrepanciesrecognize the problems and prescribe the maintenance to correctthem. Classes are small rangingfrom four-to-six students. Duringthe morning students discuss a particular type of problem; in theafternoon they are in flight to diagnose the problem.t the end of the course the students are given a practical gradedflight which combines 10 or 12different types of problems. Thereare more than 100 problems whichmay be fed into these aircraft butthe course provides a procedurefor conducting test flights whichenables the pilot to diagnose problems and prescribe the appropriatecorrective action from the cockpitthereby saving many hours ofmaintenance downtime.Emergency maintenance situations can occur n any area of theworld where aviation units areoperating. But thanks to the training received at Ft. Eustis an Aircraft Maintenance Officer Coursegraduate can handle the problems.

NOVEMBER 1970

Above instruction is being given officer students inairframe repair. Below officer students attending theAircraft Maintenance Officer Course receive instruction


14/68

DistraughtThen

RE D

captain Lee W Jurney(left) of the AirspaceDivision of the Directorate of Plans,Training, Security at Ft. Rucker,Ala., and Eldon H. Olson, vicepresident and general manager ofHoneywell Aerospace Division,Minneapolis, Minn., inspect thefirst collision avoidance system being used by the military. It is beinginstalled on 222 helicopters at theU. S Army A y,iation School undera contract to Honeywell's Aerospace Division. The device gives apilot warning of possible collisionsituations with a pulsed tone in hisheadset and a flashing light on theinstrument panel.

new dimension was addedto the testing of Army aircraft recently when Brigadier General John P. Traylor, deputy commander of the U. S Army Aviation Systems Command (AVSCOM), St. Louis, Mo. , snipped awide white ribbon dedicating anadvanced computer system at theU. S Army Aviation Systems TestActivity (USAASTA) at EdwardsAir Force Base, Calif.The ribbon-cutting ceremoniesofficially inaugurated an AdvancedInstrumentation and Data AnalysisSystem (AIDAS). The new computer complex is to be used by the

USAAST A in conducting engineering flight tests of Army aircraft.The new system should make itpossible to drastically reduce theamount of time required in thefinal preparation of the test reportand to improve the accuracy ofthe data obtained in flight tests.The AIDAS is manufactured bythe Electro-Mechanical ResearchCorporation (EMR) of Sarasota,Fla., and was designed to supplanta smaller IBM system and u es athird generation computer for datareduction.

A Naval Presidential Unit Citation streamer was presented to the 18th Aviation Company, 223d Battalion of the 17thA viation Group recently at Qui

Nhon n the Republic of VietnamThe award was made for thcompany's support of the FirsMarine Divi ion in that unit's suc

cessful Chu Lai campaign fromMarch 1966 to September 1967.The coveted blue, gold and reribbon with a Chu Lai inscription was tied on the companguidon by Colonel William R. McDowell, 17th Aviation Groucommander, while the citation waread. The ceremony was held athe company hangar.Symbolically, the award coverall aspects of military operationsIt is a Naval citation awarded t

an Army unit specializing in aviation for its support of a Marinamphibious force.In his congratulatory speec

COL McDowell remarked that because of its involvement in Corps, as well as II Corps, thcompany had a larger area ooperations than 17th Group, ithigher command. He called th18th an outstanding unit.The 18th Aviation Companyflies the U-1A Otter, a small, oneengine cargo and passenger plandesigned to take off and land inshort airfields and in rough terrain

It has been brought to the flighsurgeon's attention that the before-takeoff and before-landinchecklist for the UH-1B, D and Hmodels include a visual check oU. S RMY AVIATION DIGEST


15/68

the bleed air switch. For the pilotof the aircraft, this involves amovement of the head from oneplane to another in space. As apilot, he must be aware that ifthis is done during acceleration ordeceleration such as just prior tolanding or in preparation for landing or during descending turn , aCoriolis illusion could be inducedproducing extreme pilot vertigo.

The Coriolis illusion is a violentdisorienting sen ation of whirlingexperienced by a pilot when hiinner ear gyros (vestibular organs)are stimulated in two planes ofspace simultaneously. This furtherproduces stimulation of a turningsensation in a third plane of space.Together, the conflicting information produces a state of confusionin the vestibular organs of balance.

At night without an adequatevisual reference, a similar illusionmay be felt even when the piiot ishovering prior to takeoff.This condition and the possibleillusion could be eliminated by requiring the copilot to perform thischeck, freeing the pilot for VFR orIFR duties. An alternative wouldbe the performance of the checkprior to hovering and prior to anyaccelerating or decelerating maneuvers. Extreme caution should,therefore, be utilized.* If he U. S. Army ever handsout a medal to a machinefor duty, performance and dependability, the U. S. Army PrimaryHelicopter School, Ft. Wolters,Tex., has a hot candidate.A Hiller OH-23D helicopter,number 57-3007, began its tour ofduty at Ft. Wolters in 1958 andsince has flown more than 10,000hours all on training school assignments.During a 148-month period theaircraft has not been involved ina major accid nt and has had onlyone minor incident with dollardamage of only $232.Although the number of studentpilots who have handled the air-NOVEMBER 1970

craft is impossible to determine,the fact that the ship was on theactive line long before the buildupin the Republic of Vietnam wouldsuggest that one man for each hourmight be a realistic guess.The ship was manufactured byHill r Aircraft Corporation andwas accepted by the Army on 11July 1958. Southern Airways ofTexas Incorporated flight commander Lloyd Wilson completed

the ferry flight from Palo Alto,Calif. , to Ft. Wolters 4 days later

Is a new AR 952 underin DA at this time and, ifwhen will it be out?There is a revised edition of952, dated 8 May 1970, andis available now. This revisionAR 952, dated 125 : ' A I " r l l ~ . V 1968, Change 1 Some

1) fixed wing copilotirement, 2) RVR, 3) mark-er beacon and approach lightoutageQ When on an instrument ap-will radar service auto-t i ~ I I I Y be terminated withoutpilot knowing it?A. Yes, radar service is termi-nated automatically when theIlal1ldinlg is completed or the tower

l f t n t ~ n l a r has the aircraft in sight,i i c h E ~ v e r occurs first (AIM, part

I, page I-59 .Q What s the word on preci-approach minimums withm ~ l r k . l I r beacon and/or approachoutage? Do I raise the de-height DH) or not?

and the aircraft went to work.In logg ing an average of 3: 35hours of daily flying, number 3007has used 150 thousand gallons offuel and has had 10 new enginesand 12 transmissions. From amaintenance standpoint, the aircraft has had all modifications andupdating work performed at Ft.

Wolter.The OH-23D is called Ravenand with apologies to the author

the familiar quote is changed toRaven forevermore.

No, DH is based on glideinformation. The markertells you position only. ~ ~ ~13


16/68


17/68

The U. S Army Combat Surveillance and Electronic WarfareSchool USACSEWS) at Ft.Huachuca, Ariz., trains selected individuals in the use, operation andmaintenance of ground and airborne combat surveillance equipment and in electronic warfare. tis the only Army unit in the U. Sthat offers specialized training inaerial surveillance and electronicwarfare.Special emphasis is placed uponinstruction in the operation of airborne photographic equipment andradar devices at the school. Inflighttraining of prospective airbornesensor specialists covers the camera, side looking airborne radarSLAR) and infrared. The sys

tems are deployed from the OV-1Mohawk surveillance aircraft,manned by a pilot and technicalobserver.In addition to piloting the aircraft, Mohawk aviators are trainedto operate reconnaissance equipment. The technical observer, expert in the operation of all thephotographic and radar equipmenton board the OV -1, need not be aqualified pilot but does receiveejection seat training to ensure es

cape in the event of an emergencywhile in flight. Frequently, thetechnical observer aids the pilotin navigation during the course ofa mission.Instruction in the Camera Branchcourses is focused primarily on twobelly-mounted camera systems anda single nose-mounted camera. TheKA-30 and KA-76 belly-mountedmodels are capable of producingdetailed aerial photographs at altitudes from 100 to 50,000 feet andprovide exposures at angles of 15and 30 degrees to the right or leftof the flight path in addition tovertical shots. Exposing 600 frameson 250 feet of film, the KA-76system incorporates an image motion compensator to eliminateblurred prints caused by the speedof the aircraft.NOVEMBER 1970

Both belly-mounted cameras canbe used at night in conjunctionwith lighting systems to produceadequate surveillance photographs.Until recently, students at Ft.Huachuca were trained to operatethe KA-30 photo-flash cartridge,an extremely powerful explosivetype flare used to illuminate groundareas. Although quite effective below 2,000 feet, only 104 flarescould be carried on a single mission and flash often temporarilyblinded the aviator and silhouettedthe aircraft.To eliminate most of these problems, researchers developed theLS-59 electronic photo-flasher system for use with the KA-76 bellycamera. t is now being testedby students and instructors atUSACSEWS. Similar to a giant

flash bulb the LS-59 illuminates arectangular ground area with a375,000-watt intensity for about 1second with each flash. Becausethe system is electronic, there isno maximum number of availableflashes per mission and the blinding effects produced by flares havebeen virtually eliminated.The KA-60 nose-mounted camera shoots a ISO-degree panoramicpicture of the horizon, providingextensive and detailed coverage ona single exposure of film. Becauseof its low altitude deployment andwide-angle capacity, the KA-60has proven invaluable in the detection of troops and landing zones inthe Republic of Vietnam.Cameras are only the beginningof the surveillance story at Ft.Huachuca, however. All airborne

This LS 59 photo flash unit is entirely self contained.A propeller mounted on the nose of the unit providessufficient power to generate the necessary electricity

15


18/68

tailed knowledge concerning everaspect of enemy operations. Especially in inaccessible areas protected by rough terrain and camouflage aerial surveillance is the onlmeans of gaining advanced tacticainformation. The Mohawk surveillance aircraft equipped with camera infrared and radar systemand manned by well-trained pilotand technical observers is the perfect package of men and machinto do the job.

The KA30 belly camera is ~ x c e p t i o n l l y versatiie Detailed aerialphotographs can be obtained at altitudes from 100 to 50 000 feet

Students at Ft. Huachuca alsenjoy an almost perfect environment for flying and testing of thequipment on which they artrained.The USACSEWS was recentlreorganized to include a schoobattalion containing a faculty company a headquarters and headquarters company and a studencompany. An additional changsaw the Electronic Warfare Schoobecome a department of the combined Combat Surveillance anElectronic Warfare School. Currengrowth trends indicate the probability of a second student company being added in the future.

sensor students receive instructionin the OV 1 C infrared detectionsystem which locates enemy targets by determining temperaturedifferentials between objects andtheir backgrounds. The infraredsystem is deployed from Mohawksurveillance aircraft and is beneficial in coordinating ground/ airattacks by detecting patterns ofenemy troop and equipment movement and providing informationfor the revision of map supplements. Infrared surveillance isespecially advantageous because itis a passive system. That is enemytargets can be discovered withoutthe enemy having knowledge thatdetection has taken place.Side looking airborne radaroperated from an OV-1D Mohawkaircraft provides reconnaissancepersonnel with infortnation concerning metal objects or targets onthe ground located in a perimeteraround and below the aircraft. Aswith the camera and infrared systems both pilot and technical observer are trained in the operationand maintenance of SLAR. A primary advantage of the system isthat the crew is protected fromground fire because it is not necessary to operate directly over thetarget area. In fact SLAR cancover an area 100 kilometers to16

either side of the aircraft facilitating a maximum coverage of 200kilometers although most readingsare taken at ranges of 25 and 5kilometers.Because of the very nature ofthe instruction at Ft. Huachucathe USACSEWS is destined forsteady growth in the future. Aviators and infantrymen alike attest tothe necessity of immediate and de-

The KA60 is a nose mounted camera capable of shooting a lSOdegreepanoramic picture of the horizon It can be employed at very low altitudes

U. S. ARMY AVIATION DIGEST


19/68

The Army aviation warrant officer is here to stay butsince his beginning in 1941 his branch has beencharacterized by conflicting regulations ill-defined concepts and fluctuating management procedures. Howeverthe Department of the Army is making studies on everyarea vital to n Army aviation warrant officer-payrank MOS structure and civilian and military schooling

Major George Coutoumanos

fl[[j Jf]@iD@ iD J j 1iD@

1J@[j] flr:J 1i J fj lJl[Y i J I li J[1 1@ i J

[ J lf J[}][}]f J i //J@ l l[J@ J lJHE U. S ARMY aviationwarrant officer has a promisingfuture. But before the followingdiscussion of his future can bebeneficial, it is necessary to under

stand what constitutes a warrantofficer. Consequently, I sought thisinforma tion from three sources:his wife, his commander and hisbranch.His wife described him as aNOVEMBER 197

hanger for a flight suit that servesas a repository for the parapher-nalia of a pilot and amateur handyman; his pockets contain something like two packs of cigarettes,one lighter, a claw hammer, a boyscout knife, an enamel faucet han-dle and an assortment of screws,snaps, hinges and ball bearings-all of which tend to make himchink as he moves about. In his

helmet bag he carries a survivalwater bag, a laxative, aSpIrIn, acomb, cough drops and, last butnot least, Army issue dental floss.His commanding officer described him as tactless . to whichI said, "Tactless, never Out-spoken, yes. High-spirited, yes.Mettlesome, sanguine, perhaps toa fault. But never tactless."His branch described him as an

17


20/68

The Road head or The viation Warrant Officerofficer appointed by warrant bythe Secretary of the Army. Bypublic law he has rank and precedence that are below those of asecond lieutenant but above thoseof a cadet or NCO. Do not getcarried away by that statement youyoung lieutenants and captains.The W -4 you chew out may be thefather of your commanding officer.)

The warrant's branch said he isa highly skilled technician, provided to fill those positions abovethe enlisted level which are toospecialized in scope to permit theeffective utilization of a broadlytrained, branch qualified commissioned officer.The term. technician, as applied to the warrant officer, indicates the possession and exerciseof skills which are primarily technical as opposed to tactical.

For the purpose of this discus-

sion, the term aviation warrantofficer encompasses those warrantofficers who are pilots-both rotary and fixed wing-commonlyreferred to as a SLAR (side looking airborne rogue) , not to beconfused with the side looking airborne grunt of commissioned fame.The term also includes those warrant officers who are aircraft repair technicians, both rated andnonrated.With the definition of the Armyaviation warrant officer firmlyestablished, the next step is totrace his history. The first reference to the warrant can be foundin the Code of Hammurabi , published by the greatest king of thefirst dynasty of Babylon in 1955B.C. The code stated, If any mortals doth fail to pay their duedebts, a warrant gonna come andpolice up on their pig and goat.

It staggers the imagination to thithat over 4,000 years later twarrant, though not confiscatipigs and goats thanks to technoogy, is transporting them-at leain the Republic of Vietnam.More recently, in 1918 A.D., almost 52 years ago, the rank angrade of warrant officer was estalished. For you young W-1 swiners that's a span of years connecing the turkey trot to the boogaloThe flight officer, today's couterpart of the aviation warrant offcer, was established by the Act 1941. Described as the most sinificant legislation since that whicoriginally authorized the rank warrant officer, it established twgrades: chief warrant officer anwarrant officer junior grade. Heflight pay was first authorized fthose involved in aerial flight.Subsequent to World War Ithe warrant officer structure wasmixture of conflicting regulationill-defined concepts and fluctuatinmanagement procedures. In addtion, expedient utilization practiceemergency executive orders anexpansive wartime legislatiotended to blur the distinction between warrant officers and othecategories of personnel.Following World War II, an incentive concept was adopted whicwas based on the idea of cappineach enlisted career field with warant positions. This practice resulted in a significant increase numerical requirements. It alsaggravated the already inconsisteutilization practices carried ovfrom World War II.The current overall warrant offcer program was undertaken as last alternative to eliminating thcorps. I t was, and still is based othe belief that the Army has a requirement for a separate categorof personnel and that the warran

Army aviation warrant officerstrength h s jumped 5 per-cent during the past 4 ye rs

18 U. S. ARMY AVIATION DIGES


21/68

FLIGHT P Y DIFFERENCESWO OFF DIFF

WI . 130 01 . 170 40W2 . 135 02 . 185 50W3 . 140 03 . 205 65W4 . 165 04 . 240 752lT draws 5 more than W4

officer corps would be used to fillthat requirement.This requirement was finallystated in 1957 by Army Chief ofStaff General Maxwell Taylor,wherein he approved and announced the present warrant officerconcept stating that: The warrant officer continuesto have a definite place in theArmys personnel structure. The increasing requirement tooperate and maintain equipment ofa technical nature provides thatpersonnel possessing a high degreeof technical skill fill these positions,

and that this high degree of technical skill be acquired through ex-tensive training and continuity oassignment Warrant officers will fill thosepositions above the enlisted levelwhich are too specialized in scopeto permit use of the broadly trainedcommissioned officer and be utilized only to fill bonafide organizational requirements and not as areward or incentive for either enlisted personnel or former commissioned officers.This concept was off to a slowstart and subject to a lot of criticism. But the utilization of thewarrant officer, as we know it today, finally got off the ground alittle play on words there) underthe firm and relentless leadershipof several leaders of the day including the first Director of ArmyAviation, then Major GeneralHamilton H. Howze.The aviation warrant officer ishere today; the aviation warrantofficer is here to stay. This can be

dramatically illustrated by pointing out that between July 1966 andJuly 1970 the Army s aviation warrant officer strength jumped from2,960 to more than 12,000.This then is the Army aviationwarrant officer. But what of theroad ahead? Possibly the greatestbone of contention (next to repeated tours in Vietnam) existingin the aviation warrant officerranks is that of equitable flightpay. Action for the equalization offlight pay is being taken and maysoon be forthcoming.I t is strongly believed that anequitable flight pay program willresult in a marked improvement inthe attractiveness of Army aviationas a career for our warrant officerpilots. The annual cost of introducing flight pay equity is estimatedto be less than 5 million, basedon current pay scales and aviationwarrant officer strength. But, if instituted, a minimum increase inretention rates is expected to exceed 9 percent. Thus, from a strict-

C REER UTILIZ TIONP TTERN

Wl-W2 I W3-W4 W4ARAV N SRARAV MASTARAVT AE DC R E E R E ~ V 3A 0PHASE I E PHASE II N PHASE I I I YPH SES C RI SE1- 5 YRS A 6-13 YRS D 14-30 YRSTE

RW OR FW IP INSTR EXAMADV IN TYP.E FLT SAFETY TECHDUAL RATEDMULTI-ENGINE

100B 100C,D,E SUFFIX G101B SUFfiX c SUFFIX C;102A

PILOTPILOT PILOT COMBAT UNITSDIV BDE ETC. NONDIV AVN UNITS RaD TEST ACTIVIESCS a css UNITS DEPOTS SVC SCHOOLS

NOVEMBER 1970 19


22/68

ly monetary standpoint, for an annual investment of 5 million forflight pay equity the Army will receive a minimum annual return ofover 8 million in direct trainingsavings. But more important it willbe adding to a career pool of professionals in whom the Army hasinvested as much as 59 millionper year. However, flight payequity for fiscal year 1971 wouldrepresent an unprogramed fiscalitem. Therefore, a method or sourceof funds from within the approvedArmy budget will need to be identified. Still the case for equitableflight pay is strong and significantlyit is in keeping with, and essentialto, the all-volunteer Army concept.

Advanced schooling, both civiland military, is becoming moreand more 'important in all spectrums of the Army-most especially in the aviation warrantofficer corps. While the initial aviation and maintenance training received by thc aviation warrantofficer contains sufficient instruction to permit performance of pilotand/or maintenance duties undermost conditions), it does little tofurther his understanding of tactical unit operations. The tacticalenvironment in which the aviationwarrant officer exercises his skillsdictates that he possesses this tactical knowledge.As a result of the requirement

of the aVIatIOn warrant officer toobtain additional qualification, refresh and update existing knowledge and provide training in newlydeveloped techniques or equipment,a progressive educational careerpattern has been deveioped: theintermediate and advanced warrant officer career developmentcourses.

The purpose of these courses isto provide a career developmentprogram to selected aviation warrant officers in order that the Armycan maintain a base of highlyskilled, professional aviator andmaintenance technicians who arecapable of assuming aviation re-lated positions o greater responsi-bility

As the primary components ofthe Army aviation warrant officercareer development program, theintermediate and advanced courseshave the specific objectives of providing an incentive for excellencethrough established standards offormal schooling. The goal is tofurther develop the aviation warrant officer's knowledge of militaryand military / aviation functions andto expand his pilot skill capabilitiesin phase with his career development program.The civil schooling goal for aviation warrant officer is at least a2-year college equivalency. Currently, the aviation warrant officer

corps has approximately 80 pecent of its personnel seeking dgrees full- or part-time in collegeLooking forward, efforts are uderway to establish an aeronauticengineering college in the FRucker, Ala., area. Queries abeing made to Georgia Tech athe University of Alabamamention a couple while EmbrRiddle is establishing a facilitThe ultimate objective is to offan associate degree in basic aernautical engineering. It is envsioned as a 2-year degree prograopen to aviation warrant officedesiring a 2-year degree undbootstrap.

The road ahead for the aviatiwarrant officer also holds grepromise for additional grades rank and pay. The adequacy of tpresent promotion system is goonly as far as it goes. Currentlwarrant officers are promoted froW01 to CW2 in 1 year, CW2CW3 in 4 years and CW3 to CWin 4 years. It is conceivable thto have a basic entry warrant ofcer candidate, 18 years old anhaving less than 1 year actifederal service, make CW 4 in lethan 10 years and having only years to go at age 28. This is, anwill continue to be, more the ruthan the exception. What does thyoung man, this highly traintechnician, have to look forwa

AVIATION WARRANT OFFICER PROFILEENTRY IN 50 S

YRS 8 116 21EM I w11 W W3 I W4

ENTRY IN 60 SYRS 2 5 5 10.3EM IW w2 W3 I W4

20 U. S ARMY AVIATION DIGE


23/68

PRESENT AVN MOS STRUCTURECODE TITLE100B RW Pilot-Obsv Util100C RW Pilot-Med Trans100D RW Pilot-Hvy Transl00E RW Pilot-Attack101B FW Pilot-Single Engine100C FW Pilot-Multi-Engine101D FW Pilot-Surveillance A/ C102A FW RW Pilot671B A CRepair Tech (Nonrated)671C A CRepair Tech, RW Rated671D A CRepair Tech, FW Rated671E A CRepair Tech, RW/ FW Rated

SUFFIX CHARACTERSSUFFIX QUALIFICATION6 Instrument ExaminerB Fit Safety SpecialistC Instructor PilotD Aeromed Evac PilotT A/ CArmament Maint (Transitory)

to then? Nothing but longevity payraises. To make a long story short,the best of all possible alternativesis the addition of grades CW5 andCW6 Such a proposal has passedthe talking stage and is now underconsideration at the Department ofthe Army.

To this point, use of the aviationwarrant officer can be likenedmore to nonutilization than to utili-zation. That is , the surface hashardly been scratched when itcomes to using the Army aviationwarrant officer to his fullest poten-tial. However, care must be taken,and is being taken, not to eliminatethe distinctions that identify thewarrant officers as a separate cate-gory of personnel.In line with this, positions in allaviation fields are being reviewedfor conversion, either way, com-missioned to warrant or vice versa.Unless the position clearly calls fora technician rather than a multi-functional manager or commis-sioned officer, that position will notbe converted. Those positions that

NOVEMBER 1970

are finally settled on then shouldbe established on the basis of mili-tary occupational specialty (MaS)and repetitive assignments withinthat MaS should be made tosustain and increase technical ex-pertise in a chosen field.It also is recognized that addi-tional primary and duty MaS areneeded. The expanding role ofArmy aviation and the aviationwarrant officer's vertical trend inspecialization call for, and are in-dicative of, new warrant officermilitary occupational specialties.Commanders cannot accuratelyrequisition personnel with addi-tional skills over and above thebasic MaS qualifications withoutincluding extensive comments on

the requisitions.Additionally, many aviation war-rant officers who are permanentlygrounded and who cannot as a re-sult function in their primary MaSare often retrained for nonaviationrelated MaS and forever lost toArmy aviation.Therefore, two new MaS arebeing proposed: the aviation stafftechnician-rated (MaS 103) andthe aviation staff technician-nonrated (MaS 104).The rated aviation staff techni-cian MaS is intended to be a dutyMOS. That is to better identifyspecific individual qualifications tomeet the increase in specializationareas. The nonrated aviation stafftechnician MaS is intended to dothe same thing but be a primaryMOS. Aside from giving additionalcareer growth opportunities tothose aviation warrant officers whoare not rated, it will enable Armyaviation to retain those who werepreviously rated and have beenpermanently grounded.A few of the areas that may w ellbe contained in the 103 and 104MaS structures include: Airfield operations. Air traffic control. Aviation test and engineering. Aviation combat development.

A viation armament and firecontrol.The road ahead for the Armyaviation warrant officer has withinit: Equitable flight pay. Advanced military and civil

schooling. Additional rank and paygrades (under study). Promotion and utilization inchosen specialty areas. New areas of specializationwith increased responsibility.In the words of Major GeneralDelk M. aden , former comman-dant of the U. S. Army AviationSchool: The fields in which ex-perienced warrant officers can beemployed are limited only by the

imagination of the person con-cerned. Indeed, those concernedare both commissioned officers andwarrant officers. They are you andme, and history has shown ourimagination to be boundless. :.,..:::4

PROPOSED MOS STRUCTURECODE TITLE103 - Aviation Staff Technician (Rated)A Avn Personnel Mgmt

B Avn SafetyC Fit Tng / StandardizationD Avn OperationsE Air Traffic ControlF Avn Test Engineering (R D)G Orgn / Equip, Combat DevelH Avn Maintenance MgmtI Avn Supply MgmtJ A/ CArmament Fire ControlK AvionicsL Aide-de-Camp104 - Aviation Staff Technician(Nonrated)A L Same as for 103

SUFFIX CHARACTERSSUFFIX SKILL LEVEL1 Basic Technician (WI-W2)2 Senior Technician W3-W4)3 Master Technician W5-W6)

21


24/68

Check Your Struts: During yourU-8 preflight ensure that there is aminimum of 3 inches extension onthe main struts. Any amount lessthan this could result in ottomingut and structural damage on

landing. Also, the nose gear shouldhave at least a 5-inch extensionof the strut for the same reason.The weight of the aircraft must beconsidered when checking strut extension;. therefore, to obtain naccurate measurement, there shouldbe a full load of fuel on board. fthe aircraft struts meet minimumrequirements without fuel, additionof fuel 1,380 pounds capacity)could cause an unsafe strut position. Takeoff weight or landingweight should be considered whenservicing the shock struts.

Cleaning Tips: Use cleaning solvents only in well ventilated areasand preferably outside. Never usesolvents near electrical equipmentor an open flame.

Maintenance Tips: Know the toolsin your toolbox and conduct aninformal inventory of them aftercompieting each job. t is a goodhabit to develop and will do wonders toward eliminating engineFOD.Learn to police the engine inlet~ f your bird as the last step

inten nce S we l ke betlerc re of your ircr ft

prior to securing the cowling andfairings.Check your torque wrench calibration inspection tag. An inaccurate torque wrench may result in anincomplete mission for your bird.

Installation Of Tail Rotor DriveShaft Cover Hinge Rod UH.IA, B,D, H: Installing the tail rotor driveshaft cover hinge rod on the UH-laircraft is quite a task under idealconditions, even back in field maintenance areas. In forward base

camp areas this job was expediteby using drill, pneumatic air gun)-inch straight drive, reversibltype, by attaching the air gun tone end of a rod with one maguiding it to the hinge eyes and another man at the center of the roto hold it level. Running the wirthrough small tubing or pipe wilmake it much easier and safer) tohold the rod level. A safe operatiocan be had by using an air pressure regulator to control air pressure and by using a maximum ohalf drill speed. This will aid inputting the rod through hinge eyes

U. S ARMY AVIATION DIGEST


25/68

attersA light coat of GOB grease orequivalent type grease may be puton the rod to ease sliding it throughthe hinge eyes. Also, file the leading end to a smooth round domeshape. This helps prevent the cutting of the hinge eye surfaces. Anyscratch hinders smooth and easyslide through. This same procedureapplies to the ventral fin drive shaftcover rod as well with the exception that only two men are needed,the lead man and the air gun operator.

Grease It Right: When lubricatingthe counterweights on the U-6 propeller, use only the specified grease(MIL-G-7711, general purposetype). Many people not familiarwith the U-6 have thought it bestto use high temperature grease.However, experience has proventhat high temperature grease causessluggish prop operation when usedin the counterweights.

Beware Mr. Clean: f aircraft hasto be washed during periods wheretemperatures are freezing and below, water should not be used; itwill seep between aircraft skin,freeze and cause rivet heads to popoff. Other damage can also occurby water getting into componentswhich cannot drain properly. Wemust remember when water freezesNOVEMBER 1970

it expands, leading to structu,raldamage to the aircraft. To washaircraft, use a shop rag dampenedin proper cleaning solvent and useanother rag to wipe and dry upsolvent.

Get The Right Temperature: t isvery important to use correct temperature when heat treating is donewith an electric oven or furnace.You can find the temperaturecharts in TM 55-408. Material thatis not properly treated can crack,burn, buckle or just not reach thedesired hardness. Cooling is alsovery important in the process.Cooling too fast or too slowly willhave the same effect on the material as incorrect heating.

OV l Engine Oil Servicing: Overfilling the OV 1 engine oil tankcan be prevented if the oil level ischecked immediately after shutdown. Overfilled engine oil tankswill vent onto the horizontal andvertical stabilizers causing de-icerboot and paint deterioration.

Aluminum Storage: Do you knowthat sheets of aluminum should bestored upright on ends, separatedwith sheets of paper or some othermaterial to prevent scratches in

handling the metal. Where aluminum sheets have been stacked fiat,handling by sliding or pulling outa sheet will cause scratches andrub off the coating that preventscorrosion. The resulting corrosioncauses many expensive aluminumsheets to be condemned.

New Tiedowns: New tied owns forthe main rotor blades, UH-1B, Dand H model aircraft are nowavailable. They should be orderedto prevent d m ~ e to the tail boom.

Use Of Aviation Fuels: Aviationmaintenance personnel are reminded that aviation fuels are to beused for their designed purposeonly. Fuels are not o be used asa cleaning agent for any reason.Maintenance supervisors at alllevels should remind all personnelthat disregard for the proper use offuel can cause serious injury ordeath and loss of property.

For Safety: On all UH l serieshelicopters ensure the handle as.sembly, ejection on pilot's and copilot's doors is saftied with, andonly with, opper safety wire. Inthe event of an emergency it'stough pulling for the pilot when it'sbeen secured with steel wire. 2)


26/68

The LOH FAC Tactical Fighter Teamaptain Richard T ross


27/68

41 ,''' ..

/ .

THE COORDINATION between U. S. Air Force tacticalair support and our U. S. Armyunit, B Troop, 7/17 Air Cavalry,in 1968 and 1969 in the Republicof Vietnam was outstanding. Wefelt this was due in part to a closepersonal and professional relationship with the Air Force forward aircontroller FAC). This is not always possible to establish, but dueto the proximity of our contingentat Phan Thiet to all the people weworked for and with, we developedunique and highly effective procedures which hinged on good rapport and teamwork.The Air Force F AC was a fighter pilot who was also qualified inthe 0-1 Bird Dog. He coordinatedjet fighter strikes on enemy targets.The F-I00 was normally the typefighter used in our area for tacticalair support. After many of the missions our OH-6A LOH) pilotsand some of the AH 1 G H ueyCobra pilots would go over to the F ACquarters and, relaxing over a coldbeer, discuss the mission, the results obtained and possible ways toimprove operations. The oppor-

tunity to sit down with supportunits has obvious benefits and isone of the reasons we were ableto develop a method of pinpointtarget marking in an effort to increase the percent of damage doneto the enemy.Before I continue with an example of a typical operation, it isnecessary to briefly review how theAir Force FAC normally runs anairstrike. Here are a few of thebasics.The F AC, after locating a target, fires a white phosphorous (WP)rocket into the general area of thetarget, then directs the fighters onthe target. After the airs trike isover the F AC conducts a battledamage assessment from his 0-1.Obviously the accuracy of thismethod depends upon getting themarking rocket on target the firsttime. Generally, the percent ofdamage done was good but throughour discussions we devised a wayto increase the percentage.The method of operation weagreed upon with the sector FACwas that upon receiving a requestfor an airstrike from us he would

immediately initiate a requesta flight of F-I00s, and then flyour area. After the FAC arriin the target area we would ghim all the information we hwhich he would pass on to the he was vectoring to the area. Othe jets were on station, brieand set up on their attack pattea team of LOHs would mark center of the target and move of the area so the FAC could the jets in.By having the jets drop only bomb apiece, then move back itheir holding pattern, we cosend the LOH team back into area, do a quick damage assement and remark the target. repeating this process until .fighters had expended their onance stores, we found the pcentage of damage was substtially increased. Now let's looka typical mission. Using two LOand two AH-IG HueyCobras,will conduct a high speed asweep of the gently rolling, sctree covered area to our souknown to us as Southern FStrike Zone.


28/68

Takeoff is at 0730 and since wehave to travel only a short distance, we arrive in the mission areain about 5 minutes. I drop downon the treetops, followed by mywingman, and we begin high speed,east-west sweeps moving north.For a while the scenery flashesunder my LOR in endless monotony. The trails which criss-crossthe entire area show recent use sowe call everything of importanceto the attention of the ever circlingCobras, whose crewmen relay allreports to base operations.As I pass over a sparse area inthe woods a quick movementcatches my eye. Turning slowly Icome back over the area and findtwo Viet Cong (VC) hiding undercamouflage covers, similar to Armyissue poncho liners.I call my wingman and tell himto move out of the area so theCobra pilots can concentrate onmy area. We have found throughexperience and practice that thistactic, when we are not receivingfire, eliminates confusion and reduces the time necessary to locatewhich LOR has the target.Lead Cobra calls to say he hasme in sight. I have my observerselect white phosphorous insteadof smoke to mark the target. ThenI call lead and ask him to tell mewhen he starts his run so I canmark the target. This is anothertrick we've found useful. The LORcan mark the target, move out ofthe area and eliminate the normaltime lag created by the Cobras having to wait for the mark to comeup before they start their firingpasses. The LOR is gone, the markcomes up and the inbound Cobrascan punch off their rockets, increasing the chance of catching anyVC trying to get away from thesmoke mark.As soon as I mark the area Icome hot with the minigun, thenwheel the LOR out of the area andover to my wingman. The Cobras26

fire pair after pair of rockets intothe area, throwing tree limbs, rocksand a cloud of brown dirt high inthe air. After two passes each theAR 1 Gs hold off and we go inagain in the LOR. Once back inthe area we start locating singleand multiple entrance bunkers,each well camouflaged and obviously still in use.

Lead Cobra meanwhile hascalled back to base and has the AirForce F AC request a pair of fighters before he takes off to join us.The FAC arrives in the area inabout 15 minutes and assures usthat the fighters are being sentfrom Phan Rang and will be in thearea in 25 minutes.My wingman and I continue tosearch the area, reporting everything new that we see. When thejets arrive on station the FAC givesus their URF push (radio frequency) then briefs the jets on thetarget, direction of attack and allother data necessary for their mission sheets. Re then requests atarget mark from us. I go into thecenter of the target area and dropa white phosphorous grenade for amark. I can hear him talking to thejets as my wingman and I wheelout to the north to a safe holdingdistance.The first jet (Chalk One)screams in dropping one 750-pound delay bomb and is followedby the wingman who also dropsonly one 750-pound bomb. As mywingman and I start back into thearea the FAC calls the jets and hasthem hold high and dry. Thickbrown smoke obscures most of thearea.The first bomb had missed thetarget area by 50 to 75 meters ormore and the second bomb hadmissed by over 100 meters. I callthe FAC and give him the information. Chalk One requests us togive him a colored smoke and sayshe will blow the smoke away.I go back to center of target andmy observer drops two red smokes

followed by a white phosphorougrenade. By marking the area thiway the jet pilots see the initiamark-the white phosphorous grenade-right away and then the colored smoke which comes up morslowly, giving a more lasting markWe call clear and the jets starback in. Chalk One drops one 750pound bomb which from where am appears to be dead centerChalk Two follows him with a repeat performance. The jets oncagain hold high and dry as we return to get a bomb damage estimate. True to his word Chalk On

had blown away the smoke in addition to destroying two bunkersWe remark the area and move ofwhile the jets drop their remainingloads, and then strafe the area with20 mm Vulcan cannons. When thejets finish their firing runs theydepart station and my wingmanand I go back again to get a finabomb damage assessment.The jets had done a good job inthe overall destruction of the bunker complex. Of the 12 bunkers inthe area, three large ones had completely disappeared, five otherwere partially or completely destroyed, two were damaged and theother two were undamaged. TheF AC relays this information to thedeparting jets so they can have althe data they need to fill out theimission reports.

The troop commander, flying inthe command and control helicopter, calls us to say that he is goingto bring out our organic infantryplatoon and insert them to sweepthe area in an effort to gather intelligence data. After the sweep iscompleted and the infantry extracted, we head back to the basecamp.This description of this missionis greatly simplified. But it reflectsthe rapport and effective teamworkour unit had established with anAir Force tactical air unit inachieving our common goal of destroying Charlie's war f f o r t ~

U. S. ARMY AVIATION DIGEST


29/68

Chafing Ofircraft oses

oss of hydraulic pressure is not conducive to yourgood health Inspect the hydraulic hoses often andknow all of your preventive maintenance procedures

"Ah, there's the rub "

Major Vincent G. Ripoll and Donald R Artis Jr.

T HE MONTHLY MaintenanceSummary published by theU. S Army Board for AviationAccident Research (USABAAR)regularly contains numerous references to aircraft accidents and precautionary landings caused byhydraulic system discrepancies. Thesummaries indicate that in fiscalyear 1969 approximately 37 percent of all reported accidents andprecautionary landings with confirmed or suspected maintenancecauses were attributed to hydraulicsystem failures. A significant portion of these hydraulic system failures are ascribed to chafed hydraulic flexible hoses.There are many reasons whyhydraulic hoses chafe: improperdesign, improper maintenance procedures established by the manufacturer, improper or incompletetechnical manual (TM) instructions, or poor maintenance practice. These deficiencies usually result in chafing of flexible hoseseither by hose-to-hose contact orby contact of the hose with a structural element.Hydraulic system plumbing installations found in Army helicopters undergo a fairly rigorqus development cycle. The designer, using the practices and proceduresNOVEMBER 1970

developed over the years, designsthe installation and takes into consideration such factors as lineflexure under static pressure, dynamic flow conditions and vibration, temperature, etc. A plumbingmock-up is then built to check andrefine the design and to assure thatthe proper support is provided atthe proper location to precludepossible chafing conditions. Duringinitial ground and flight testing ofa new aircraft, the plumbing installations are inspected frequentlyto detect any chafing or other problems. Changes are made to the testaircraft as necessary and testingcontinues. All changes resultingfrom this development process arereflected in the design drawings andmaintenance manuals.

The production aircraft are allmanufactured supposedly in thesame manner, and if the manufacturer's quality control proceduresare adequate, hydraulic hose chafing should not occur. But, we knowin fact that it does occur. Why?During an i n v e s ~ i g t i o n of thisvery serious problem, the U. SArmy Aviation Materiel Laboratories (AVLABS), Ft. Eustis, Va.,inspected several AH-IG and UH-1C helicopters at random andfound that three out of four had

chafed hydraulic hoses. An investigation of the cause of the chafingand why it was previously undetected revealed that instructions inthe TM regarding positioning ofsupport clamps and brackets wereinadequate.Various publications have contained recommendations for moreadequate supervision to ensure thatcorrect procedures are followedand to push, preach and practiceby the book maintenance, inspections and administrative functions.However, are the TMs telling ourmechanics in the field the properway to perform each maintenanceaction? A review of TMs 55-1520-221-20, -35 , -20P and -35P hasrevealed several specific deficiencies. To simplify the explanationof these deficiencies, reference willbe made in this article to the TM55-1520-221-XX AH-IG) series;however, the findings and recommendations apply to most TMs inthe 55-1520 series.During a review of the TM itwas found that -20 does not indicate the use or position of clampsto restrain hoses. Many paragraphsare dedicated to the removal andreinstallation of hydraulic systemcomponents. Statements regardingthe hose assemblies read: Discon-

27


30/68

nect hydraulic hoses from orConnect hydraulic hoses to fit-tings. . . . But an explanationcould not be found describing themethods for disconnecting hoses ortelling how many clamps to use toprevent or correct chafing conditions. Further, -20P and -35Pshow the installation of on set ofclamps on hoses that are 20 and 24inches long. Chapter 18, sectionVIII of Technical Bulletin TB)750-125 explains the use of

c l a ~ p s but mainly for use in supportmg hoses. Very little is saidabout the separation of hoses toprevent chafing. TM 55-405-7gives the shop practices and replacement criteria for Teflon hosesbut again does not elaboratepreventive measures for chafing.Even the right and wrong fig-ures in both manuals, althoughvery explicit, deal very little withthe chafing problem.Investigations conducted byA VLABS also have revealed thatchafing situations can be encountered because of the method usedto cut, fabricate and replace a hose

AHIG hydraulic hoses are in contactdue a twisted hose even though therequired clamps are correctly in place28

A United States Aviation Laboratories sample of an aircraft hosethat has failed due to chafing

assembly. Usually the old hose isused as a pattern for the new one'or, if the old hose is not available'

.new one is patterned againstSImIlar hose from another aircraft.Is there anything wrong with thispractice? Nothing whatsoever ithe hose used as a pattern wasmade by-the-book. But, if that patt ~ r n was manufactured from a preV OUS pattern, it can easily be seenthat any error in the fabricationwill be repeated each time a newhose assembly is made.Since crew chiefs and mechanicsin the field operate through TMs-20, -35 , -20P and -35P, it can beassumed that only one clamp willbe installed if only one clamp isshown and the field fabrication ofa hose assembly will only be asgood as the process that is explained in the manuals. This is adiscrepancy that the crew chief inthe field can do little to rectify directly. However, he is responsiblefor assuring that his aircraft isavailable and safe to fly So whatshould he do to minimize the pos-

sibility of hydraulic system failuredue to flexible hose chafing?A VLABS recommends the following:Perform more frequent checksof hydraulic hose installationsa.nd m o r ~ thorough daily inspectlons. ThIS will allow detection ochafing problems before failuresoccur.Consult the TM to assure tha

~ h e flexible hoses are supportedIn ~ c c o r d a n c e with the design reqUIrements. Where hoses are nosupported against the structureof the aircraft use separationclamps as necessary to prevenchafing between hoses as long asthe clamps used will not restrichose travel or cause the hoses tobe distorted during the flexingcycles. Once a clamp has beenadded to avoid chafing performa systematic inspection of thehose assembly to detect any further possible failures of the newinstallation. In using a separation

c a m ~ , be sure that the clampsIze S appropriate to the hosesize by referring to T8 750-125table 5 page 11. If T8 750-125is not readily available use the

U. S ARMY AVIATION DIGEST


31/68

HOSE SIZE TEflON MIL-H-2726i) - 3 -4 -5 6 -8CLAMP SIZE MS 21919 ) 5 6 7 8 10

values that appear in the tableabove.When replacing a hose assembly ask your direct support (DS)unit to paint a thin stripe of zincchromate the length of your hoseassembly. This will help you toavoid or detect twisting duringinstallation.If chafing problems are beingencountered and the plumbing installation is in accordance withthe TM, then point this out to themaintenance officer because itcould be a serious problem affecting not only that particularaircraft but also the rest of thefleet. The maintenance officershould in turn seek to have the

T clarified and take action todevelop, or have developed, afield fix.Report problems of this natureunder the equipment improvement recommendation programso that AVLABS will be able touse the data effectively.

At present, A VLABS is investigating hydraulic hose chafing problems and potential solqtions. Onemethod of preventing chafing is tocover the lines themselves with asubstance that makes it immaterialwhether they contact or not. Testing was begun in November 1969at AVLABS on steel-braided Teflon hoses to determine their chafing characteristics and to find asolution to preclude their chafing.Various materials are being examined to determine whether theywill increase the mean time between failure (MTBF) of the hosesunder test conditions. Nylon coil,A thin line of zinc chromate paintedon an aircraft hose with slippagemarks on the fitting permits easy,immediate detection of any twisting

NOVEMBER 1970

Teflon coil and polyvinylchlorideoverwraps have been examinedwith very encouraging results forthe nylon coil.Testing to date indicates thatnylon overwrap represents an improvement of at least 16 times theMTBF of unprotected steelbraidedhoses. Therefore, i aircraft hoseswill last on the order of 20 hoursunder flight conditions when rubbing against each other, then thenylon coil overwrap could conceivably extend the time to failureto at least 320 hours. Time constraints to date have not allowedany single test sample in thesetests to run longer than 27 hours,so a specimen that lasted at leastthat long was removed from thetest fixture. Therefore, the nylonwhich lasted 27 hours with only asmall amount of wear could conceivably have lasted much longerthan indicated by these tests. Thelife characteristics of hoses rubbing against aircraft structure willbe investigated, and the fixes thatperformed well during the hoseagainst-hose test will be examinedto determine their qualities underthese additional test conditions.Teflon tape will also be examinedto determine its characteristics andto evaluate its worth.

To solve the problem of hydraulic hose chafing in future Army aircraft, AVLABS will make recom-

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