NORTH AMERICAN FJ-5 FIGHTERA Navalized Derivative of the F-107A

Jared A. Zichek

A MERICAN A EROSPACE A RCHIVE 2

The American Aerospace Archive is published periodically by Jared A. Zichek (6021 La Jolla Hermosa Ave, La Jolla, California 92037) and is printed and distributed by MagCloud (www.jaredzichek.magcloud.com). American Aerospace Archive Number 2.01 (ISSN 1943-9636) is copyright 2008 by Jared A. Zichek. All rights reserved. All featured text and images are copyright 2008 their respective copyright holders. Reproduction of any material in part or in whole without its creator's permission is strictly forbidden. The Ameri-can Aerospace Archive accepts no responsibility for unsolicited manuscripts, photos, art or other materials. Submissions are considered on an invitational basis only. Email your comments and suggestions to editor@aeroarchivepress.com and visit our website at www.aeroarchivepress.com.

ABOVE: Insert caption here.

COVER: Photo of the North American FJ-5 wind tunnel model.

he July 6, 1955 proposal for the North American Aviation (NAA) "Improved FJ-4," also designated

the FJ-5 (by the company, not by the Navy), was essentially a navalized ver-sion of the Air Force F-107A. The latter originated from an in-house study for a successor to the F-100A Super Sabre, dating from March 4, 1952. Designat-ed by the company as the F-100B, this aircraft would evolve into the F-100BI interceptor, which featured a variable-area air intake under a sharply pointed nose radome. Further refinement of the design led to the inlet being moved directly above and immediately behind the cockpit. As an interceptor, the pro-posal failed to impress the Air Force, and the aircraft was subsequently rede-signed into a fighter-bomber, receiving the F-107A designation on July 8, 1954. Ordered as a back-up to the Republic F-105 Thunderchief, the F-107A's ca-reer was cut short by the unreliability of its variable-geometry inlet and lack of funding. Only three aircraft were built, ending their days in aerodynamic test-ing at NACA.1

The FJ-5 appears to have been an attempt by NAA to leverage the work it had done on the original interceptor variant of the F-107A, repurposing it to meet Navy requirements. It was pitched to the Navy as an evolution of the FJ-4 Fury, a capable but unspectacular fight-er that was largely relegated to Marine Corps units. In fact, the production FJ-5 would have been virtually a new design that shared little in common with its predecessor. Only the prototype shared the wing and main landing gear of the FJ-4, as will be discussed in the follow-ing sections.

Design Information

The proposed airplane design com-bined the FJ Series airplane with a Gen-eral Electric J79 afterburning engine, to provide a carrier-suitable, supersonic, extremely high altitude, air superiority day fighter with interceptor capabilities.2 Performance estimates for the produc-

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Above: General arrangement drawing of the basic North American FJ-5 fighter.Cover: Photo of the FJ-5 one-tenth scale wind tunnel model.

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tion airplane were based on J79-GE-2 engine performance circa March 15, 1953. However, GE test data for the J79-GE-2, with increased airflow rates, indi-cated that the 1957-58 production engine would have improved performance. The production airplane, as revised, reflected increased performance as per the table below right.

The Model FJ-4 airplane wing was redesigned to a new "thinness" ratio of five percent with an increase in area to 400 sq ft. A new "four percent" empen-nage and a high fineness ratio, low drag fuselage were also incorporated. Other design features included provisions for carrying 2 or 4 folded fin "Sidewinder" missiles; 2 internal rocket packages ac-commodating 68 unguided "Gimlet" rockets; or four 30 mm MK 4 cannons with 104 rounds of ammunition per gun; installation of search and range radar (NASSAR) with provisions for the al-ternate installation of a government fur-nished Magnavox radar; and an internal fuel capacity of 1,040 gallons. Strength was provided for a load factor of 6.0 g's at a design gross weight of 18,844 lbs.

The proposal also included prelimi-nary drawings depicting alternate con-figurations of the airplane designed for: 1) supersonic photo reconnaissance mis-sions and 2) super performance fighter and interceptor missions with rocket en-

gine augmentation. As showing in the drawings on pages 32-35, the proposed production design was readily adaptable to these alternate configurations with a minimum of changes.

To initiate the program and also provide production lead time, North American proposed to fabricate an en-gine test stand, one engine prototype, one production prototype airplane and

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Engine J79-GE-2 (March 15, 1953) J79-GE-2 (1957-58 Modified)

Max Speed, 10,000 ft(Kts/Mach)

663/1.04 698/1.095

Max Speed, 35,000 ftMax Power (Kts/Mach)

828/1.44 909/1.58

Combat CeilingMax Power (ft)

58,500 60,000

Rate of Climb, 10,000 ft(ft per minute)

27,900 32,500

Combat Radius(5 mins A/B and 15 mins military power at combat weight and 40,000 ft ceiling)

450/2.1

Extended Combat Radius (20 mins military power at combat weight and 40,000 ft ceiling)

584/2.62

Turning Performance Hold-ing 50,000 Altitude (g)

1.6 1.67

Max Thrust 14,350 15,750Mil Thrust 9,292 10,200Normal Thrust 8,890 9,760

a static test airplane. The engine pro-totype airplane would have been fabri-cated from a fuselage and empennage designed for the production version of the new airplane, and a Model FJ-4 wing and main landing gear.

Simplified inboard profile of the basic North American FJ-5; more detailed inboard profiles of the prototype and basic version can be found on pages 6-7 and 10-11, respectively.

Detail Specification

North American submitted an 83 page Detail Specification document with their FJ-5 proposal; too large and tech-nical to reproduce here, the key sections are summarized in the following para-graphs.3

Introduction

Operation The FJ-5 was designed for operation from land fields and from CVA-34, CVA-19, and CVA-59 and su-perior class carriers equipped with the C11 catapult, the Mk 7 arresting gear, and barricade equipment. At the ba-sic catapulting design gross weight, the airplane was capable of takeoff from the deck of a carrier also equipped with C7 or F8 catapults. The airplane was opera-ble within the 220 ft runout rating of the

Mk 7 arresting gear and was also oper-able with the Mk 5 (155 ft runout rating) arresting gear with increased wind-over-deck required.

Interior Arrangement The inte-rior arrangement consisted of the fol-lowing:

a) A pressurized enclosed cockpit for the pilot. The cockpit was provi-sioned with the controls and instruments required for operation of the airplane.

b) A radar compartment located in the nose of the fuselage to house the NASARR equipment. Space provisions were made for the alternate installation of Magnavox radar equipment.

c) Two armament bays were locat-ed in the underside of the fuselage, aft of the cockpit and forward of the wing, for carrying Sidewinder missiles. Space provisions were made for the alternate installation of 2-4 folded fin Sidewind-

ers, or two Gimlet rocket packages, or 4 MK 4 30 mm guns.

d) An equipment bay located in the forward fuselage, between the armament bays, to house the hydraulic equipment.

e) An equipment bay located aft of the cockpit to house the electronic, heat-ing and ventilation equipment.

General

Cockpit Interior The interior of the cockpit, including bulkheads, floors, instrument panels, etc., would have been finished in dark gray Color No. 3615, ex-cept areas as follows which would have been non-specular black, Color No. 3725:

1) Canopy and windshield framing (above rails) which tended to cause sun or light glare conditions in the cock-

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Three-view drawing of the North American FJ-5 engine prototype, which featured the wing and main gear of the FJ-4 Fury. Externally, the type bore a strong resemblance to the Air Force F-107A, though there were some important differences. With an empty weight of 14,998 lbs, the FJ-5 was 7,698 lbs lighter than an empty F-107A. The inlet was less steeply raked and of an oval cross section, unlike the sharply swept, square section intake of its Air Force counterpart. The FJ-5's wide track main gear attached to the wing and folded inwards towards the fuselage, while the F-107A's narrow track main gear attached and folded directly into the fuselage. Other obvious differences include the wing folding, arresting hook, and the higher nose-up attitude of the FJ-5, all of which optimized the type for carrier operations.

All images are scanned from documents held by the National Archives at College Park, Maryland, RG 72.

pit (other framing would have been gray).

2) Horizontal surfaces above the top of the instrument panel and other horizontal surfaces above the canopy rails, which could have been sun-glare or light glare areas to the pilot.

3) All plastic lighting plates.4) Instrument knobs.5) "Post Light" type instrument

lighting fixtures.6) Rims of instrument cover

glasses.7) Instrument placards.8) Areas containing lettered

information. These were to have been boxed in a black-painted background. The border of the box extended at least 1/4" beyond the letters.

9) Control knobs and handles

remained painted as individ-ually specified.

Exterior Surfaces (Except Lead-ing Edges) Exterior aluminum sur-faces would have been anodized, treated, and painted as follows: One coat Spec. MIL-C-8514 pretreatment coating plus one coat of Spec. MIL-P-6889 or MIL-P-8585 zinc chromate primer plus two coats of No. 1755 White gloss lacquer on surfaces viewed from below, and two coats of No. 3635 gray camouflage lac-quer on vertical surfaces and surfaces viewed from above.

Leading Edges Clad or 61S alumi-num leading edges of wings, horizontal and vertical stabilizers and fuselage nose would have been unpainted and anod-ized. Unclad aluminum leading edges would have been anodized or received MIL-C-5541 treatment; regardless of the surface treatment used, these surfaces

would have been coated with a rain ero-sion resistant finish consisting of MIL-C-8514 pretreatment coating plus MIL-P-8585(Aer) zinc chromate primer plus .005" of Minnesota Mining Company aluminized Corogard EC-843 Special or equivalent. The leading edges of plastic parts would have been coated with a rain erosion resistant coating consisting of MIL-C-8618(Aer), Finish II material.

Insignia and Markings Insignia would have been affixed with a complete finish scheme and the SR-2h markings applied in a contrasting black color.

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Wing Group

The wing group consisted essential-ly of two removable inboard wing panels containing trailing edge flaps and slot-deflector ailerons, two removable fold-ing outer panels and two removable wing tips. The wing panels were attached at the fuselage center line. The wing lead-ing edge was movable for use as a high lift device. A barricade strap retaining device was provided on the leading edge of each wing panel. An electrically actu-ated trimmer was provided on the trail-ing edge of the right wing, outboard of the flap, for lateral trimming of the air-plane.

Wing Folding It would have been possible to fold or spread the wings in 20 seconds or less in winds up to 60 kts from +/- 45º ahead. The outer wing pan-els folded by means of hydraulic power controlled from the cockpit. Provision was also made for wing folding from an external source of power. Access to the wing fold area was provided to permit manual unlocking of the wing fold lock

pins by means of a drive tool.Slot-Deflector Ailerons Twelve

mechanically controlled hydraulically powered control surfaces, three each located on the upper and lower surface of each inboard wing panel between the main rear spar and the flap hinge line, were provided for lateral control of the airplane.

High Lift and Drag Increasing De-vices Wing trailing edge flaps, droop-able wing leading edges, and a supercir-culation system were provided. All high lift devices operated in conjunction with the wing flaps, except that a separate control was provided for the supercircu-lation system.

Tail Group

The tail group consisted of a con-trollable horizontal stabilizer, a control-lable rudder and a fixed vertical fin.

Stabilizer The stabilizer pivoted on an axis perpendicular to the airplane center line and controlled the longitudi-nal flight of the airplane.

Fuselage

The fuselage was of semi-mono-coque metal construction and consisted of two main sections. The forward sec-tion contained the engine air inlet duct, pressurized cockpit, fuel tanks, the main and nose wheels, the speed brake and the forward section of the engine. The fuselage aft section housed the aft sec-tion of the engine, the entire afterburner, and the arresting hook. The two fuselage sections were attached through the use of quick-disconnect tension-type fittings which afforded easy access for engine re-moval.

Cabin Enclosure The cockpit was enclosed and pressurized. Canopy seals were pressurized when the canopy was latched and the engine was operating. The movable section of the canopy was capable of being electrically-operated for normal ingress and egress. Provision was made to prevent inadvertent open-ing of the canopy when the engine was operating. The canopy was jettisonable throughout the speed range of the air-

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Detailed inboard profile of the North American FJ-5 engine prototype. Note-worthy features included the retractable fueling probe, extendable ram air turbine (shown immediately below), and the pi-lot's full pressure suit and helmet. The peculiar inlet location dictated the odd method of opening the canopy, which slid upwards on rails like the F-107A.

plane for emergency egress of the pilot. The canopy had provisions for positive emergency jettisoning should the main power fail. The movable section was of plastic. Provision was made to maintain the watertightness of the canopy while the airplane was parked during heavy storms by using an external air pressure source to pressurize the canopy seal.

Windshield The center panel was made of bullet resistant glass, while lam-inated plate glass was used in the wind-shield side panels. A hot air removal sys-tem was provided for the left and center windshield panels.

Speed Retarding Devices A re-tractable speed brake was provided on the underside of the fuselage. Provision was made for emergency dumping of speed brake hydraulic pressure.

Alighting Gear

The alighting gear consisted of two main landing gear assemblies and a nose wheel assembly.

Tires The main wheel tires were

26" x 6.6", Type VII, EHP, 14-ply rating (tubeless) and the nose wheel tire was 20" x 5.5", Type VII, EHP, 12-ply rating (tubeless).

Gear Retraction The alighting gear was hydraulically operated and electrically sequenced. Indicators were provided to indicate the position of the wheels. In addition, a light was incor-porated in the landing gear control han-dle to indicate when any wheel was not locked in the same position as indicated by the handle. The alighting gear was ca-pable of being extended or retracted in not more than 10 seconds at air speeds up to 200 kts. Provision was made for emergency lowering of the retractable alighting gear in case of power failure. Where practicable, gravitational emer-gency extension would have been em-ployed.

Tail Skid The underside of the aft-most portion of the rear fuselage was suitably reinforced to prevent structural damage during arrested landings.

Surface Control System

Complete surface controls were provided for the pilot. The cockpit con-trols were of the conventional stick and rudder pedal design. Two half hinge moment surface control power systems were provided and operated simultane-ously to furnish full power for actuation of the slot-deflector ailerons and stabi-lizers. These were operated by irrevers-ible hydraulic actuator assemblies. Each assembly consisted of two separate and independent valve and cylinder combi-nations, with the cylinders mounted in tandem and driving a common piston rod. An electro-hydraulic valve was mounted on the stabilizer actuator as-sembly to provide normal electrical con-trol of the stabilizer actuator from the pilot's flight controls. An alternate con-trol consisting of a mechanical linkage of cables, push-rods, and levers were au-tomatically engaged to the stabilizer ac-tuator should the actuator fail to follow the control stick within pre-determined tolerances. A mechanical control system

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