Army Aviation Digest - Jul 1969

8/12/2019 Army Aviation Digest - Jul 1969

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AVIATION WO CAREER COURSE- Late Changes -

The first two Intermediate coursesbegin 7 July 1969 and 26 January 1970and will last 22 weeks and Z days witheach having an enrollment of 100 students. The first two Advanced courseswith 60 students each will last 23 weeksand 2 days and will begin 20 August1969 and 19 January 1970.Qualifications for the Intermediatecourse include three years service as arated aviator or an aircraft repair technician non_._ra-::;t:-e_d.-.).--:-:-:-::,....-....,....._Because of multiple typographicalerrors in the USAASO Sez article onpage 64 of the June issue, we are reoprinting that portion of the article pertaining to the new Fixed Wing SpecialIFR procedures.On Fixed Wing Special VFR TheFAA has recently revised proceduresreducing restrictions, imposed in April1968, against Fixed Wing Special VFRFW jSVFR) flights in control zones.A new type of operation, Fixed WingSpecial IFR FW j SIFR), is being permitted in the control zones specifiedin FAR Part 93.113. These are preplanned operations which will be permitted in less than basic VFR conditionssubject to the following: Operations must be conducted under the terms of a letter of agreementobtainable in conjunction with waiversto FAR 91 and are limited to certainfixed wing aircraft having a frequentlyrecurring need to operate there in lessthan basic VFR conditions. Operations must be conducted byIFR qualified pilots in IFR equippedaircraft.

In general, these special operationswill be handled the same as IFRoperations except that a fixed altitudewill not e applied, ground contactmust e maintained and visibility muste at least 1 mile.Restrictions against Fixed Wing Special VFR FW j SVFR) operations tocontrol zones other than those specifiedin FAR Part 93.113 have been eliminated except that VFR FW jSVFR)traffic may not cause delay to IFRtraffic.

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Sir:Major Christensen's article "Turbines

Demand Computer Planning" in theOctober 1968 AVIATION DIGEST is ofparticular interest to those of us in theMarine Corps flying UH-ls. His coverage of the TS3-L-ll is most certainlybroad yet specific and thorough. Onearea, however, which was not coveredbut needs some discourse involves thephenomenon of hover/ taxi and takeoffat overgross weight conditions, so oftentrue for UH-ls configured as gunshipsoperating in high ambient temperatureconditions of the Republic of Vietnam.All UH-l pilots have experienced atone time or another the surprising factthat if they pull pitch beyond maxpower causing a reduction in N" below6600, the ship will often become airborne. How can this be pos ible whenthe author has carefully pre ented hiscase howing the direct relation hip ofreduced N to SHP developed?

Simply put, it boils down to increasedrotor efficiency at some lower rotorrpm through blade design. 6600 N .,with its attendant rotor rpm will notproduce optimum lift efficiency a compared to some lower rpm , but it doesrepresent the best trade-off between optimum hover and high speed efficiency.A canvass of UH-l gunship pilotsfor first-hand reports of RVN operations will reveal, I'm ure, the fact thata great number of initial liftoffs fromprepared or cleared surfaces necessitated an intentional u tained N " droopuntil translational lift was achieved.The ability of the UH-l to hover/ taxiand take off at max power with an N 2LESS THAN 6600 yet not be able todo at 6600 is fact not fiction Thisis an area of operation which needsmore analysis and dissemination.Granted, it does border the edge ofthe envelope and arbitrary bleed-off ofN 2 can bring disastrous re ults.Pilots must appreciate the narrowingsafety margin when less than 6600 N"at max power is employed in order tobecome airborne. Bar tales of individualexpertise fail to properly educate. Iwould recommend an amplification ofthis phenomenon-advantages and pitfalls-perhaps by MAJ Christensen

whose previous article was of enlight-ment.Major A. T. Common, USMCH&HS-l , MWHG-1Aviation Safety OfficerFPO an Francisco 96602 The technique discussed in the letter

from MAJ Common is familiar to mostaviators who fly or have flown theH-l under heavy load conditions. Few,however, have a complete understanding of why t works.The simplest explanation for the increase in thrust at reduced rotor rpm

is the resul tant change in drag forcesacting on the rotor. A helicopter rotorin hovering flight is acted upon by twoseparate drag forces. The first, profiledrag, is a combination of form dragand skin friction drag, and remainsrelatively constant as long as the rotorspeed is not changed. Induced drag, asthe name implies, is a result of changesin angle of attack of the blade inducedby the pilot to produce thrust. Unlikeprofile drag, induced drag varies constantly as the angle of attack of theblade, and thus thrust, varies.A simplified illustration of the effectsof these two drag forces can be seenby observing a helicopter in operation.When the engine is started, the rotorwill start to turn slowly. As power isincreased, the rotor will speed up untilthe desired operating rpm is reached.At this point, most of the power beingproduced by the engine is used to overcome profile drag on the rotor blades.As the pilot increases pitch on theblades . to lift the helicopter off theground, he is creating induced drag onthe rotor, and more power will be required to maintain a constant rotorspeed. There will be practically nochange, however, n the power used toovercome profile drag, since it is basically a function of rotor speed.f the rotor speed is reduced, therewill be a corresponding decrease inthrust, induced drag and profile drag.In measuring these changes, however,we find that the changes in thrust andinduced drag are functions of the squareof the rotor speed V2), while profiledrag is a function of the cube of the

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This article advocates ta ctical airmobility as essential to the successful conduct of internal defense operations in the developing countries.It is hown that the e countries could be subject to the threat of insurgency and should be prepared to conduct operation in difficult terrainwhich restricts the mobility of conventional force The advantages oftactica l airmobility are examined and the capabilities of an airmobileforce are highlighted. It i concluded that the United States shouldencourage the developing countrie to organize airmobile forces tocounter the threat of insurgency. Our assistance in equipment andadvisory per onne will be required

CTIC IRMOBILI YI NSURGENCY constitutes oneof the most immediate threatsto the security of the developingcountries of the world, yet few ofthese countries have equipped andtrained their armies for counterguerrilla warfare. Instead, theirmilitary budget has been allocatedfor the purchase of jet aircraft,tanks and warships; and theirforces have been schooled in thetactics and techniques of conventional warfare. Their desire to emulate the more modern nations ofthe world, coupled with their perception of their basic national interest, has led them to developforces that are better designed tocombat foreign aggression than to

olonel Robert S Kellar

combat the immediate problem ofinsurgency.Hopefully, prestige forces willserve as a deterrent to a conventional invasion of a country, butthey will not deter insurgent activities taking place within a country.f a military estabHshment is notcapable of efficiently eliminatingan insurgent buildup, the insurgency can continue to grow until

it threatens the very existence ofthe country. This major threat tothe developing nations of theworld, insofar as it is military, canbe eliminated if they develop asmall, elite force trained andequipped for antiguerrilla warfare.An airmobile force, utilizing the

tactics and techniques developedby the 11th Air Assault Divisionand proven in combat by the 1sCavalry Division (Airmobile), isan answer to the threat of insurgency in the developing areas ofthe world.Modern technology has madethe developing countries aware ofthe tremendous gap between theirshare of the world's economicwealth and that of the modernnations. Some of these countrieshave been independent for manyyears while others have clamoredfor and gained their freedom within the last decade. Neverthelessnow they are all in a hurry to closethis gap and to complete the diffi-

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Guerrilla forces take advantage of protective environmentsthat hamper operations of conventional mechanized armiesn airmobile force is able to counter this advantage

cult transItion from a backwardnation to one enjoying all thebenefits of a modern ociety. Amore gradual transition such asexperienced by many nations ofthe west i not acceptable to theseemerging nations.

In a country undergoing radicalchange conditions can be createdwhich may promote the formationand growth of groups that are indisagreement with the nationalpolicies of the exi ting government.In their hurry for rapid modernization these dis ident groups arenot content to seek or may beprecluded from seeking an orderlypolitical olution to their grievances. They usually resort initiallyto acts of civil disobedience andother measures short of outrightmilitant force to emphasize theirpoint of view. f these tactics donot achieve the desired re ultthese groups may turn to the use of4

violence to overthrow the incumbent government.The same modern technology

which conveyed to them the realization of their substandard condition in life also will enlightenthem on the methods and procedures for orgamzIng guerrillamovements. The guerrilla doctrineof Mao Ho Chi Minh and Ca troare well pu bl icized in these areasof the world. Trained revolutionaries are readily available to offermaterial aid and assistance in or-ganizing and initiating guerrillawar Thus when a group choosesto re ort to violence the ingredients are present which may fosterthe growth of an organized in-urgency.

The embryonic nature of a guerrilla movement requires that itsgrowth be acomplished in an environment where it is protectedfrom the military force at the dis-

posal of the government. A guerrilla force seek refuge in the mostinaccessible portion of a countryuch a jungles swamps and moun-tainous terrain. In these areasroads and other means of communication are virtually nonexistent.

Th terrain i rugged and impassable except for a beast of burden ora man on foot. This is the environment where the guerrilla forceestablishes a base and build itstrength for future operations. ttrikes out from this sanctuary onlyat opportune times to attack selected target with overwhelmingforce.The guerrilla force feels ecurein this protective environment withthe knowledge that a conventionalmechanized or motorized armycannot penetrate it base area. Inorder to seek out and destroy theguerrilla the conventional army isrcduced to footmobility and forced



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to operate under conditions whichpre ent the initiative to the guerrilla. By carefuly selecting his areaof operations the guerrilla eliminates the mobility and firepower advantage which normally are heldby the conventional force.The ucce sful conduct of internal defense operations dependon the ability of the governmentforces to seize the initiative fromthe guerrilla. Thi require thecapability to overcome the obstacles of the terrain thereby gaining mobility and fir power over theguerrilla with the ultimate purposeof placing deci ive forces on theground to defeat him. This is whatan airmobile force i capable ofdoing.The war in Vietnam is characterized by an exten ive use of airmobility in the conduct of internaldefense operations. This is not thefir t conflict however in which airmobility has been utilized to enhan e the footmobility of thsoldier and to overcome the advantages which the terrain affords theguerrilla.The British pioneered the u e ofairmobility in internal defense operations in their battle to save

Malaya from communi t insurgentsduring the period 1948 to 1960. Aforce of 26 medium helicopterflew a total of 20 000 orties transporting troops over jungles wherethe rate of movement on theground wa re tricted to 800 to1000 yard per hour. This rapidmovement of troops into jungleclearings in the area of operationssaved s many of 10 days of unproductive marching time for usein active patrolling in the operatingarea. Resupply and evacuation ofcasualties were performed by air.Commanders found that the use ofairmobility increased the utilizationof their available troops by a factorof not less than four. By Vietnamstandards the use of airmobility inMalaya was rudimentary; but theseoperations did signify the obviousJULY 1969

advantages which airmobility hadto offer.The French u e of helicopters inthe Algerian War h raId d the advent of large- cale airmobile op

eration. he outbreak of the Algerian revolution in 1954 caughtFrance totally unprepared to fighta guerrilla war. The units whichFrance initially committed to Algeria were equipped and organizedfor conventional warfare. Theywere NATO-type forces and unable to cope with the tacticutilized by the Army of ationalLiberation ALN). The terrainand the nature of the conflictstripped the 50,000 French troopsof their normal technological superiority. The insurgent movementcontinued to grow. By 1956 theFrench trength had increased to260000 and by 1958 to 400000.

The French reorganized theirforces in 1956 to give them an improved reaction capability againstthe L Jet fighters were replaced with lower ground-supportplanes and helicopter were addedto improve the tactical mobility of

the French forces. For the firsttime in history exten ive u e wasmade of armed helicopters to provide necessary fire support for airmobile operations. The Frenchrealizing that paratroop unit werelightly equipped and well trainedfor the shock action associatedwith airmobile operation, coupledthese units with helicopter transport units to form airmobile taskforce . The mission of destroyingthe rebel unit was given to theseta k force whose total numbernever exceeded 50 000 men. Theucce s of the e tactics contributedimmea urably to reducing thetrength of the guerrilla forcesfrom a high of 40 000 to less than12000 in 1960.

There were many French innovation in the use of the helicopterduring the Algerian conflict. Theneed for an airborne command andcontrol group during large-scaleairmobile operations resulted inthe adoption of helicopter command posts. Helicopters werearmed with machinegun androckets to provide suppres ive fire

The British pioneered the use of airmobility in the defeat of communistinsurgents in Malaya from 1948-60 see Malayan Operations,DIGEST, October 1962). Below, an -51 in a jungle LZ in Malaya

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Above, the 11th Air Assault Division (T) establishes the validity of the Army sairmobile concepts in maneuvers against the 82nd Airborne Division in late1964 The 11th was quickly deployed to Vietnam as the 1st Cavalry Division(Airmobile>. I t was extremely effective as in Operation Pershing (below), asearch and destroy operation near n Khe

on the landing zones to permit thetroop-carrying helicopters to landwithout excessive losses. The Vertol CH 21 ) helicopters wereequipped with self-sealing fueltanks, and crews were providedflck vests and armored seats. TheFrench adopted a regulation whichrequired two qualified pilots on all

helicopters so that if one waswounded or killed the other couldbring the aircraft back. Thesemeasures, together with the tacticsand techniques which the Frenchdeveloped for airmobile assaults,resulted in a steadily decreasingrate of helicopter and crew lossesdue to ground fire.

The success which the Frenchachieved in combat helicopter operations in Algeria provided agreat incentive to those in theUnited States Army who were developing airmobile tactics andtechniques. Combat reports and awealth of statistical data wereanalyzed to further the airmobileconcept which was formulated in1962 by the Army Tactical Mobility Requirement Board, headed byGeneral Hamilton H. Howze. Therecommendation of the HowzeBoard for the organization of anair assault division to formally testhi bold, new concept of mobilitywas approved by the Secretary oDefense.

The first elements of the 11 thAir Assault Division T) wereactivated at Ft. Benning, Ga. , inFebruary 1963. Extensive fieldtraining was conducted to test andevaluate new items of equipmenand to standardize unit proceduresBy late summer of 1964, the fuldivision had been organized andbattalion and brigade level testinghad been accomplished.

The evaluation of the divisionwas culminated in November andDecember of 1964 when the division, supported by an air transporbrigade, was opposed by the 82ndAirborne Division in the Carolinamaneuver area. In a series of controlled exercises, the 11 th Air Assault Division was placed in everyknown tactical environmentReams of statistical data werecompiled by hundreds of umpirescontrollers and analysts. It wasfound that the helicopter, iproperly employed, was not as vulnerable to enemy fire as manyskeptics believed. Also importanin the era of co t-effectiveness considerations was the fact that theinitial and operating costs of thedivision were justified by its special capabilities not found in othedivisions.

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firmed the validity of the airmobileconcept as a bold means of improving tactical mobility on thebattlefield and led to the recommendation that an air a sault-typedivision be included in the perma-nent force structure. This recommendation wa accepted by theDepartment of Defense and theth Air Assault Division was redesignated as the] st Cavalry Division (Airmobile) on 1 July 1965.

Although airmobile operationsin Vietnam were initiated in De-cember 1961 by utilizing separatehelicopter companies to tran portRepublic of Vietnam units , andlater our own forces, the commitment of the 1st Cavalry Divisionwas significant in that it was thefirst unit specifically equipped andtrained for airmobile warfare. Theearly and rapid deployment of thisunit indicated the confidence thatthe Army and the Department ofDefense had in the capabilities ofthis unit to uccessfully fight aninsurgent war. In less than 90 daysafter reorganization, this unit arrived in the Central Highlands ofSouth Vietnam and established itsbase of operations astride Highway19 at An Kke , midway betweenPleiku and Qui Nhon. From thisbase, airmobile forces of the division effectively dominated an areaapproximately 150 miles by 150miles.

The Pleiku Campaign of October and November 1965 provided the acid test of the airmobileconcept. Regular North Vietnamese forces in division strengththreatened the seizure of Pleikuand dominance of the CentralHighland . In the battle of the IaDrang Valley, the airmobile concept was validated in combat whenforces of the ] t Cavalry Divisionmet and defeated these insurgentforces in terrain which they hadbelieved would protect them.

A brief examination of the airmobile divi ion's structure andcapabilities i approximate to high-JULY 1969

Airmobile forces c n be used in civic actions s bovewhere a CH 47 is used to ev cu te flood victims

light the suitability of this typeforce to fight an insurgent war.The 434 aircraft of the division,all but six of which are helicopters ,enable thi unit to conduct sustained combat operations independent of surface mean of communication. As helicopters are theprimary means of movementweight is a most important consideration in all operations. Lightweight equipment is utilizedwherever pos ible in lieu of theheavier type found in the infantrydivision. The equipment of allcombat and combat support unitsof the division is designed to becompatible with the capabilities ofthe organic aircraft. Only theheavier equipment found in thedivision base area is dependent onnonorganic aircraft for movement.The 1,500 wheeled vehicles in theunit are approximately one-halfthe number authorized the infantrydivision. The airmobile division's

weight of 10 000 tons is less thanone-third the weight of an infantrydivision.The airmobile division utilizes

aircraft as the primary means ofaccompli hing the five major functional ta ks of land combat: command, control and communications; intelligence; maneuver; firesupport; and logistics. Helicoptercommand posts are structured intothe units of the division to facilitate the close coordination necessary between all elements of anairmobile force. The air cavalrysquadron has the capability toscreen vast areas of terrain to findand fix the enemy. Organic aerialfire support is provided by theaerial rocket artillery battalion.Thi capability permits the initiation and conduct of operationswithout first establishing a firebase. The close-in fire supportwhich this unit provides also allows operations to be conducted

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Tactical irmobility s The nswer structured re-equipped and retrained for three-dimensional landcombat. The success of the 1stCavalry Division against regularNorth Vietnamese forces and theViet Cong should serve to assurethese countries that airmobileforces are capable of defendingagainst outright invasion as well asthe primary threat of insurgency.Our considerations for hemisphericdefense may be partially responsible for the primary orientation ofthe armed forces of some LatinAmerican countries toward repelling foreign aggression rather thandefeating internal subversion.

under conditions of low visibilitywhen tactical air upport cannotreach the objective area.The division aviation group hastwo battalions of UH 1 D lift heli

copters and one battalion of CH47 medium lift helicopters. The eunits provide 90 knot mobility forthe maneuver battalions the directsupport artillery battalions thecombat upport unit and for thelogistical resupply of all unit forward of the division ba e. Theclo e integration of these capabilities in an airmobile operationre ults in an overwhelming differential in maneuver and firepowerover any guerrilla force.The airmobile division is emphasized because its organizationand capabilities best illustrate thetype force that can provide a military answer to the threat of insurgency in developing areas of theworld. The mobility of other unitsmay be enhanced by periodic augmentation with aircraft pre entlybeing done successfully in Vietnam. This arrangement howeverdoes not achieve the full potentialwhich airmobility has to offer. This

is attained only by a force whichis structured equipped and trainedspecifically for this type of combat.Airmobility as a way of lifemust be built into the unit. Thetechniques which are necessary forthe most efficient use of the helicopter can be perfected only byrepetitive training. A clo e rapportbetween all elements of the team iessential to successful airmobileoperations. Professionalism cannot

be achieved on a part-time basis.Developing nations generallycannot afford the cost of a division-size airmobile force but a unitof this type can be tailored to anysize con i tent with the needs andresources of a particular country.Regardless of the size of the unit 8

it must include aerial vehicles asthe primary means of accomplishing the five major functions of landcombat. A platoon-size forceequipped with three armed reconnaissance helicopters and sixtroop-carrying helicopters wouldhave an airmobile capability thatwould spell doom to a much largerguerrilla band.

Developing countries that arecontemplating the purchase of jetfighters could acquire a far greaternumber of helicopters for the sameamount of money. There is littledisagreement among those experienced in insurgency operations asto which type aircraft can best carry the fight to the guerrilla.It takes time however to equipand train an airmobile force. t istoo late to think about one whenan insurgent movement has begun.The developing countries shouldhave these forces now to respondimmediately to the threat of evena handful of guerrillas. A convincing argument to justify theexistence of airmobile units in apeacetime force structure is themany ways in which the helicopters can be utilized in civic actionprograms. Airmobile units can bein trumental in nation building andeliminating the basic causes of in-urgency.

The United States must undertake an aggressive program ofelling airmobility to the developingcountries. This improved means ofbattlefield mobility is at least thepartial military answer to the perilof insurgency which threatens theirefforts to achieve peaceful evolution. We cannot assume that ourextensive use of airmobility inVietnam will suffice to convincethem that they must reorganizetheir forces to gain improved tactical mobility.

The forces which many of thesecountries now possess must be re-

f the goal of capable airmobileforces is to be attained in thethreatened areas of the world wemust actively assist in the .organization and training of these units.As a result of our operations inVietnam we have a large numberof personnel who are thoroughlyindoctrinated and experienced inthe airmobile concept. These arethe ones who as military attachesand members of military assistanceadvisory groups must lead the wayin the planning for and the organization of these forces. At lowerlevels our unit advisors will be required to assist in the training ofthese units. There is no substitutefor the know-how which these experienced personnel possess.Tactical airmobility has evolvedfrom the process of transporting afew soldiers by air from point A topoint B to the present day capability to conduct large-scale sustained airmobile operations. Further advances in technology wilfacilitate our ability to find ixand destroy guerrilla forces. To-day tactical airmobility presentsthe best solution to the problem ofbringing the full spectrum of combat power to bear on an insurgenenemy. The United States is winning the war in Vietnam with airmobility. The blueprint exists withwhich the developing countries canbuild a force to guarantee theifreedom.

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in January 1968, combatand weather conditions forcedhelico.,... pilots of the 1st Cavalry Div n (Airmobile) to flynumerous go helicopter instrument missions in the northern part of I Corps area.The IFR requirement grewout of a situation in which generally poor weather was forcing helicopters to be flown lowlevel. They were fired at andhit almost daily. In fact, to flya mission without taking hitswas are.From the evening of 31 Jan1968 to midmorning on 2 Feb1968, the Cav s 228th AviationBattalion had 11 CH-47A cargohelicopters shot up and threec;rewmembers wounded.The aircraft were attempting to move -personnel, ulpment and supplies un marginal w co Clltlons whichrequired tow level flight intoand within the division AO(area of operations). When theweather permitted, flights weremade at altitudes above 2,000to 2,500 feet. The aircraft re ceived only occasional hits butwith the rainy season in progress good weather flying dayswere few and far between.

On 28 and 29 Jan 1968pment flown into LZ Evans

nextweatherthe divisionvolved air lifting101st from HueCamp Evans andequipment from Hue PhDagmar Bravo, 15 mil of Hue Phu-Bal on . -ast.rs, flyarginalon the_ e l r Bravo.rcraft werepending an improvement the weather. Asit became .pparent the weatherwould r in poor and withthe urge cy of the missionsprevailing, it was decidedsomething different would have

to be tried if the missions wereto be completed successfully.

Althoughment flyingganic radarmet withwas nowsary for to attemptwholesale IFR flight.

In addition to the lack of anestablished proc

IFR flying in the Jeb StuartAO, there also was the question of whether the ATC sectionwould be able to handle trafficin a great enough volume tosatisfy the division requirements.contacting the ATC chiefPhu-Bai, the pilots werethere was no combetween Hue ATC

ATC The aircraftcommanders felt they could resolve this problem y contacting Hue Phu-Bal for IFR clearance and requesting radar vectors to VFR-on-top. Once on topcontact would b made withEvans ATC for radar vector andletdown to Camp .Evans.

Around noon on 2 Feb thedecision was made to launchthree helicopters to CampEvans. The three aircraft departed Hue Phu-Bai with 15minute separation. The handoff from Hue Phu-Bai ATC toEvans ATC was effected and aletdown using ASR procedureswas made since the PAR systeminoperative.landing a tcommanclerc.stant battalion 1 4the ATC sec 1 ' l I Inate and i1for IFR missions In the AO. TheEvans ATC chief Indicated hiscontrpl


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In the June issue of the AVIATION DIGEST, I introduced myself and my big brother, Danny Dash 10,and asked that any questions regarding the checklist(CL) or operators manual (dash 10) be directed tous at: Evaluation Division, Office of the Director ofInstruction, ATTN: Charlie Checklist, Ft. Rucker,Ala. 36360. During the past three weeks severalquestions have been received. Here are a few.

I HAVE BEEN reading about the DA checkliststhat are being prepared on all Army aircraft butmy unit hasn't received them as of this date. Whatis the procedure of obtaining the CLs?Charlie's answer: The checklists are distributedthrough AG distribution channels. Each unit mustsubmit its requirement to AG on DA Form 17 and17-1, Requisition for Publications and Blank Forms.Complete the forms and you will receive the checklists.My unit has received the new CL on the AH-IGand aviators are using it faithfully. One slight problem, though-it is in looseleaf form. Any suggestions on securing it for use?Charlie's answer: Yes, there is a container speciallymade for the checklist. Its official name is Operatorsand Crewmembers Checklist Binder, TM 1500-1.One TM 1500-1 binder is authorized for each aircraft and may be obtained t r o u ~ A G distributionchannels; however, users must submit requisitions inorder to receive them.On page ii of my checklist the term thru flight isassociated with an asteri k (*) symbol. What exactlydoes the term and ymbol indicate?CharHe's answer: Refer to Chapter 3 of the operators manual (dash 10) for your aircraft and youwill find the following: When the aircraft is flown bythe same flight crew during tactical or administrativemissions requiring intermediate stops, the flight crewneed not perform all the pre-flight checks requiredby the amplified or condensed checklists for beginning flights. Under these conditions, all of thestarred (*) items in these lists are required checksto assure safe operation.In the UR-IC engine runup procedure, as outlinedin the CL, Step 6 states FUEL BOOST PUMPSCHECK. What is the correct procedure for checking the boost pumps?Charlie's answer: I'll answer your question but firstJULY 1969

let me mention that the CL is a condensed form ofthe normal and emergency operating procedureschapters in the operators manual (dash 10). Formore detailed information on specific items n theCL, refer to the appropriate chapters of the dash 10.Now, your question. Step 6. FUEL BOOST PUMPSPul l LEFT FUEL BOOST circuit breaker, notecaution light on and normal fuel pressure. PullRIGHT FUEL BOOST circuit breaker, note cautionlight and fuel pressure reading of o After 10seconds, LEFT FUEL BOOST circuit breaker in,note CAUTION LIGHTS out and fuel pressure returning to normal. RIGHT FUEL BOOST circuitbreaker in, all caution lights out.I have been flying the U-21 here in the Republic ofVietnam for nine months and there are some itemsin the new CL which appear to me to be out ofsequence. I have documented my proposed changes;now what do I do with them?Charlie's answer: Youare encouraged to listyour proposed changesto the CL and operators manual on DAForm 2028 (Recommended Changes toDA Publications) andforward them directlyto: Commanding General, U. S Army Avi-ation Systems Command, ATTN: AMSAV-M, P. O.Box 209, St. Louis, Mo. 63166. Your proposedchanges will be evaluated along with other suggestedimprovements and, if adopted, published as a changeto the checklist. These checklists are published forthe pilot and you aviators are best qualified to suggest improvements, so don't hesitate to submit yourrerommended changes.


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The Chinook climbs slowly until it cle rs mount in peaks and cloud layersimum of five IFR aircraft at onetime. A procedure for 1 t communications was established using theEvans NDB for a figure eight approach on the 360 degree axis.

Due to limited storage refueling in the AO was done at HuePhu-Bai and Camp Evans on anemergency basis only. The mainrefueling wa done at DagmarBravo. A route and procedure forDagmar Bravo was agreed on butwithout an approach fix there theproblem of making an approachexisted.The ATC chief indicated Dag

mar Bravo could be plotted on hisradar cope and aircraft could bevectored to this point and an approach made using ASR procedures. This procedure was agreedon by the aircraft commanders andwithin the hour aircraft were taking off from Camp Evans to test

the new routes and procedures.The flights went smoothly and withminor modification the procedurewas considered adequate to accomplish the mission.CH 47 As began airlifting personnel equipment and suppliesfrom Da Nang and Hue Phu-Bainto and within the AO under allbut the most hazardous of weatherconditions. The aircraft were ableto climb to a safe altitude andenemy hits were greatly diminished.

The rou te and proced ure for thoseaircraft departing Da Nang toCamp Evans involved VFR lowlevel flight along the coast keepingfar enough out to sea to avoidenemy fire. They refueled at Dagmar Bravo and contacted EvansATC for IFR clearance into Evans.Flights from Hue Phu-Bai toEvans due to the lack of communication between ATC sectionswere required to climb to VFR-on-

top then establish communicationwith Evans ATC for clearance anradar letdown to Evans.Since the cloud tops were sometimes higher than the heavilyloaded helicopters could fly thproblem of hand off from Hue tEvans presented a problem. t warectified by having the aircracommunicate with Hue Phu-BATC on UHF and Evans ATC oPM in flight thereby coordinatintheir own hand off.Helicopter flights IFR were usually conducted between 2000 an3000 feet while fixed wing aicraft operated at much higher alttudes thus maintaining adequatseparation in the AO.During the month of Februarpilots of the 228th flew more tha700 hours in weather making hundreds of approaches without incdent. As a result of the successfuprocedure to locate and approac

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Dagmar Bravo, the same procedurewas u ed to resupply remote LZs.Mi sions involving external slingload under IFR conditions, although still in the infant stage,were tarting to grow. As the weekpassed, more and more pilots werebecoming receptive to the idea of

attempting IFR flights carrying external loads. More than 20 missions involving sling loads IFRwere successfully completed withonly three sling loads intentionallyreleased during flight due to severeoscillation. Pilots who had previou ly experimented with sling loadson hooded flights , completed theseactual missions successfully.The problems overcome duringthis period and the experiencegained were to prove very valuable

to the 1st Cavalry Division duringthe April 1968 assault into theA hau Valley in Operation Delaware. Aviators holding only Tactical In trument Ticket , whengiven upplemental unit instrumenttraining, were found capable ofperforming IFR sling load missions, even when paired together inthe aircraft, which happened onmany occa ions.On the morning of 19 April 1968Operation Delaware launched

the initial assault into the AshauValley. Forecast weather for theweek indicated clear to partlycloudy skies in the early morning,becoming broken to overcast during early afternoon. Rapidly building towering cumulus clouds andthunderstorms were forecast in themountain regions throughout theafternoon and early evening, gradually dissipating during the night.The terrain between Camp Evansand Ashau Valley tart ju t above

sea level at Camp Evans remaining level for several miles,rising rapidly to more than 5,feet in the mountains adjacent tothe valley, then dropping sharplyto the valley floor some 3,000 feetbelow. The valley is long and narrow, running southeast to north-JULY ]969

west for approximately 27 milesalong the Laotian Border.The area of operation from LZTiger in the northwest part of thevalley to LZ Lillian in the southeast averaged slightly more than amile in width.By mid-morning the routes to

the valley saw heavily laden cargohelicopter , some loaded internally,some with sling loads of ammunition or a 105 howitzer, slowlyclimbing for altitude that wouldclear the mountain peaks andlower cloud layers. The aircraftusing radar monitored climbs toVFR conditions-on-top, would descend through holes in the cloudlayer to LZs in the valley. Returning to Camp Evans the helicopterswould contact Evans GCA forapproaches.Weather continued to be a majorproblem each day and though planswere underway to set up a GCAsection and NDB in the valley ssoon s the Aloui airstrip could betaken and secured, it would beanother week before this wa tohappen. Then it was found inadequate to atisfy division requirements, due to its location and type

equipment. Throughout the AshauValley operation, Evans GCA wasindi pensable in providing radarvectors to and from the valley,traffic separation and GCA approaches to Evans.Although handicapped with inadequate equipment and maintenance problems, the GCA section'sperformance was nothing short ofmagnificent. Its instant responsivene s was a tremendous morale factor , especially to those crews returning with wounded aboard, aircraft shot up or dangerously lowon fuel.As the weeks progressed, morethan 20 aircraft were being simultaneously controlled or monitoredby radar to and from the valley.Handling of inflight emergenciesbecame routine. By 27 AprilOperation Delaware progressedsou thea t to secure Aloui airstrip.A nondirectional beacon and amobile ATC unit were flown in.

The section was operational thenext morning, but due to poorweather a flight check to determineits accuracy could not be conducted. Reports from the valleyindicated weather had closed pre-A radar monitored climb to VFR on top is m de

13


16/68

HINOOKS

without cargo helicopter IFR flights, the success of OperationDelaware may have been more costlyviously existing holes in the cloudlayer. Ammunition was badlyneeded by some of the units whowere in contact.

n aircraft was launched and thecrew was asked to take a look atthe valley to see if they could getin. A radar monitored climb fromEvans to VFR-on-top and a vectorto the valley was made. On reaching the valley it was found coveredwith a solid overcast. The GC atAloui was contacted and an approach to Aloui was completed.Within the coming weeks anduntil Opera tion Delaware wascompleted on 15 May, numerousIFR flights were made by cargohelicopters to and from the valley.t is highly conceivable to conclude

that without an IFR cargo helicopter capability, the success ofOperation Delaware could havebeen more costly.In discussions prior to and during Operation Delaware manyaviators felt cargo helicopter IFRflights in a combat environment

were not only practical but in somecases highly desirable. This beingtrue the need for better equipment,both ground and airborne, is amu t.Ground equipment should include radar with moving targetidentifiers in order to locate andtrack aircraft flying in areas ofprecipitation, locate thunderstormsand vector aircraft around them.

Radar equipment should have increased quality and range to satisfymission requirements in the AO.t least two nondirectional beacons of a high quality with individual power source and a back-uppower source should be widelyseparated at division base. Generator failure, or a well-placed enemy

mortar or rocket could spell trouble with only one beacon in use asis the present case.The ATC section personnelshould be better trained to operateand maintain their equipment inorder to fulfill their responsibility.Aircraft should be equipped with

airborne radar, a better qualitytransponder (the present transponder in use is a W orId War Ihand-me-down), Doppler navigation equipment, an absolute altimeter and Tacan. This equipment isand has been available for procurement off-the-shelf for some timeIt is necessary that the aircrafbe maintained in a continuous mission ready status; therefore it ishighly desirable that on-boarnavigation equipment be self -contained when possible. In the chronological advancement of cargohelicopter combat instrument fiying in the 1st Cavalry Divisiona peak in efficient operation wareached during Operation Delaware. But in June 1968 a turnover of TC personnel resulted in

an experience void requiring considerable in-country training. Newinadequately trained controllerduring practice instrument fiyingunder VFR conditions, frequentlyissued incorrect clearances andgenerally demonstrated a lack ounderstanding of TC proceduresThe need for an IFR combacapability was demonstrated during the Ashau Valley campaignAs a result, an intensive instrumentraining program was initiated in

the division at unit level in ordeto widen the present experienclevel of instrument flying and tomaintain an IFR capability.t was found highly desirable tohave at least one instrument examiner and one school trained instrument IP in each helicopter company for a continuing instrumentraining or refresher-type program

n improved IFR capability wilalso enhance the night capabilityWith continued emphasis on training of aviators and TC and electronics personnel, the optimum inexperienced personnel will be availble. With the added ingredient obetter ground and airborne equipment, a state of total flexibility maythen become an integral part of theairmobile division.

14 U. S RMY VI TION DIGEST


17/68

aintenancev

Operationspl n th t worked

Before the new plan, this company smaintenance personnel could only workt two speeds-wide open or stopped

Lieutenant Colonel Thomas W. Wheat

JULY 1969

PRIOR TO A new plan to dovetail operations andmaintenance efforts, the maintenance personnelof the 174th Aviation Company AML) operated atthe same two speeds as a Volkswagen on the Autobahn wide open or stopped. Helicopter availabilityvaried from 10 one day to 16 the next. Periodicscame due three or four a day every four or five days.The operations officer would be short aircraft oneday and over the next. Things were not going toosmoothly.A plan was devised to help integrate the maintenance and operations efforts and smooth out theavailability peaks and valleys. The plan worked. ta graph of hours to periodic inspection plottedagainst sequence number to inspection. The planwas in the form of a 8 by 10lh inch paper, plottedwith 2 horizontal lines and 28 vertical lines. Thehorizontal lines represented 100 flying hours andwere labeled on the right side from top to bottom,100 to 0 in five-hour increments. The vertical linesrepresented the sequence number to periodic inspection PE) and were labeled across the bottom, rightto left, 0 to 18 followed by 0 to 8. This allowed thegunships to be kept separate from the slicks, sincethey fly at different average rates; while it alsoallowed the aircraft to be shown on the same graphas they had to be spaced into the slick periodicworkload.

The 75th, 50th and 25th lines represented intermediate inspection PMI) points and were underlined. Aircraft records were inspected to obtain thehours remaining to PE on each aircraft by tailnumber and arranged them in sequence. Then eachaircraft was plotted where the hours remaining intersected its sequence number and the tail number wasindicated by that dot. A line was drawn from thelower right corner to the highest dot representing aflyable slick. The same thing was done for the gunships. This gives an exact picture of the spacing ofthe ships.I f all the dots fell on the reference line, thingswould be perfect. The dots frequently missed. I f aship was very far removed above the line, it wasassigned a heavy mission for the next day. If it wasvery far below the line, it was given a low-timemission.All three platoon leaders owned their aircraft andcrews. The gun platoon leader had his own graphand was solely responsible for his ships. The twoslick platoon leaders assigned missions to their shipsand crews. They worked together to keep their shipsnear the reference line. Occasionally they traded missions in order to move ships toward the line. Thegraph was constructed nightly after the shipswere back in. When the graph showed aircraft

5


18/68

Maintenance vs Operationsbunching up, the company commander held a scheduling conference. The next day s graph usuallyindicated improvement.

The maintenance officer becameecstatic. He could forecast maintenance requirements and work hiscrews efficiently. f a problem wasdeveloping, he could see it farenough ahead to do somethingabout it. Since his clerk constructedthe graph, the maintenance officergot the first look at it. He would

make notes by a particular ship forthe benefit of the platoon leaders.FLY HOLD, FLY TO PE andNOT TO PE were his most oftenused notes.

The 75th, 50th and 25th-hourlines indicated which ships werecoming into intermediate. Themaintenance officer may want topull a ship the night before in order to keep it from coming downafter a short flight the next day.The ships were normally pulled

three hours early if they weneeded.As a matter of routine, intemediate inspections and periodiwere not overflown. As a resuof this and an extremely capabmaintenance officer, the companmaintained high availability anhigh utilization. In August 3,20flying hours were recorded. On 1September, the company had 10percent availability after havinflown 6,300 hours the previous 6days.There were other program

Helicopter Availability Chart

557X 647X 555X 080XII II II II II ~ 6 4 26 25 24 23 22 21 20 19~ ~ 6 4 1~~ 640C: ~ ~~ II ~39[~ 1 0 6 0 ~ 6 X

~~ H

~137 ~~

I

~ I,426 ] ~ Ii: 429X165I ~ ~

~138 F L Y TO PE. 1-

I

-I~ 209 I

i ~203l

I ~ \ ~mr II

DATE TOMORROW)II

.'II,

,II I

I n II n ulII

I i872 , I] ] 911 FLY ul~ [] 91UO FLY IIII ~ i~ ~ I II]888~ ~ 906

~ ~ 193 FLY~ ~

~ I NOTHOLD 621 1 ~ T O PE867

m ~IIFLY TO PE 983[ ~

100 PE95908580~ P M7656055~ P M45403530

~ PMI2015105

8 7 6 5 4 3 2 1 0 18 17 16 15 14 13 12 1 9 8 7 6 5 4 3 2 1 0GUNSHIPS SLICKS

16 U. S ARMY AVIATION DIGES


19/68

which contributed to this availability. Every time an aircraft wasshut down, a postflight inspectionwas performed. Woe be to the aircraft commander who parked onefor the riight and had overlookedsomething that kept it from meeting its scheduled take-off time. thenext morning. There are somethings that can go wrong overnight;but bearings do not get loose androtor blades do not hit I j m ~ s Ihisprogram kept surprises from ruining the morning departure schedule-.We heads, intake and exhaustwere also covered.

Our ships were relatively hightime aircraft. We took our share ofhits. t took a lot of effort to keepthe availability high. This one simple management plan helped morethan anything else. The more itwas used, the more information itgave. The chart could work foranyone who flies more than approximately six aircraft.

There were usually four aircraftin for PE and they usually tookfour days to pull. The plan calledfor one in and one out every day.There was a lot of night maintenance performed too. The periodics were usually performed duringdaylight by the day crews. Theywere less likely to overlook something in daylight than at night.Later on, the platoon leader assigned an aircraft commander toeach ship and it was his. This alsowas a tremendous boost to theoveral1 effort. The major problemhere is that one cannot fly as much,daily, as can the a i r c r ~ f t t becamenecessary to put other people inhis seat just to keep him fromwearing himself out. When the aircraft commander would be out onthe:-ramp,helping the crewchief pullthe. inteJ)mediate at midnight, youcan fig e the state of morale.

Inspections were as thorough asthey were regular. The aircraftwere not down for unscheduledmaintenance very often. This is abenefit of regular and thoroughJULY 1969

maintenance. Occasionally a shipwould not come out of inspectionbecause of something ususual.There was one intermediate thattook eight days. A vibration in theaircraft, that defied detection, wasfinally found in the ,swashplate.The chart shown is an actual

chart adapted to show all the situations which could possibly arise.The lower right corner is wherethe slicks slide from service toperiodic and this is where the chartpays dividends. Aircraft number983 is only three hours out of PE.The next ship, 867, has 12 hoursremaining. With a light missiontomorrow, it can be held off. By100kiI1g left to the gunship line,

Woe be to the aircraft com-mander who parked his birdfor the night and had over-looked something that keptit from meeting its sched-uled takeoff time the nextmorning There are somethings that can go wrongovernight; but bearings donot get loose and rotorblades do not hit limbs

138 is only five hours out. Byscheduling it on the primary team,it will go into PE tomorrow too.This will mean that only two shipscome down for PE tomorrow. Alight schedule tomorrow is alsoneeded for 621 which is crowding867 a little too closely. Aircraft193 is in for intermediate tonightand can use a heavy flight since itis displaced vertically above thereference line. The maintenanceship is 906 and is controlled exclusively by the maintenance officer. Aircraft 888 is okay but 910,just out of PMI, needs a heavyschedule to obtain proper spacingand return to the reference line.Aircraft 911, 872 and 863 were

placed here to illustrate a specialproblem-they are all within 2hours of PM . About noon tomorrow they would all come downtogether. However, the night crewswill be busy getting these shipsthrough PMI tonight, enablingtheir use all day tomorrow insteadof half a day.A second problem is indicatedby the spacing between 910 and864. Five ships arewithin a 10-hour block which means that spacing must be improved or five shipscould come down for PE in oneday. This must be avoided. Thereis good spacing between 864 and203 but both are below the line.With a couple of days of light orless than heavy scheduling, theyshould move up to the line. Aircraft 209 is no problem. Aircraft016 is down for unscheduled maintenance combat damage or accidental damage. Tomorrow 639 willprobably by-pass 016 as 639 isonly two hours from PMI-another night job for maintenance .There is no problem when shipspass each other; the scheduling iscontinued so that each dot movestoward the reference line. Aircraft641 and 642 are just out of PEand should be flyable for approximately 12 days, when their nextPE will be due. At the present,080, 555 and 647 are in PE andshould come out one a day for thenext three days.

The gunship line shows an almost perfect situation. Aircraft138 goes into PE tomorrow andwith luck, 557 comes out; 429 isdown for bullet holes and will beout in one to two days. This spacing is indicative of a good gunplatoon leader in that he schedulesall gunships.There is no way to separate themaintenance effort from operations. Operations makes maintenance necessary. Maintenancemakes operations possible. Thesolution is to more closely integrate the two.

17


20/68

anti tolq e /Je 1 IUas?

Do You Really Know The UH l?aptain harles Nolan and aptain Henry Roll

THE MAJORITY of rotarywing rated aviators in today sUnited States Army are well awareof the capabilities and record ofthe UH-l helicopter. Introduced asan aircraft ideally suited for medi-cal evacuation duties in the late50s, the UH-l is now the backboneof the Army s fleet of rotary wingaircraft. Not only did the UH-lfulfill its original intended mission,but through the efforts and fore-sight of many dedicated individ-uals, the Huey began to serve18

as a weapons platform, a trooptransport aircraft and a commandand control center. The number ofmissions that the UH-l performstoday are almost infinite.However, an aircraft is only asdependable as the people whomaintain it and the aviators whofly it.Since maintenance is an aspectof aviation where the aviator islargely dependent on the skills andprofessionalism of others, this arti-cle will not cover any maintenance

problem beyond the scope of theOperators Handbook ( dash 10)Of course, an aviator can preflighhis aircraft and it is to his benefito learn as much about it as hepossibly .can, but it is still the re-sponsibility of another to place theproper torque on a critical boltThis is the responsibility of sup-porting maintenance and a factorover which the average aviator hasno control.However the aviator has theportant responsibility to know the



21/68

n ircr ft is only as depend bleas the people who m int in it

nd the vi tors who fly itcapabilities and limitations of hisaircraft under all conditions. Onlywhen the aviator matches his owncapabilities with those of his aircraft can he continually achievemission effectiveness.The following section of thisarticle consists of a test which willallow you to evaluate your knowledge of your aircraft. Like all tests,it cannot cover everything but webelieve that it does an adequatejob. t is not intended that the testget into specifics for which theaviator has to search his operatorsmanual, but if you find yourselfdoing just that it may indicate thatyour knowledge of the UH-l is notwhat it should be. The majority ofquestions concern informationwhich is applicable to all models.A few questions do concern a particular model, but these are considered important enough to beknown by all UH-l rated aviators.All that is left to do now is totry your skill. f you know youraircraft, the test is extremely easy.f not, well, you be your ownjudge. Good luck

Multiple hoice( 1) On UH 1 aircraft equippedwith a fuel filter caution light,should its illumination occur:

a) flight may be continued not toexceed 30 minutes, b) the aircraftshould be landed immediately,c) the fuel bypass line will openand the aircraft may be flown until the next intermediate inspection,d) the fuel filter will continue tooperate but the occurrence shouldbe entered in the 2408-13.JULY 1969

2) The UH 1 aircraft may usethe following fuel s) whenequipped with the T53-L-13 engine: a) IP-4, b) IP-5, c) ordinary gasoline, d) A and B, e) A,Band C.(3) As fuel is consumed duringflight the center of gravity of theUH ID will: a) move aft, b) moveforward, c) remain unchangedsince the fuel cells are located directly beneath the rotor mast,d) move upward.(4) Rapid and abrupt movement of the cyclic controls of aUH-l may possibly cause: a) anervous copilot, b) extreme wearon all stabilizer bar components,c) a check valve in the hydraulicirreversible valve to become unseated resulting in control lock-up,d) a reduction in transverse floweffect.(5) The proper emergency procedure in the event of a tail rotormalfunction in the UH 1 (inflight)would be: a) immediately executea normal approach compensatingfor torque movement about theyaw axis with manual throttle control, b) execute a running landingas soon as possible, c) execute anautorotative landing as soon aspossible, d) either B or C may bethe correct solution depending onthe type of malfunction.

( 6 ) In the event of completeboost pump failure, the enginedriven fuel pump in all UH-ls iscapable of supplying engine fuelrequirements: a) at pressure altitudes of less than 5,000 feet, b)at pressure altitudes of less than4,600 feet, c) at density altitudesof less than 5,000 feet, d at density

altitudes of less than 4,600 feet.7) Based on the fact that theload factor on the main rotor system in level flight is equal to oneG or the weight of the helicopter,a stabilized turn with 60 degreesof bank: a) will double the loadfactor on the main rotor system(two Gs), b) will not increase theload factor if the rate of bank isheld constant, c) load factor is nota consideration in UH-l helicopters, d) both Band C.

8) Maximum allowable rotorrpm in autorotation for the UH-ICand D is: a) 341 rpm, b) 329rpm, c) 339 rpm, d) 349 rpm.9) Retreating blade stall in the

UH-l is most likely to occur: a)at high airspeed and high rotorrpm, b) high airspeed and lowrotor rpm, c) low airspeed andhigh rotor rpm, d) never becauseretreating blade stalls are virtuallyeliminated by the damping actionof the stabilizer bar assembly.

10) The recommended turbulence penetration airspeed in allUH-l models is: a) 60 knots,b) 80 knots, c) 45 knots, d) 70knots.( 11) Assuming a normal center of gravity loading, loss of thesynchronized elevator on UH-lhelicopters will result: a) a tuckunder tendency of the aircraft noseat higher airspeeds, b) a tuckunder tendency of the aircraft noseat lower airspeeds, c) no changein aircraft pitch attitude, d) complete loss of control.( 12) The low rpm audio signal is considered operational within limits if it is heard at: a) 28510 rotor rpm, b) 295 10 rotor

9


22/68

rpm, c) 310 5 rotor rpm, d)315 5 rotor rpm.( 13) Maximum allowable EGTduring start in the UH-IC and Dmodels equipped with the L-llengine is: a) 675 degrees C,b) 760 degrees C, c) 740 degreesC, d) 650 degrees C.( 14) How soon after power isapplied to its circuits does thepilot's artificial horizon gyro become reliable? a) immediately,

b) in three minutes, c) in twominutes, d) in five minutes.( 15) The recommended cruiseairspeed for the UH 1 C and Dmodels during instrument flight is:a) 70 knots, b) 75 knots, c) 80knots, d) 85 knots.( 16) Floor loading in the UHID shall not exceed: a) 250,b) 175, c) 150, d) 300 poundsper square foot maximum packagesize and gross weight limits.17) In the UH-IC, equippedwith the collective accumulator,when the HYD control switch ismoved from BOTH (center) position to SYS 1 on position, theno. 2 hydraulic system is disabled.In this situation, the: a) antitorque pedals, b) armament, c)horizontal stabilizer, d) collectivepitch, hydraulic system will be ren-dered inoperative.18) In the UH-1B, C and Dmodels when the rpm increase/ decrease switch is activated to fullincrease, the engine rpm shouldstabilize at: a) 6600 50, b)6700, c) 6700 50, d) 6650rpm.

True and False19) The UH-IC, D, Band Hmodels are equipped to operate in

forecast moderate icing conditions.20) The handling qualities ofthe UH-1 helicopter at speeds lessthan 60 knots are not consideredcompatible with instrument flying.21) The UH-1 series of aircraft requires no special loadingpreparation.20

22) A fuel pressure indicationof 5 psi is acceptable for continuous operation in all UH-l helicopters.nswers

1) a) TM 55-1520-210-10/220-10/219-10, Chapter-22) e) However when an al-ternate fuel is used a write-up isrequired in the 2408-13. TM55-1520-210-10/220-10/ 219-10/218-10, Chapter 23) b) TM 55-1520-219-10,Chapter 7, figure 7-64) c) TM 55-1520-210-10/

220-10/219-10/218-10, Chapter45) d) TM 55-1520-210-10/

220-10/219-10/ 218-10, Chapter46) b) TM 55-1520-210-10/218-10, Chapter 47) a) TM 55-1520-210-10/220-10/ 219-10/218-10, Chapter88) c) TM 55-1520-210(220)-10, Chapter 79) b) TM 55-1520-210-10/

220-10/219-10/218-10, Chapter8 (10) b) TM 55-1520-210(220)-10/219-10/ 218-10, Chapter 10(11) a) TM 55-1520-210-10/220-10/ 219-10/ 218-10, Chapter 2(12) b) TM 55-1520-210-10/220-10/219-10/218-10, Chapter2; 300 5 is the dash 10 answer,therefore, b) is closest and is alsothe range taught at USAA VNS.(13) b) TM 55-1520-210-10/220-10/219-10/218-10, Chapter3. Note, however, that exceeding650 degrees C for five seconds during a start requires a hot end inspection.(14) c) TM 55-1520-210-10/220-10/219-10/ 218-10, Chapter

(15) c) TM 55-1520-210(220)-10, Chapter 10(16) d) TM 55-1520-220-10,Chapter 13

(17) b) TM 55-1520-220-10Chapter 3(18) c) TM 55-1520-210-10/220-10, Chapter 319) False. Equipped for onlylight icing conditions, TM 55-1520210-10/220-10/219-10, Chapte10

21) True. The loading procedure consists of placing the heaviest items to be loaded as far aft aspossible. Such placement locatesthe cargo nearer the helicopter center of gravity and allows maximumcargo load to be transported, aswell as maintaining the helicoptewithin safe operating limits forflight. TM 55-1520-210-10/220-10/219-10/218-10, Chapter 1322) True. TM 55-1520-(alseries) 1 0, Chapter 7

Add up your number of correcanswers and refer to the followingtable to see how you scored.18-22 Correct-Excellent10-18 Correct-Good5-10 Correct-Average0-5 Correct-PoorAlthough you might have foundthe test to be a little too specificfamiliarity with the finer points ofthe UH-1 aircraft could very easilyhelp you to avoid a dangeroussituation. The UH-1 is a sophisti

cated and demanding machine. AnArms and Legs Pilot has nobusiness in the cockpit of the Hueyas the physical manipulation of thecontrols is only a part of the overall picture. The very nature of theUH 1 mission is such as to frequently lead the aviator to ignorethe necessity for comprehensiveflight planning and maintenanceof a high level of technical proficiency. Instead the aviator istempted to just kick the tireand light the fire.The dash 10 for the UH-l ijust what its title says: an Operators Handbook, not merely aflight school study aid or a duscollector in your unit's file. Readit, study it and know it. It's thekey to safety and proficiency.

U. S. ARMY AVIATION DIGEST


23/68

VFR continued from page 1speed (V3). At normal operating rpmthen, a slight reduction in rotor speedwill result in a proportionally greaterreduction in profile drag than in induced drag and thrust. Naturally, witha reduction in profile drag there will bea corresponding decrease in the powerrequired to overcome it. This extrapower can then be used to overcomeinduced drag and produce more thrustfrom the rotor.A more graphic illustration of thisphenomenon can be seen by hovering aless-than-fully-loaded UH-l with theengine .and rotor rpm set at variousspeeds. t will be noted that the lowerthe rotor rpm, the less torque and gasproducer rpm will be required tosustain the hover. This does not mean,however, that we have increased thetotal lift capability of the helicoptersimply by setting a lower rotor rpmwith the beep switch," as some aviators believe. To understand this apparently ambiguous statement, one mustfirst have a basic understanding of theoperation of the fuel control unit onthe gas turbine engine.

The primary function of the fuelcontrol on the T53 engine is to regulate gas producer speed. t does this byincreasing or decreasing the amount offuel delivered to the combustion chamber of the engine. t will also maintaina set speed on the power turbine, withinlimits, by changing the gas producerspeed to meet the demands of the powerturbine. f the pilot has told the fuelcontrol to maintain 6600 rpm on thepower output shaft of the engine, thenchanges the load on the engine by applying collective pitch, the fuel controlwill sense this increased load and supply more fuel to the engine.

Note, however, that we said ''withinlimits." This also should apply to grossweight Once the gas producer turbinehas reached a certain predeterminedspeed (max N 1) no more fuel will besupplied, regardless of what happens tothe rpm of the power output shaft. fthe pilot increases the application ofcollective pitch, the engine and rotorrpm will decrease, because the Nt turbine will refuse to meet the additionaldemand placed on it. (As noted byMAJ Christensen in his article, the reduction in engine rpm will also cause acorresponding reduction in shaft horsepower (SHP) produced by the T53-L-ll

JULY 1969

engine.) Under these conditions, thefuel control is ignoring any instructionsit receives from the power turbine, andwill continue to do so until N2 speed isincreased back within the governedrange.Applying what has been said to thesituation posed in MAJ Common's letter, let us assume that a pilot is attempting to hover a fully (over max gross)loaded UH-l. With the engine rpm setat 6600, collective pitch is applied untilmax Nt is reached, and the helicopterwill not hover. Still more pitch is applied, and the engine (and rotor) rpmis reduced, let's say to 6400 rpm. Nowless power is required to overcome profile drag, this extra power is used toovercome induced drag, and, despitethe attendant loss in engine SHP, thehelicopter lifts off the ground.

The same results would be realizedif the pilot had intentionally reducedhis engine rpm to 6400 with the "beepswitch" prior to attempting to hover.The combination of Nt speed, N2 speed,induced and profile drag, and thrustwould be identical to that posed in theprevious situation. The only differencewould be in the method used to arriveat these results.

It goes without saying that operatingthe UH-l, or any helicopter, below theprescribed rotor rpm entails certainrisks. It is not our intent to justify thispractice. Too many aviators havefound, to their dismay, that the extralift gained in this manner is not enoughto get the job done. Bleeding down therpm is poor procedure and can result inoperation over max gross weight ordeterioration of rpm below that necessary for sustained flight.

The above d i s u ~ i o n has ignoredmany areas which could properly beapplied to the subject, such as directional control problems, transition fromhovering to forward flight, effects onair density from prolonged hovering,rotor momentum, etc.-The Editors

* rom Bell Helicopter

The U. S. Army Model OH-58A willcarry the nickname Kiowa, officials ofTextron's Bell Helicopter have beeninformed.

The OH-58A is the Army's versionof the Bell Model 206A JetRanger.Last March it was named winner ofthe Army's re-opened light observationhelicopter (LOH) competition and Bellwas awarded a contract for 2,200 ofthe five-place, turbine-powered aircraft.

2


24/68

W'ANTEDI N S T R V M E N r E X M IN E R S

Maior William H. ardner

Reward: Plenty of long hours, extra duty and additional responsibil-ities. Although no extra pay is offered, instrument examiners enjoythe prestige of being the best instrument qualified aviators in theArmy. Other rewards include ha.ving the following honoray aliases:Old Man's Pilot, Weather Missions Officer, HSafety Officer

and HStandardization Officer.


25/68

HE UNITED STATES ArmyAviation School (USAAVNS)at Ft. Rucker, Ala. , is the basefrom which all the standards forinstrument flying for Army aviation are established . The doctrineand lessoris learned at USAAVNSare carried to the field by the instrument examiners who graduatefrom the course at the school.Therefore, the instruction presented and training conducted inthe examiner courses is worldoriented and s,tudent-centered. Theobjective of the examiner coursesis directed toward teaching eachindividual examiner the skill andknowledge necessary to maintainthe high standards of the Armyinstrument program.

To accomplish these goals, theinstruction reflects not only approved procedures and doctrinesbut also demands of the students,the highest degree of professionalcompetence, tact and judgment.The examiner program remairisoriented to the concept that itsproduct will, in turn, exert considerable influence upon the Army'sinstrument flying program.

An examiner not only awards orwithdraws an aviator's instrumentrating but also administers the Annual Written Examination. Hemust willingly accept, if not seek,additional responsibilities with regard to the establishment andmaintenance of the instrument program within his unit. Finally, hemust be prepared to assist the commander, upon request, in suchareas as standardization, operations and safety.

The philosophy of an individualexaminer then must be to presentto each aviator with whom hecomes in contact, the currentstandard policies, procedures anddoctrine with regard to all aspectsof instrument flying. In additionhe must give a realistic presentation of the tasks required and sufficient assistance in attaining thenecessary proficiency. He verifiesJULY 1969

this proficiency through examinations, both written or oral , andprofessionally conducted checkrides. Adherence to these principles and standards has resulted inexaminers who best representUSAAVNS and the Army's instrument program.Unfortunately, today, t h r ~ areseveral problems throughout Armyaviation with regard to examinersand consequently the Army's instrument program. One of theseproblems is the shortage of examiners ,in many areas of the world.The current number of rotary wingexaminers, in particular, doesn'teven come close to meeting the requirements generated by the spectacular increases in rotary wingaviators since 1966. The majority

of these aviators graduated fromflight school with tactical instrument ratings. This problem of ashortage of examiners is not justone of numbers available.The majority of examiners inthe system now are field grade officers with duties and responsibilities precluding them from beinganything but occasional examiners.Of those military examiners remaining, many of the senior warrant officer examiners will beginattending the first or subsequentclasses of the newly formed Warrant Officer Career Program commencing in mid-1969. This willfurther reduce the number of examiners in the field. In addition,many other experienced examinersno longer attempt to remain current due to the press of their otherduties. To emphasize this point, inJanuary 1969, 170 examiners wereappointed to the Instrument FlightQualification Board at USAA VNS.Of these, 67 were field grade officers and 71 Department of the 'Army civilians. Of the 32 remaining, 5 were company grade officersand 27 were warrant officers. Putting these figures another way, thatof the military examiners on thisboard (many of whom give less

than five checkrides per year) ,only five in 99 or 5 percent werecompany grade officers and 25 in99 or roughly 25 percent werewarrants and the remaining 70 percent field grade. There are otherexaminers at USAAVNS who werenot appointed to the board becausethey have been unable to getcurrent.

The obvious question raised bythe above is , Why can't the Armyqualify more examiners-particularly from among its junior officersand warrants?The increased promotion rate isone reason why there is a shortage of examiners among companygrade officers as many becomequalified examiners while they arecaptains only to be promoted before their training can be fullyutilized.Another reason, and more m-portant, the course prerequisites asestablished were difficult to meet,again particularly in rotary wing,because of the Vietnam War whichhas restricted most aviators' exposure to instrument flying and thefact that almost all of the newrotary wing aviators since late1965 were awarded tactical instrument ratings. The shortage of rotary wing examiners is far moreserious than fixed wing. Part ofthe blame for this deficiency mustrest with the unit commander.Paragraph 2a, AR 95-63 states:An objective of the Departmentof the Army is to require instrument qualification of all aviators.Major overseas and zone of interior (ZI) Army commanders

(NOTE: t has been proposedthat the revised AR 95-63 read'commanders authorized to awardand revoke instrument ratings )will establish and conduct a thorough and continuing instrumenttraining program utilizing availableliterature, equipment and guidesprovided by the Army AviationSchool or higher authority and

23


26/68

WANTED Instrument xaminersavailable within the command.This program will insure that am-ple time and facilities are madeavailable to permit aviators to at-tain and maintain the degree ofinstrument flight proficiency re-quired for issue and retention ofan instrument rating. f this is theArmy's policy, then there has beena definite lack of emphasis in manyunits and at many installations onflying instruments and on instru-ment flying.There is an important distinc-tion here. Flying instrumentsmeans the ability to fly on thegauges and instrument flying im-plies knowledge of procedures andregulations. t is quite possible tobe current and proficient in onearea and not the other. This lackof emphasis coupled with the spe-cial considerations generated bythe war in Vietnam (e.g., lack ofaircraft, limited exposure to in-strument flying, etc.) and the tac-tical instrument background have

reduced the general instrumentproficiency level of rotary wingpilots in the field Admittedly,some units have had no choicewith regard to the instrument pro-ficiency of their aviators. Whenyour aviators fly 125 combat hoursa month, fatigue, the flying hourprogram and common sense llcombine to eliminate any kind ofan instrument proficiency flyingprogram in a unit. However, manyunits make no effort to have their 'pilots fly under the hood on ferryor related missions, when the pro-visions of the appropriate regula-tion could be met.

With so many rotary wing avia-tors with a tactical instrumentbackground going directly to Viet-nam, it is no surprise that mostreturn with little or no instrumentproficiency. What is surprising andunfortunate is the fact that mostr ~ t u r remembering little of whatthey were taught with regard toinstrument flying. This is the fault

he instrument ex miner must seek ddition l responsibilities in es-t blishing and m int ining the instrument progr m within his unit

of many unit commanders who dnot take the time, oft n availableto keep their aviators current onthe many changes and developments in instrument flying througbsome type of periodic groundschool. This is especially importanin Vietnam where the tactical situation has precluded the administration of the Annual WritteExamination for the past few yearsAs stated, there are just noenough rotary wing rated compangrade and warrant officers in thfield with anywhere near the prerequisites desired for the examinecourses. As early as spring 1968many examiner students begaarriving at the Aviation Schoowith waivers for many of thesestablished prerequisites:

Possess a current instrumenrating (other than tactical). Have held the rating for thprevious two years and flown minimum of 1b hours of actuainstruments as an IP, pilot or copilot during the past two years incategory; or had the rating onyear provided he flew 10 hours oI as an IP or pilot.


27/68

Minimum of 1,000 hours with500 in category. Have a certificate of proficiency signed by an instrument flightexaminer who has been delegatedthe authority to determine qualifications of aviators for award orretention of instrument r a ~ i n g sTests are now being conductedto determine prerequisites for theexaminer programs commensuratewith the abilities of aviators available and acceptable in terms ofcourse length.A third problem area also related to the shortage of qualifiedaviators (particularly junior officers and warrants) is that the examiner field apparently has lostsome of its former appeal. Manyof those aviators, particularly warrant officers, who meet or comeclose to meeting the prerequisitesare reluctant or even unwilling toattend the course. There is noquestion that the working examiner puts in long hours above andbeyond his regular duties conducting checkrides for personnel whocan't get away during the week. tis also true that he gets called uponto fly the key mission the nightmedevac or the AI mission thatmust go, even though there maybe other qualified pilots available.

t is also no secret that the examiner doesn't get paid any more orpromoted any faster because he isan examiner. In fact, i f he is conscientious and does his job the wayhe has been trained, he may evenoccasionally step on the wrongfoot. He's the safety officer, thestandardization officer and the OldMan's pilot more often than not,in addition to his regular duties.And finally, some will tell you alsothat the examiner has lost prestigebecause the course prerequisiteshave, of necessity, been reduced.

Now, having addressed theseproblem areas, it is important todiscuss a few facts and to see whatis being done to resolve theseproblems.JULY 1969

Fact Number One No matterwhat innovations, new techniquesand adjusted prerequisites may beincorporated into the examinerprograms the end result, the manwho qualifies as an examiner, isstill at the top of his field. Therewill be and has been no loweringof standards. He may not look oldenough to shave or to buy a drinkin some states but when he sayshe's an examiner, he's as professional and knowledgeable as anyexaminer the system has ever produced in some ways better for heknows all the latest proceduresand techniques.Fact Number Two A test classat USAAVNS qualified four examiners in the summer of 1968,

two fixed wing and two rotarywing, from aviators with minimuminstrument experience. The knowledge gained from these tests provided considerable input into twoDA directed test courses conductedfrom January to April 1969. Theselatter test courses had the following as test objectives:

To establish the most realisticcourse prerequisites in view of theoverall situation throughout Armyaviation versus course length. To evaluate the use of programmed instruction and syntheticflight training in the examinercourse. To evaluate the feasibility ofoverlapping courses to permit students in the examiner phase toconduct checkrides and ' trainingfor incoming students. This wouldprovide a savings in aircraft aswell as permit more classes peryear. To evaluate extensive application of jumpseat training for thestudent not actually at the controls.In addition, two other tests wereinitiated in February 1969 atUSAA VNS to determine the requirements for qualifying substantial numbers of experienced instructors at USAAVNS as exam-

iners with the mmnnum of additional resources and minimum impact on the training departments.In one test selected IPs were required to establish the necessaryproficiency (primarily as a guineapig for the examiner courses)during breaks in the training schedule when they were not requiredto fly their students. In the othertest, the IPs selected establishednot only the necessary proficiencybut also completed examiner academics during periods when theywere not needed to fly students.Upon completion of these requirements, an aircraft and an examinerwere allocated for the necessaryexaminer training.

Fact N umber Three Anotherarea receiving considerable attention with regard to the problem ofthe shortage of examiners involvesthe establishment of procedures toidentify the potential examiner during his earlier training. His recordswill be annotated during flightschool, subsequent flight trainingand MOl to indicate that he hasthe necessary ability and integrityto become an examiner. This ideaof identifying students during earlytraining has application, of course,not only in the examiner program,but throughout the Army aviationfield.One final step to improve theexaminer program can be made byall commanders worldwide thatis to make the entire businessmore attractive. This involvesmany intangibles. It could include,however, becoming aware of theextra efforts of the examiner andmaking adjustments accordingly.Needed will be increased command

emphasis on instrument programsin field units (which would thenprovide more aviators in the system with the necessary prerequisites), and finally recognizing thatthis man, regardless of his rank,age or experience in terms of hoursand years, has achieved the pinnacle of our profession.25


28/68

ieutenant olonel Theo C Watkins

26 U s ARMY AVIATION DIGEST


29/68

D OZENS of operational research studies have been concluded; countless conferences within and out of military and privateindustry circles have addressed thesubject and millions of dollars ofresearch and development monieshave been spent on developing newaircraft engine fuels. The mostpromising fall-out of these effortsis the use of Methane CHI) as afuel for aircraft engines.The purpose of this article is toacquaint the reader with the Army'sapproach to Methane, as visualizedby the U. S Army Combat Developments Command (USACDC).USACDC is charged by Department of the Army with determininganswers to the following, for 20years into the future. How should the Army fight? How should the Army beequipped? How should the Army be organized?The mission of USACDC isepitomized by our motto, Visionto Victory, and those of us directly involved with the CDC mission, are proud of its contributionsto the overall Army mission. Somuch for the commercial; Methane

is a major component of naturalgas. t also is a cryogenic substance, which means it is very cold( - 260 degree F) in a liquid state.Engine and Fuel Background-The past 15 years have seen arevolution in aircraft engines withthe change over from reciprocatingto gas turbine power. The Armyhas provided the main impetus inthis accomplishment. The currentgeneration of gas turbine engines

using the JP fuel series has provided a significant weight to horsepower reduction with. quantumjumps in reliability and maintainability. Further significant progressin the field requires a solution permitting higher turbine inlet temperatures, and a reduction in specific fuel consumption SFC).JULY 1969

Current state-of-the-art technologyindicates an upper limit has beenreached in both these areas usingthe JP fuel series.dvantages of Methane s aFuel At this point let me invitethe reader who may be assumingthat a highly technical presentationwill follow, to please continue withme since what follows is outlinedin soldiers terms and a concertedeffort has been made to stay awayfrom engineering language. Beforeenumerating the advantages ofMethane I should explain how itcan function as an aircraft enginefuel. There are three key points: Methane is a cryogenic fuelstored at - 260 degrees F andpumped as a liquid.t can be heated and vaporizedwhile concurrently cooling enginecomponents. It is injected into an enginecombustion chamber as a gas.H eat Efficiency The efficiencyof a fuel is frequently judged bythe amount of heat released perpound. This is true for fuels usedto heat your house or propel yourcar. Methane releases approximately 18 percent more heat perpound than the JP series.Higher Turbine Engine Inlet

Temperatures As outlined earlier,Methane is a cryogenic substance.As such it can absorb heat in theneighborhood of 1,250 degrees F(525 degrees F for JP) withoutbreaking down. This feature canbe used to cool turbine blades andother components, and permit increases in inlet temperatures toapproximately 4,000 degrees F(curret inlet temperatures usingJP fuel peak at approximately2,200 degrees F). The fall-out ofthese advantages is decreased specific fuel consumption SFC) andgreater engine performance. Figure1 outlines this advantage in chartform. .

Noise Reduction Noise reduction on the battlefield is receivinga great deal of attention in the

Army. Methane fuel requires 50percent less air for combustionthan JP. This feature producestwo advantages: a reduction in engine size for a particular horsepower requirement and a significant reduction in noise due to lessair entering and leaving the engine.Reduction of Infrared SignatureThe widespread acceptance ofthe airmobility concept with theintended movement of air vehiclesall over the battlefield has causedmany of us to meditate on the consequences of the enemy launchinga heat seeking device up our tailpipes. t is possible to use the cooling properties of Methane in theengine exhaust sections and reduceinfrared signatures to an accept

able risk category (see figure 2).Smog Reduction Many levelsof the military, the government andindustry are agonizing over theproblems of smoke control fromair vehicles using JP fuels. Theproblem is so acute it may eventually preclude aircraft operation incertain high smog regions. Methaneby comparison, is a clean burningfuel. Carbon monoxide is drastically reduced because Methanecontains less carbon in proportionto hydrogen. Soot and sulfur in theexhaust stream are negligible.

Safety Those of us who driveair vehicles are acutely aware ofthe hazards of post-crash and refueling fires. Studies conducted byUSABAAR indicate the fatalityrate is very high in accidents wherefire has broken out. Methane as afuel has four safety considerations: Methane in vapor form) isdifficult to ignite (1,200 degrees F

vs 500 degrees F for JP). Rupture of fuel tanks duringan accident would permit Methaneto vaporize and float into he airaway from the crash site. The cryogenic properties ofMethane would assist in preventing or quenching fires due to its

27


30/68

1800 -2200 0 F)J P FUEL (CURRENT TIT)JP FUEL 2400 0 F)CH4 FUEL 2400 F) (METHANE)CH 4 FUEL 3000 F) (METHANE)

super-cooling effect and high ignition point. Methane is non-toxic to fuelhandling personnel.Cost and National Considera-tions Methane is plentiful andcheap. Figure 3 outlines the estimated reserves of natural gas andpetroleum. It takes little reflectionto deduce the fact that nationalobjectives and foreign alliancescould be influenced by these fuel

ESTIMATED ENGINE PERFORMANCESPECIFICHORSEPOWER,HP/LB/SEC

FIGURE 1

90-100200220305

reserves in the future. It should beemphasized that only 10 to 20 percent of the total petroleum reservesare suitable for use as aviation fuel.Maintenance and Supply Thefinal advantage of Methane is itspotential influence in the logisticalfield. Aircraft have always beenexpensive to buy and operate. Thisfact is particularly applicable torotary wing aircraft, where the totalcost of one flying hour for a large

BRAKE SPECIFICFUEL CONSUMPTION

AT MAX POWER0.64-0.690.460.400.39

helicopter exceeds 300 . Much othis cost is due to spare parts anmaintenance requirements, witengines constituting a major potion of the requirements for sparparts. Methane, in contrast to Jfuel, is a clean burning fuel anproduces very little coke and gumto block passages and create engine problems.

In the supply field, the lonlogistical tale associated with shipCOURTESY OF FLORIDA

R D CENTER OFPRATT WHITNEY AIRCRAFT

DIRECT RADIATION FROM CONCENTRATIONSOF H20 AND CO2 IN EXHAUST GASESDIRECT RADIATION FROM VISIBLE HOT WALLS

REFLECTED RADIATION FROM NONVISIBLE HOT PARTSTYPICAL TURBOJET ENGINE SOURCES OF INFRARED RADIATION

FIGURE 2.

28 U. S RMY VI TION DIGES


31/68

NORTH AMERICAWORLD

ESTIMATED RESERVESBILLIONS OF STD CU FT)

NATURAL GAS1,750,00015,300,000

PETROLEUM1,580,00011,700,000

1 BARREL PETROLEUM: 5850 FT3 NATURAL GAS (EQUAL ENERGY)REF U S GEOLOGICAL SURVEY 1964.

ping and storing POL products iswell known. Analysis of state-ofthe-art technology by CDC indicates liquefaction plants capable ofbeing transported are presentlyavailable. During future conflicts,these plants could be set up inareas of the world w

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Army Aviation Digest - Jul 1969

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