General Electric ran performance tests of its 32,000 lb.-thrust F 110-GE-132 engine for Block 60 F-16s at its Peebles, Ohio, facility.The engine, the first complete, purpose-built F 110-132 began about 30 hr. of runs at Peebles on an outdoor test stand. Preceding those trials were 30 hr. of tests conducted in indoor facilities at GE’s Evendale, Ohio, plant. Those assessments were finished in midNovember 2000.
Thrust is the biggest difference between the F 110-132 and the production version of the F 110, the F 110-129. The newer engine is capable of generating about 3,000 lb more thrust under sea-level static conditions. To generate that power, the -132 is fitted with a 5% more efficient fan that features integrally bladed disk construction. The new powerplant also has a filament wound graphite-epoxy fan duct designed to handle the loads associated with thrust vectoring, should that technology ever be added to the engine. The F 110-132 is equipped with a radial augmentor, similar to the unit found in the F/A-18E/Fs F414 engine. It improves operability at higher thrust levels and helps eliminate augmentor screech-high-frequency, standing sound waves that can damage engine components. Also offered as an option on the F l10-132 is an ejector nozzle that directs a thin film of cool air from the engine bay around the nozzle’s flaps and seals. Cooling is great enough to reduce the temperatures of those components by 400-800 deg. F, depending on operating conditions. Taken together, the F 110-132 improvements can be used to generate additional thrust, or to increase engine life if thrust is limited to 29,000 lb. This means inspections now carried out on F 110s at 4,300 cycles would be delayed to 6,000 cycles. F 110-132s operated under the increased durability option would carry the official USAF designation of F 110-GE-132As. Despite the designation, the service has not taken any steps toward procurement.
Applications: F-14B/D Super Tomcat F-15S/F-15K/F-15SG/F-15SA Strike Eagle F-16 Fighting Falcon General Dynamics F-16XL Mitsubishi F-2
Specifications:
F110 Type: Afterburning turbofan Length: 182.3 – 232.3 in (463 – 590 cm) Diameter: 46.5 in (118 cm) Dry weight: 3,920 – 4,400 lb (1,778 – 1,996 kg) Compressor: 2 spool: 3 fan and 9 high pressure compressor stages Combustors: annular Turbine: 2 low-pressure and 1 high-pressure stages Maximum thrust: 27,000 – 28,000 lbf (120 – 125 kN) Overall pressure ratio: 29.9:1 – 30.4:1 Turbine inlet temperature: 2750F (1510C) Thrust-to-weight ratio: 6.36:1
After the successful development in the late 1960s of the TF39 for the C-5 Galaxy, GE offered a more powerful development for civilian use as the CF6, and quickly found interest in two designs being offered for a recent Eastern Airlines contract, the Lockheed L-1011 and McDonnell Douglas DC-10.
Although the L-1011 would eventually select the Rolls-Royce RB211, the DC-10 stuck with the CF6, and entered service in 1971. It was also selected for versions of the Boeing 747. Since then, the CF6 has powered versions of the Airbus A300, 310 and 330, Boeing 767, and McDonnell Douglas MD-11.
The NTSB issued warnings regarding the cracking of the high pressure compressor in 2000 and failure of the low pressure turbine rotor disks in 2010.
The basic engine core formed the basis for the LM2500, LM5000, and LM6000 marine and power generation turboshaft. GE intends to replace the CF6 family with the GEnx.
Variants:
CF6-6 This initial version of the CF6 comprises a single stage fan, with one core booster stage, driven by a 5-stage LP (low pressure) turbine, supercharging a 16-stage HP (high pressure) axial compressor driven by a 2-stage HP turbine; the combustor is annular; separate exhaust nozzles are used for the fan and core airflows. The 86.4 in (2.19 m) diameter fan generates an airflow of 1300 lb/s (590 kg/s), resulting in a relatively high bypass ratio of 5.72. The overall pressure ratio of the compression system is 24.3. At maximum take-off power, the engine develops a static thrust of 41,500 lb (185.05 kN).
A complete disintegration of a CF6-6 fan assembly resulted in the loss of cabin pressurization of National Airlines Flight 27 over New Mexico, USA in 1973. The failure of a CF6-6 was the primary cause of the Sioux City, Iowa USA crash of United Airlines Flight 232 in 1989. CF6-50 The CF6-50 series are high-bypass turbofan engines rated between 51,000 and 54,000 lb (227.41 to 240.79 kN) of thrust. The CF6-50 was developed into the LM5000 industrial turboshaft engines. It was launched in 1969 to power the long range McDonnell Douglas DC-10-30, and was derived from the earlier CF6-6.
Because a significant increase in thrust and therefore core power was required not long after the -6 had entered service, General Electric could not increase (HP) turbine rotor inlet temperature significantly, so they took the very expensive decision to reconfigure the CF6 core to increase its basic size. They achieved this by removing two stages from the rear of the HP compressor (even leaving an empty air passage, where the blades and vanes had once been located). Two extra booster stages were added to the LP (low pressure) compressor, which increased the overall pressure ratio to 29.3. Although the 86.4 in (2.19 m) diameter fan was retained, the airflow was raised to 1450 lb/s (660 kg/s), yielding a static thrust of 51,000 lbf (227 kN). The increase in core size and overall pressure ratio significantly raised the core flow, resulting in a decrease in bypass ratio to 4.26.
In late 1969, the CF6-50 was selected to power the then new Airbus A300. Air France became the launch customer for the A300 by ordering six aircraft in 1971. In 1975, KLM was the first airline to order the Boeing 747 powered by the CF6-50. This led further developments to the CF6 family such as the CF6-80. The CF6-50 also powered the Boeing YC-14 USAF AMST transport prototype. The basic CF6-50 engine was also offered with a 10% thrust derate for the 747SR, a short-range high-cycle version used by All Nippon Airways for domestic Japanese operations. This engine is termed the CF6-45.
Four uncontained failures of CF6-45/50 engines in the preceding two years prompted the U.S. National Transportation Safety Board to issue an “urgent” recommendation to increase inspections of the engines on U.S. aircraft in May 2010. None of the four incidents of rotor disk imbalance and subsequent failure resulted in an accident, but parts of the engine did penetrate the engine housing in each case.
CF6-80 The CF6-80 series are high-bypass turbofan engines with a thrust range of 48,000 to 75,000 lb (214 to 334 kN). Although the HP compressor still has 14 stages, GE did take the opportunity to tidy-up the design, by removing the empty air passage at compressor exit.
Following a series of high-pressure turbine failures, some which resulted in 767s being written off, the FAA has issued an airworthiness directive mandating inspections for over 600 engines. The NTSB believed that this number should be increased to include all -80 series engines with more than 3000 cycles since new or since last inspection. The -80 series is divided into three distinct models.
CF6-80A The CF6-80A, which has a thrust rating of 48,000 to 50,000 lb (214 to 222 kN), powered two twinjets, the Boeing 767 and Airbus A310. The GE-powered 767 entered airline service in 1982, and the GE powered A310 in early 1983. It is rated for ETOPS operations.
For the CF6-80A/A1, the fan diameter remains at 86.4 in (2.19 m), with an airflow of 1435 lb/s (651 kg/s). Overall pressure ratio is 28.0, with a bypass ratio of 4.66. Static thrust is 48,000 lbf (214 kN). The basic mechanical configuration is the same as the -50 series.
CF6-80C2 For the CF6-80C2-A1, the fan diameter is increased to 93 in (2.36 m), with an airflow of 1750 lb/s (790 kg/s). Overall pressure ratio is 30.4, with a bypass ratio of 5.15. Static thrust is 59,000 lb (263 kN). An extra stage is added to the HP compressor, and a 5th to the LP turbine.
The CF6-80C2 was certified on eleven widebody aircraft models including the Boeing 747-400, and McDonnell Douglas MD-11. The CF6-80C2 is also certified for ETOPS-180 for the Airbus A300, Airbus A310, Boeing 767, and, as the F138-GE-100, the U.S. Air Force’s C-5M Super Galaxy.
CF6-80E1 The CF6-80E1 is a derivative of the CF6 family applied to the Airbus A330, with thrust rating of 67,500 to 72,000 lb (300 to 320 kN).
Other variants: The industrial and marine development of the CF6-80C2, the LM6000 Series, has found wide use including fast ferry and high speed cargo ship applications, as well as in power generation.
Applications:
CF6-6 McDonnell Douglas DC-10-10
CF6-45 Boeing 747-100SR
CF6-50 McDonnell Douglas DC-10 McDonnell Douglas DC-10-30 KC-10 Extender Boeing 747 Boeing 747-200 Boeing 747-300 Boeing E-4B Airbus A300 Boeing YC-14
CF6-80A Boeing 767 Airbus A310
CF6-80C2 Boeing 767 E-10 MC2A Boeing E-767 Boeing KC-767 Boeing 747 Boeing 747-400/-400ER Boeing VC-25 (Air Force One) Lockheed C-5M Galaxy McDonnell Douglas MD-11 Airbus A300-600 Kawasaki C-2
CF6-80E1/E2 Airbus A330
Specifications:
CF6-50 Type: Turbofan Length: 183 in (4.65 m) Diameter: 105 in (2.67 m) Dry weight: 8,966 – 9,047 lb (4067 kg – 4104 kg) Compressor: 1 stage fan, 3 stage low pressure, 14 stage high pressure axial compressor Combustors: annular Turbine: 2 stage high pressure, 4 stage low pressure turbine Maximum thrust: 52,500 – 61,500 lbs (234.1 – 274.23 kN) Overall pressure ratio: 29.2:1 – 31.1:1 Bypass ratio: 4.24 – 4.4 Thrust-to-weight ratio: 5.6:1 – 6:1
The F101 was developed specifically for the Advanced Manned Strategic Aircraft, which became the B-1A. The F101 powered the four development aircraft from 1970 to 1981. The B-1A was officially cancelled in 1977. However the flight test program continued. General Electric was awarded a contract to further develop the F101-102 engine variant. This turbofan eventually powered the B-1B from 1984, entering service in 1986. The B-1’s four F101 engines helped the aircraft win 61 world records for speed, payload and range.
The GE F110 fighter engine is a derivative of the F101, designed using data from the F101-powered variant of the F-16 Fighting Falcon tested in the early 1980s. The F101 also became the basis for the highly successful CFM56 series of civil turbofans.
The General Electric F101 is an afterburning turbofan jet engine, in full afterburner it produces a thrust of 30,000 pounds-force (130 kN). The F101 was GE’s first turbofan with an afterburner.
Specifications:
F101-GE-102 Type: Turbofan Length: 181 in. (460 cm) Diameter: 55 in. (140 cm) Dry weight: 4,400 lbf (1995 kg) Compressor: Axial, 2 stage fan, 9 stage high pressure compressor Combustors: Annular Turbine: 1 stage high pressure turbine, 2 stage low pressure turbine Maximum power output: 31,000 lb (138 kN) (with afterburner) Overall pressure ratio: 26.8:1 Specific fuel consumption: 2.46 lb/lbf-hr (max thrust) Thrust-to-weight ratio: 7.04:1 (afterburner)
The first American turboprop engine was the General Electric XT31, first used in the experimental Consolidated Vultee XP-81. The XP-81 first flew in December 1945, the first aircraft to use a combination of turboprop and turbojet power.
The T31 engine was the first American turboprop engine to power an aircraft. First run in May 1945, it made its initial flight in the Consolidated Vultee XP-81 on 21 December 1945. The T31 was mounted in the nose; a J33 turbojet engine mounted in the rear fuselage provided added thrust. The T31 was also used on the Navy XF2R-1, similarly powered by a turboprop/turbojet engine combination.
The engine was to have been flown experimentally on a Curtiss XC-113 (a converted C-46), but the experiment was abandoned after the XC-113 was involved in a ground accident. Only 28 T31s were built; none were used in production aircraft, but improved production turboprop engines were developed from the technology pioneered by the T31.
A derivative of the T31, the General Electric TG-110, given the military designation T41, was ordered but subsequently cancelled.
Applications: Consolidated Vultee XP-81 Curtiss-Wright XC-113 XF2R Dark Shark
Specifications:
XT31 Type: Turboprop Dry weight: 1,980 lb Maximum power output: 2,300 shp (design) at 13,000 rpm. (1,145 propeller rpm)
The General Electric GE36 was an experimental aircraft engine, a hybrid between a turbofan and a turboprop, known as an Unducted Fan (UDF) or propfan. The GE36 was developed by General Electric Aircraft Engines and first run in 1986.
A General Electric F404 military turbofan was used as the basis of the GE36. The F404 mixed exhaust stream discharged through a seven-stage low pressure (LP) turbine, where each stator ring was ‘unearthed’ and free to move in the opposite direction to that of the rotors. One set of open rotor, variable pitch, fan blades was connected to the LP turbine rotor system, while the other set was connected to the contra-rotating LP turbine stators. The scimitar shape of the fan rotor blades enabled high flight speeds (about Mach 0.75) to be obtained. GE used a low speed, (effectively) 14 stage, LP turbine, rather than a conventional high speed LP turbine and reduction gearbox, to drive the fan rotor blades.
Although the engine demonstrated an extremely low specific fuel consumption, cabin noise levels were a problem, even though the engines were mounted at the rear of the test aircraft.
The General Electric/Allison J35 was originally developed by General Electric (GE company designation TG-180) in parallel with the Whittle-based centrifugal-flow J33, and was the United States Air Force’s first axial-flow (straight-through airflow) compressor engine. The J35 was fairly simple, consisting of an eleven-stage axial-flow compressor and a single-stage turbine. With the afterburner, which most models carried, it produced 7,400 lbf.
Like the J33, the design of the J35 originated at General Electric, but major production was by Allison.
The J35 first flew in the XP-84 in 1946. Late in 1947, complete responsibility for the production of the engine was transferred to the Allison Division of the General Motors Corporation. Some J35s were built by GM’s Chevrolet division. More than 14,000 J35s had been built by the time production ended in 1955.
The J35 was used to power the Bell X-5 variable-sweep research aircraft and various prototypes such as the XB-43 Jetmaster, XB-45 Tornado, Convair XB-46, XB-47 Stratojet, Martin XB-48, and Northrop YB-49. It is probably best known, however, as the engine used in two of the USAF’s leading fighters of the 1950s, the F-84 Thunderjet and the F-89 Scorpion.
A larger development of the engine was later produced as the Allison J71, producing around 10,000 lbf.
The J33 was originally developed by General Electric as a follow-on to their work with the designs of Frank Whittle during World War II. Their first engine was known as the I-A, but after major changes to adapt it to US production and to increase thrust, it started limited production as the I-16 in 1942, the 16 referring to its 1,600 lbf (7,100 N) thrust. Full production started as the J31 when the United States Army Air Forces introduced common naming for all their engine projects.
Along with the I-16, GE also started work on an enlarged version, known as the I-40. As the name implied, the engine was designed to provide 4,000 lbf / 18 kN (ending at 4,600 lbf (20 kN) with an additional low-altitude boost to 5,400 lbf / 24,000 N with water-alcohol injection). Design work started in mid-1943 and the first prototype underwent static testing on January 13, 1944.
Lockheed was in the midst of the XP-80 project at the time, originally intending to power their design with a US-produced version of the Halford H-1 of about 3,000 lbf (13 kN). Production of the H-1 ran into delays, and since the I-40 would dramatically improve performance, plans were made to fit the prototypes with the I-40 instead.
The I-40 became important to the USAAF’s plans when the I-16 powered P-59 was skipped over in favor of the I-40 powered P-80 as the US’s first production jet fighter. In 1945 the license to actually produce the engine was not given to General Electric, but Allison instead. Allison, working largely from government-owned wartime factories, could produce the engine in quantity more quickly and cheaply.
By the time the production lines were shut down Allison had built over 6,600 J33’s, and General Electric another 300 (mostly the early runs).
In 1958, surplus J33s were used in jet donkeys pushing dead loads at 200 knots to test aircraft carrier arresting gear cables and tailhooks at Lakehurst.
The General Electric/Allison J33 was a development of the General Electric J31, enlarged to produce significantly greater thrust, starting at 4,000 lbf (18 kN) and
The General Electric J31 was the first working jet engine produced in the United States and also the first jet engine to be produced in quantity there.
The J33 was originally developed by General Electric as a follow-on to their work with the designs of Frank Whittle during World War II. The J31 was essentially a production version of the prototype Whittle W.1 that had been sent to the US after the Tizard Mission successes. General Electric’s extensive experience in turbocharger production made them the natural choice for producing the engine, which they initially referred to as the I-16, I-A referring to the original prototype. After major changes to adapt it to US production and to increase thrust, it started limited production as the I-16 in 1942, the 16 referring to its 1,600 lbf (7,100 N) thrust. The United States Army Air Forces later decided to standardize all their jet engine naming, at which point the I-16 became the J31. Full production started as the J31.
Like the W.1, the I-16 produced 1,650 pounds force (7.3 kN) of thrust and weighed about 850 lb. Production started for the P-59 Airacomet in 1943, and by the time the lines shut down in 1945, a total of 241 had been built. GE also used the basic design to produce the much larger I-40 with 4,000 lbf, but this design was passed on to Allison as the J33, much to GE’s chagrin and another derivative of the J31, the General Electric I-20, given the military designation J39, was ordered but later cancelled.
Applications: Bell P-59 Airacomet Ryan FR Fireball Ryan XF2R Dark Shark
Specifications:
J31 Type: Centrifugal compressor turbojet Length: 72 in (1,828.8 mm) Diameter: 41.5 in (1,054.1 mm) Dry weight: 850 lb (385.6 kg) Compressor: Single-stage double-sided centrifugal Combustors: 10 reverse-flow can Turbine: Single-stage axial Fuel type: Kerosene (AN-F32) or 100/130 gasoline Oil system: pressure spray, wet sump with scavenge cooling and filtration, oil grade 60 S.U. secs (10.2 cs) at 38°C Maximum thrust: 1,650 lbf (7.33 kN) Overall pressure ratio: 3.8:1 Turbine inlet temperature: 1,220 °F (660.0 °C) Specific fuel consumption: 1.2 lb/lbf/hr (0.1223 kg/kN/hr) Thrust-to-weight ratio: 1.887 lbf/lb (0.018.5 kN/kg)
J-31-GE-1 Type: Centrifugal flow turbojet Length: ~72 in (1,828.8 mm) Diameter: ~41.5 in (1,054.1 mm) Dry weight: ~865 kg (1,910 lb) Compressor: Single-stage double-sided centrifugal flow Combustors: 10 reverse-flow can Turbine: Single stage axial flow Fuel type: Kerosene Maximum thrust: ~1,610 lbf (7.2 kN) Overall pressure ratio: ~4.5:1 Fuel consumption: ~1980 lb/hr (~898 kg/h) Specific fuel consumption: ~1.23 lb/hr/lb (~34.84 g/s·kN) Thrust-to-weight ratio: ~1.861:1
Designed for counter-Insurgency, the design and construction of the General Dynamics Charger took thirty-five weeks.
First flown on 25 November 1964, General Dynamics offered the Charger as an ‘off the shelf’ aircraft and claimed 100 could be delivered within 18 months. Orders of 500 would give an average price of $250,000.
During the 1950s, the general development of tactical aircraft moved in the direction of greater performance, at the expense of long field length, high cost and inflexibility. By 1959, USAF Tactical Air Command was ready to plan a new aircraft, in the first instance to replace the F 105, which would combine many new features and offer outstanding capability and versatility. In particular, it would be the first combat aircraft to have a variable sweep (so called ‘swing wing’) aerofoil to match the conflicting needs of high lift at takeoff or landing, low speed efficiency in subsonic cruise or loiter, and minimum-area minimum span shape for low level attack at the highest possible speed.
What caused great difficulty was that, in the first place, the TAC planners set their sights too high in drafting Specific Operational Requirement 183, so that the figures could not be met. Second, the US Navy in 1959 also wanted an important new aircraft, a Fleet Air Defense Fighter, carrying a powerful radar and long range missiles. In 1960, the new Secretary for Defense, Robert S McNarnara, studied the two requirements and, in his words, ‘was struck by the high degree of similarity’. After discussion with his civilian aides, he decided to urge that the USAF and Navy work towards a common aircraft design. His advisors suggested that such a move, called ‘commonality’, would save a billion dollars. After the longest and most hard fought procurement battle in history, General Dynamics Fort Worth won over Boeing¬ Wichita, the choice being announced on November 24, 1962. There had been an unprecedented four rounds of detailed technical and cost bidding, and in each round the consensus of customer opinion had, it was claimed, favoured Boeing. The Wichita team had not only offered what was in some respects a superior product, but they had consistently quoted a lower price. After Pentagon adjustments, the quotation for research, development and production of a total of 1726 aircraft (231 of them to be of the navy version) by Boeing was $5387 million and that from GD was $5803 million. As soon as the decision was announced, there was a storm of protest in Washington. It grew, as there was a prolonged public enquiry, and the position was later exacerbated by trouble with the winning aircraft and consistent failure to meet the impossible specification. GD flew the first F 111A on December 21, 1965, and on the second flight operated the wings through the whole range of sweep, from 16 degrees to 72.5 degrees, ahead of schedule. An attempt to win a further bonus by exceeding Mach 1 was thwarted by severe engine compressor stall. The chosen engine, the Pratt & Whitney JTF10A 20, later given the military designation TF30 P 1, had been selected because it was a typically conservative Pratt & Whitney product. It was likely to deliver the modest specified performance maxi¬mum thrust with full afterburner was only 8390 kg (18500 lb) and give little trouble. It was the world’s first afterburning turbofan, calculated to combine high performance in the supersonic dash mode with excellent fuel economy in the subsonic cruise regime. The new feature of afterburning in both the core and fan streams gave little difficulty, but the installed powerplant was a disaster. Part of the problem was that, to save weight, General Dynamics had cut the inlet ducts back under the wings, and turbulent air was hitting the aerodynamically tricky compressor. It took considerable redesign of the engine and a total redesign of the inlet system, with a so-called triple flow 3 inlet, before the installation would work properly in all flight regimes. Further extremely severe trouble was met with aircraft weight and drag, so that at first the specified range was not even approached. During 1965 66, using 18 development aircraft, the Fort Worth team restored some of the lost range by increasing the internal fuel capacity. This naturally raised the gross weight sharply, and accentuated the already marginally acceptable large size and weight of the F 111B Navy fighter version, co-producer of which was Grumman. After years of toil the F 111B came to an end in 1968 simply by the refusal of Congress to vote any further funds. This removed the captivating goal of commonality, leaving the F 111A not quite the way it would have been designed for the USAF alone. A further fundamental point is that, partly owing to confusion over the concept of a ‘fighter’, the F 111 had been planned to replace all the tactical aircraft of the USAF, including fighters, and attack bombers and fighters of the navy. In fact, the resulting aircraft was in no way a fighter, though with different radar and missiles it might have been a long range intercepter. Though it had been given an internal gun, a 20 mm (0.79 in) M61 Vulcan, with its ammunition drum occupying the internal weapon bay instead of bombs, this gun had no air combat role and was removed from most of the delivered aircraft. The F 111A was instead a bomber. Though the internal bay had been included to carry two B61 nuclear bombs at supersonic speed in a low level or high altitude attack, the main weapon load has always been hung externally. There are eight hard points on the wings, and all are on the swinging part; there are no pylons on the fixed gloves or fuselage. The outer pylons are seldom fitted, and a normal weapon load is 24 bombs (eight triplets) of a nominal 226 kg (500 lb) on the four inners, a true weight of 6314 kg (13920 lb). The F 111A can also carry a wide range of cluster bombs, dispensers, ALQ 119V ECM pods and other stores.
The F 111A was the first tactical aircraft to go into service with blind first pass strike capability. The equipment needed includes a large multi mode nose radar (in most versions, by General Electric), with two small dishes serving a terrain following radar (TFR). The right seater is an observer or weapons system officer, with comprehensive navigation and radar displays, and in the terrain following mode it is his job to keep the pilot constantly informed about obstructions or other objects coming up ahead.
The F-111 crew sits side-by-side, both are enclosed in a capsule which separates from the aircraft in an emergency, a proven escape system which obviates the need for ejection seats. In addition to 17 F-111As for development work, 141 went to the 4881 Tactical Fighter Squadron at Nellis AFB in July 1967, for intensive trials evaluation. With four tandem triplets of bombs, the maximum speed proved to be about 925 km/h (575 mph) at typical attack height; with two bombs in the weapon bay and nothing exter¬nal it was Mach 1.1, roughly according with SOR 183. At height the attainable speed in the clean condition was about Mach 2. Ferry range with six 2271 litre (500 Imperial gallons) drop tanks is about 6400 km (3980 miles). These were powered by two 8392kg afterburning thrust Pratt & Whitney TF30-P-3 turbofans. In March 1968, six F-111As of the wing’s 428th Tactical Fighter Squadron under Colonel Ivan H. Dethman were rushed to Takhli, Thailand, to begin combat operations against North Vietnam. The first three aircraft launched on the first three missions vanished for ever, although the detachment later flew 55 missions successfully. The USAF discovered, as a prisoner of war from this deployment would later confirm, that a tailplane problem caused uncontrollable pitch-up and roll. A separate fatique problem caused wing spar cracks and, in 1969, resulted in the loss of an F-111A when its wing was torn off. In 1969, the entire fleet of 300 aircraft was grounded while an exhaustive structural review programme remedied these problems. GD delivered 141 of the A model with TF30 3 engines, including two YF 111A air¬craft rebuilt from a cancelled British order for 50 F 111K. The Strategic Air Command’s FB-111A, operating with two wings, is a very long-range variant powered by two 9230kg afterburning thrust Pratt & Whitney TF30-P-7 turbofans, with modified inlets, long-span wing, and provision for nuclear or thermonuclear weapons or up to 50 340kg HE bombs; 76 FB-111As were built. The Royal Australian Air Force bought 24 F 111C with long span wings and stronger landing gears, these suffering a nine year delay due to structural problems and contract uncertainties and were delivered to Australia in 1973 after lengthy delays. The F-111C differs from the F-111A model in having a longer-span wing and stronger landing gear. Four F-111Cs have been converted to the reconnaissance role and the remainder, like many USAF ‘Aardvarks’, are being equipped with Pave Tack pods for laser acquisition of ground targets.
One of six RAAF F-111C at Red Flag 07
The Royal Australian Air Force operates three versions of the F-111:
the F-111C strike fighter
the unique RF-111C, modified for photo-reconnaissance work, and
ex-US Air Force F-111G’s, which help ensure Australia maintains its strike capability until the F-111 is retired.
The F-111D, F-111E and F-111F are variants of what has become a highly specialised long-range strike aircraft ideal as a counter to the Soviet Sukhoi Su-24 and as a means of hitting targets in eastern Europe from the British Isles. These variants are located respectively at Cannon AFB, New Mexico, RAF Upper Heyford and RAF Lakenheath, England. Production amounted to 96 F-111D, 94 F-111Es and 106 F-111Fs. The F-111H was a proposed strategic bomber once perceived as an ideal interim step for the 1980s when it appeared that the Rockwell B-1 had been cancelled. The F-111K was the intended version for the UK’s Royal Air Force. Neither was built, and total production amounted to 562 airplanes.
The F 111D, of which 96 were built, has the slightly more powerful 8891 kg (19600 lb) TF30 9 engine and the totally different ‘Mk II’ avionics, with mainly solid state digital circuits. The F 111E (94) had only improved engine inlets, otherwise resembling an A. The final F 111F version (106) has the vastly improved TF30-100 engine, rated at 11385 kg (25100 lb) thrust, and a simpler and cheaper version of the F 111D avionics. In 1967 some $118 million was spent in the development of a multi sensor reconnaissance pallet which was test flown in the eleventh F 111A. There remained an intention to rebuild some or all D models as RF-111Ds. Since 1976 much further development has been in progress to update this vital and powerful tactical attack force. Grumman has been developing the EF 111A electronic warfare aircraft by transferring the ALQ 99 tac jamming system of the EA 6B Prowler to rebuilt F 111A airframes. In 1965 McNamara, before leaving the Pentagon, announced that 210 strategic bomber versions designated FB-111A would be bought to replace Strategic Air Command’s B 58 and older B 52 bombers. Increased costs caused the eventual force to be terminated at only 76, and these equip two small (30 aircraft) wings, styled Bomb Wing (Medium), the 380th at Plattsburgh and 509th at Pease. The FB 111A has a modest engine, the 9230 kg (20350 lb) TF30 7, a so called ‘Mk 2B’ avionics system, and the long span wing and strong landing gear. It can carry a theoretical bombload of 50 free fall bombs of nominal 340 kg (750 lb), actually weighing a total of 18710 kg (41250 lb). 76 FB-111As were completed in 1971. Using the fuselage and intakes of the F-111E, the FB-111A introduced the larger wings designed by Grumman for the US Navy’s F-111B, plus uprated engines.
EF-111A
The EF 111A was born out of a series of studies undertaken during the late ’60s aimed at providing the USAF with a tactical EW system to replace its ageing fleet of EB 66 aircraft. The emergence of ALQ 99E tactical jamming system gave the green light for full scale airframe development and in January 1975, Grumman was awarded a $85.9 million contract for the construction of two prototype EF-111s. These aircraft were in fact preceded by an F 111A fitted with a ventral ‘canoe’ radome of the type proposed for the production models and which was used to test the aerodynamics of the installation together with five static air frames which were used in a series of electronic tests. The first fully aerodynamically representative prototype (AF serial 66 0049) made its maiden flight on 10th March, 1977 and was followed by a second aircraft (66 0041) which carried a complete electronic suite on 17 May 1977. Both aeroplanes were involved in an 84 flight company test programme and an 86 flight evaluation by the USAF. Surplus F 111A airframes were chosen for the programme and Grumman was assigned the task of converting the type into a dedicated EW platform.
In November 1979, full scale production of the EF 111A was sanctioned and the two prototypes were re worked to definitive standard. Aircraft number 049 reappeared on 19th June, 1981 and was initially retained by Grumman for further testing whilst 041 became the first ‘production’ air¬craft to be delivered to the USAF. Despite outward appearances, the EF-111A is a virtual re build of the original aircraft. During conversion, Grumman remove the wings and tail surfaces and strip the fuselage back to a basic keel structure. When the re build is complete, the original components have a fatigue life of approximately 8,000 hrs whilst the new features are rated for 10,000 hrs. The forward avionics bay remains unchanged and continues to carry the AN/APQ 160 navigation and the AN/APQ 110 terrain following radars which are standard to the F 111A. Aft of the radar boxes, a new oxygen converter has been installed along with a considerable quantity of new electronic equipment, the exact nature of which has not yet been cleared for publication. The basic geometry of the crew escape capsule is retained but the right hand side of the cockpit has been completely re built to house an electronic warfare officer (EWO) and his related controls. The pilot’s instrumentation remains essentially similar to that carried by the original aircraft but with some additions and re arrangement of individual items. The complete EF 111A cockpit layout is shown in the accompany¬ing illustration. Aft of the cockpit, the weapons bay has been extensively re worked to house the transmission and other elements of the Al Q 99. The installation takes the form of a pallet structure hung across the bay with nine transmitters attached to its underside and a range of related electronics above. What is known about the exact distribution of these items is shown in the accompanying inboard profile. Completing the weapons bay modifications is a 4.9m long canoe’ radome for the ALQ 99’s transmission antenna built into the underside of the bay doors. The electronics pallet is quoted as weighing 1,939kg with the ‘canoe’ adding a further 210kg, giving a total installation weight of 2,149kg. To provide power for the system, the original 60kVA engine mounted generators have been replaced with units rated at 90kVA. To cope with this increase, a new electrical sub system has been installed involving extensive re wiring. To cope with the heat output of the palletised ALQ 99, two new environmental control systems have been installed, namely the air cycling system from the F 111F and a refrigeration system to provide a constant 4.4 degrees C air flow for electronics cooling. The air cycling unit uses a ram air intake below the starboard main engine inlet duct and two exhausts mounted on either side of the rear of the under fuselage. The remaining modification of note concerns the vertical tail surface which has been re stressed to carry a fin top fairing and four side blisters designed to house a systems integrated receiver (SIR) group which is used to provide threat data for the various onboard EW systems. The fin top ‘pod’ is produced by Canadair and weighs, fully equipped, a respectable 432kg. An integral ‘glove’ is used to fair the installation into the vertical surface. The standard F 111A vent tank and HF antenna are retained within the fin structure. The EF-111A flew in production form on 28 June 1981. Production Ravens achieved an initial operational capability in November 1983 and entered service with a USAF unit in England in 1984. The 42nd and last was delivered in December 1985.
F-111A Engines: 2 x Pratt & Whitney TF30-P-3 turbofan 12.500/21,000 lb (5,670/9,525 kg). Wing span: 63 ft 0 in (19.20 m) fully forward, 31 ft 11.5 in (9.74 m) fully swept. Length: 73 ft 6 in (22.40 m). Height: 17 ft 1.5 in (5.22 m). Gross weight: approx 80,000 lb (36287 kg). Max speed: 1,650 mph (2,655 km/h) above 36,000 ft (11,000 m). Max range (internal fuel): 2,750 (4,425 km). Crew: 2.
EF-111A Engine: 2 x P&W TF30-P-3 turbofan, 18,500 lb thrust. Installed thrust: 164.6 kW. Wing span: 19.2-9.8 m (63-32 ft). Length: 23.16m. Height: 6.10m. Wing area: 48.8 sq.m Empty wt: 25,070 kg. MTOW: 40,340 kg. Max combat speed: 2,216 kph. Initial ROC: 5690 m / min. Service ceiling: 13,715 m. T/O run: 1350 m. Ldg run: 600 m. Fuel internal: 19,000 lt. Ferry range (on internal fuel): 3,706km. Unrefuelled endurance: 4 hr plus. Combat radius: 370-1,495km.
F-111B First fight: 18 May 1965. Wing span: 70 ft. Length: 67 ft 6 in
FB-111 Span: 72.5deg 10.34 m (33 ft 11 in); 16deg sweep 21.34 m (70 ft) Length: (with probe) 23.1 m (75 ft 9.5 in) Gross weight: (after in flight refuelling) 55747 kg (122900 lb) Maximum speed: (Sea level, clean, most versions) 1346 km/h (836 mph, Mach 1.1); (high altitude, clean) 2335 km/h (1450 mph, Mach 2.2)
FB-111A Engines: 2 x Pratt & Whitney TF30-P-7 turbofan, 20,350 lb / 9231 kg thrust. Wingspan: 70 ft 0 in / 21.34 m Wingspan swept: 33 ft 11 in / 10.34 m Length: 73 ft 6 in / 10.34 m Height: 17 ft 1.5 in / 5.22 m MTOW: 114,300 lb / 51,846 kg Speed: 1650 mph / 2655 kph Ceiling: 60,000 ft / 18,290 m Range: 2925+ mi / 4707+ km Armament: six SRAM missiles (or nuclear bombs) or up to 37,500 lb (17,010 kg) of conventional bombs. Crew: 2
F-111C Engine: Two Pratt and Whitney TF-30 turbofans (9,500 kg thrust each) 21.3m extended, 10.3m swept Sweep: 72.5-16deg Length: (with probe) 23.1 m (75 ft 9.5 in) Height: 5.3m Basic Weight: 24,000kg Gross weight: 51846 kg (114300 lb) Maximum speed: (Sea level, clean, most versions) 1346 km/h (836 mph, Mach 1.1); (high altitude, clean) 2335 km/h (1450 mph, Mach 2.2) Crew: 2
RF-111C Wing span: 19.2 m / 9.8 m (63-32 ft).
F-111D Span: 72.5deg sweep 9.74 m (31 ft 11.5 in); 16deg sweep 19.2 m (63 ft) Length: (with probe) 23.1 m (75 ft 9.5 in) Gross weight: 41958 kg (92500 lb) Maximum speed: (Sea level, clean, most versions) 1346 km/h (836 mph, Mach 1.1); (high altitude, clean) 2335 km/h (1450 mph, Mach 2.2)
F-111E Span: 72.5deg sweep 9.74 m (31 ft 11.5 in); 16deg sweep 19.2 m (63 ft) Length: (with probe) 23.1 m (75 ft 9.5 in) Gross weight: 41958 kg (92500 lb) Maximum speed: (Sea level, clean, most versions) 1346 km/h (836 mph, Mach 1.1); (high altitude, clean) 2335 km/h (1450 mph, Mach 2.2)
F-111F Span: 72.5deg sweep 9.74 m (31 ft 11.5 in); 16deg sweep 19.2 m (63 ft) Length: (with probe) 23.1 m (75 ft 9.5 in) Gross weight: 45360 kg (100000 lb) Maximum speed: (Sea level, clean, most versions) 1346 km/h (836 mph, Mach 1.1); (high altitude, clean) about Mach 2.5.
