The FB-111A & F-111A Flight Tests

FB-111A and F-111A Flight Tests.

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The photos and comments on this pages are provided by CMSgt Jim Rusch (Ret.) who served at Plattsburgh and Pease AFB from October 1977 until August 1988.

Aircraft with the wings swept back approximately 50 degrees. Note the weapons pylons on stations 4 and 5 pivot, to remain parallel with the fuselage as the wings sweep back and forth. But there were definite size limits to the weapons that could actually be carried on these two inboard wing stations, to prevent crushing them into the fuselage with wings swept full aft (72.5 degrees). There ís a mechanical locking device on the wing sweep handle (located on the pilot's left side, just under the outboard canopy rail), to prevent sweeping the wings beyond a certain point, with certain weapons on board (or tanks on stations 2 and 7, which do not pivot a all with wing sweep). On more than one occasion (i.e. during Alert pre-cock-on ground tests), the aircrew inadvertently swept the wings with these restricted weapons on board, causing serious damage to the aircraft and weapons (and sometimes even to the fuel tanks on stations 2 and 7).

Here the FB-111A has its wings tucked in the full aft (72.5 degree sweep) position. Note that the weapons pylons on stations 4 and 5 are still parallel, and extremely close to the fuselage (engine intakes). Any weapons still on board would have contacted the fuselage.

Flight testing of the BRU-3/A (Bomb Release Unit) on stations 4 and 5, while loaded with 6 each 500lb practice bombs (Note the blue bands on the bomb shapes, indicating INERT weapon shapes). In the late 1980ís, the FB-111 were equipped with the BRU-3/A racks to add a true conventional capability to the aircraft. Note the flight test marking decals on the rear of the aircraft, along the engine panels, just above the ventral fins (which were used to reduce the tendency of the aircraft to oscillate (aka fishtail) inflight).

Flight testing of 4 SRAM (AGM-69A Short-Range Attack Missiles) loaded on stations 3, 4, 5, and 6. Note the aerodynamic tailcone fairing attached to the rear of each SRAM, just behind the three moveable control surfaces on the missile. These fairings were only used on external SRAM loads. The dark blue and spotted decals on the SRAM, pylons, and aircraft fuselage were used during flight testing, so chase aircraft and on-board cameras could detect even the slightest movement during loads testing, or weapons separation testing. With precise measurements, any unwanted movement toward the host aircraft, or flutter can be discovered and hopefully resolved. Also note that this particular flight test aircraft has extended aerodynamic fairings on its aft-facing pods, between the horizontal stabilizers and the engine nozzles. Production aircraft did not have these smooth fairings, but had flat surfaces instead, that housed some aft-looking sensors.

FB-111A 67-7192 flying with four drop tanks, on stations 2, 3, 6, and 7.

Intentional fuel dump, from the fuel dump mast located between the TF-30 engine nozzles (aka tail feathers, or turkey feathers) and then lit on fire for the burn. The fuel is dumped first, and then ignited by selecting afterburner on one, or both engines. When done at night, this activity usually resulted in UFO reports from near and afar.

An operational FB-111 launching a SRAM (AGM-69A Short-Range Attack Missile). The SRAM would free-fall a certain distance from the aircraft, before the solid rocket motor was designed to ignite. The SRAM could also be jettisoned from the aircraft, and then the rocket motor would never fire at all. To accomplish either of these, there was a small lanyard with a ìDî ring, inserted on top of the missile (along the raceway just aft of the umbilical connector), that would either fall with the missile (causing a jettison, and no rocket motor), or be kept by the MHU-140 Missile Ejector Rack. If a magnetic solenoid in the MHU-140 was engaged, it captured the ìDî ring, and as the missile was forcibly ejected by the MHU-140 kicker feet, the lanyard was pulled out of the top of the missile. This was part of an activation sequence that included missile squibs firing (to free the control surfaces, activate the 2-part chemical battery, etc), and eventually the rocket motor igniting. If this lanyard fell with the missile, the missile merely fell to earth too.

An operational FB-111 launching a SRAM (AGM-69A Short-Range Attack Missile), probably over White Sands Missile Range in New Mexico. This range was often used for live launch missions, called 'Bullet Blitz.' During a Bullet Blitz, the 2-stage, solid rocket motor was taken out of normal stockpiles, but the warhead (W-69 or SLTP) was replaced with an OTP (Operational Test Payload) that had certain onboard instrumentation, and a self-destruct capability in the unlikely event that the missile wandered way off course. With an OTP on the missile, a special control panel had to be installed in the cockpit (far right-hand side), with this command-destruct switch installed.

This production FB-111 launches an external SRAM (AGM-69A Short-Range Attack Missile), while the aircraftís wings are swept full-aft (72.5 degrees). Note the 'old' SAC paint scheme, SRAM with aerodynamic tail cone still on station 4, and weapons bay doors closed.

An operational FB-111 taking JP-4 (aka passing gas at 30,000 feet) from either a KC-135A (probably) or a KC-135Q. Both had the J-57 motors with water injection, though the 'Q' models had the high-speed boom, and separate internal tanks for JP-7 for refueling the SR-71s.
Sad note: Tanker 57-1418 was upgraded, and re-engined with the CFM-56 motors, making her a KC-135R model. Unfortunately in April 1999, she was written off as total loss after a textbook Class A mishap, involving the usual 'ìchain of events'. During a ground test at Tinker AFB, OK, a routine ground pressurization check went very bad, and wrecked the entire rear fuselage, blowing parts of the aircraft hundreds of yards away. During previous maintenance, the cabin pressure relief valves were secured shut and never released afterwards. With only a couple of pounds per square inch of pressure, and no relief in sight, she done blowed up big time. There are photos available on the internet of the damage done, and it's clear why she was written off as a total loss.

Almost anyone that was ever at Pease or Plattsburgh has seen this photo. This was the official FB-111 lithograph that was signed and then framed, and given to people as they PCS'd (Permanent Change of Station) from Pease or Plattsburgh. In this photo the air refueling door is fully open (directly behind the pilot's helmet), and there are four SRAM (AGM-69A Short-Range Attack Missiles) on stations 3, 4, 5 and 6. Also of interest, is the flat, round, black plate, just aft of the upper nose radome, and forward of the center windscreen frame. This plate is actually clear glass, and was a part of the Astro-tracker system, which was another on-board navigation system used on the FB-111. The Astro-tracker could triangulate three celestial bodies (stars, sun, moon), and determine the relative position of the aircraft. It is very similar to navigators on ships (and KC-135s) that used a sextant, and astronomical tables to compute sight angles, into stars into longitude and latitude measurements. The Astro-tracker did this automatically, without the paper volumes of astronomical tables and such.

Flight testing of 6 fuel tanks, on stations 2, 3, 4, 5, 6, and 7.

Early flight test FB-111, with instrumented pitot boom way out in front of the aircraftís bow wave (to increase the accuracy of airspeed, AOA and yaw readings). Also note the white nose radome. Operational aircraft had the black nose radome, housing the attack radar system antenna dish, and both of the smaller terrain-following radar dishes (left and right channels).

Flight testing of 6 fuel tanks. Each tank could be jettisoned if necessary, by an explosive gas generator that would cause the tank pylon to separate. The inboard tanks on stations 3, 4, 5 and 6 all pivoted with the wing sweep angle to ensure that the tanks stayed parallel to the fuselage as the wings swept aft or forward. The outboard two tanks, on stations 2 and 7 did not pivot at all, and were fixed. Therefore these tanks were actually a bit ìtoe inî 6 degrees with the wings full forward, and had to be jettisoned before the wings could be swept further aft than in this photo. In all my years at Plattsburgh and Pease (1977-1989), I never saw an operational configuration with 6 fuel tanks like this photo.

Early flight test of the FB-111ís conventional weapons carrying capability. Each BRU-3/A (Bomb Release Unit) could carry six 500 pounders, and the FB-111 could carry 4 BRU-3/A racks (thatís 12,000 pounds of conventional munitions carried on the external wing stations 3, 4, 5 and 6). Note the extended pitot tube boom, and instrumented AOA and yaw vanes installed. Also note the vertical red line below the leading edge of the horizontal stabilizer. This red line indicates the plane-of-rotation for the TF-30 jet engineís turbine wheel. The theory is that if the engine is going to catastrophically fail, and come flying apart, it will probably do so along the plane-of-rotation of the turbine wheel. On the FB-111, this could cause the other engine to be damaged too, so on the F-14, the engines were separated even more so, and contained in separate engine pods for safety.

Early flight test bird, 66-0057, with white paint, white radome, and extended flight test pitot tube boom. Wings are tucked into the full aft, 72.5 degree position, for minimum drag (parasitic and induced drag).

Early flight test bird, 66-0057, with white paint, white radome, and extended flight test pitot tube boom. Note the four brown, side-looking antennae, located just forward of the cockpit (crew escape capsule), and below the blackened area in front of the windscreens (this blackened area was painted to reduce the glare coming off the long nose of the aircraft).

One of the earlier flight tests of the SRAM (AGM-69A Short-Range Attack Missile), configured for external carriage on stations 4 and 5 (with the aerodynamic tailcone fairing installed to reduce drag). The fuel tanks on stations 2, 3, 6, and 7 are all parallel to the fuselage, indicating the wings are not full forward (20 degrees) but are swept back to 26 degrees. If at 20 degrees (full forward), the tanks on 2 & 7 (outboard pair) would point slightly toe-in 6 degrees, as these two stations did not pivot at all with wing sweep.

An FB-111A inflight, with wing stations empty. The FB-111 had a longer and stronger wing than the ìnormalî F-111 aircraft. The leading edge slats, and trailing edge flaps on the FB-111 had 5 sections, whereas the F-111 had only 4 sections.

From below, flight testing of the B-43 bomb shape (BDU-35s I think) on stations 4 and 5, with fuel tanks on stations 2, 3, 6, and 7, wings swept to 26 degrees. Note the extended pitot boom used for flight testing, to get more accurate airspeed data well in front of the bow wave of the aircraft, especially in the transonic/supersonic speed region. There are also instrumented AOA and yaw vanes mounted on this special pitot boom.

This aircraft has two fuel tanks on stations 3 and 6, and two B-61 shapes (BDU-38s I think) on stations 4 and 5. Note that there is no room on these inboard pylons for any weapons much fatter than these B-61 shapes. Also note how close the horizontal stabilizers are to the aft wingtip sections.

Flight testing of the SRAM (AGM-69A Short-Range Attack Missiles) on stations 4 & 5 with installed aerodynamic tailcones, and B-43 shapes (BDU-35s I think) on stations 3 & 6, and non-pivoting fuel drop-tanks on stations 2 and 7 (no stores or tanks on stations 2 & 7 pivoted with wing sweep). Also note all the orange on board the aircraft, indicating flight test equipment only, and the instrumented pitot boom (extended further forward of the bow wake than a productions pitot boom, and with the instrumented AOA and Yaw vanes attached).

Flight testing of 4 SRAM (AGM-69A Short-Range Attack Missiles) loaded on stations 3, 4, 5, and 6. Note the aerodynamic tailcone fairing attached to the rear of each SRAM. These fairings were only used on external SRAM loads (and SRAM with these fairings wouldnít even fit into the FB-111Aís weapons bay). These fairings would be blown off upon ignition of the SRAMís 2-stage, solid rocket motor. Also note that this particular flight test aircraft has extended aft-facing pods, between the horizontal stabilizers and the engine nozzles.

This bomber has a SRAM (AGM-69A Short-Range Attack Missile) loaded in station 'R' of the weapons bay, and an instrumentation package (the orange box) loaded on station 'L' of the weapons bay (the weapons bay stations were not numbered, but referred to as Left and Right). When loaded internally, the SRAM could not have the aerodynamic tailcone fairing, that was needed for carriage on external stations. Note the small triangular doors at the very front of the weapons bay. These were called 'retreat doors' and improved the airflow up and into the weapons bay, to help get the weapon out quickly and cleanly. Prior to these retreat doors being installed, at high-speed deliveries, the weapon sometimes 'bounced' off the fast-moving air stream and rattled around inside the weapons bay for way too long. Even though the MHU-140 Missile Ejector Rack forcibly kicks the missile downward, it wasn't enough to guarantee the missile (or bomb) would leave the bay and free fall until the rocket motor ignited. Note also the brown bands on the SRAM rocket motor; indicating it is indeed a live 2-stage, solid rocket propellant motor. At Pease and Plattsburgh, the payload section (on the very front of the missile) was usually flown as an SLTP (Simulated Launch Training Payload), Inert, without any explosive components whatsoever. The rocket motor was still real, and the same one that might be sitting on Alert the very next day, without and major modification. In the Load Training operation, only INERT rocket motors were used.

Here the fixed pylons on stations 2 and 7 are clearly evident. These two wing stations do not pivot at all with wing sweep, and with the wings full forward (at the 20 degree setting), the tanks'ìtoe-in' 6 degrees. The pylons on stations 3, 4, 5, and 6 all pivot with wing sweep, and stay parallel to the fuselage. Note the rear pods, between each engine ís tail feathers and the horizontal stabilizers. On operational aircraft, these pods were flat (as shown), and housed aft-looking sensors. Also in the rear of the vertical tail, at the very top, is a 'crystal ball' which is also another aft-facing sensor, used to detect infrared heat signatures.

An FB-111A flying beneath a brilliant sun, carrying fuel tanks on stations 2, 3, 6, and 7, and B-43 shapes on stations 4 and 5.

Above the clouds.

69-6503 Departs Pease AFB, Runway 34, carrying some 500lb training shapes (note the blue coloring, indicating that they are inert munitions).

A B-43 training shape (BDU-35 I think) is being tested on station 4, with the aircraft in the WLT (Weapons Load Training) hangar. The load team member appears to be checking physical clearances between the shape and the fuselage as the wing is swept aft. Note the flaps/slats are full up (required for any wing sweeping). Also note the bent silver tube with red 'Remove Before Flight' streamer in the middle of tank pylon on station 3. This tube is a ground safety device, and is used to vent the expanding gases of a gas generator (which is intended to jettison the pylon with tank attached, in an emergency). Whenever the aircraft was on the ground, but especially while in WLT (where testing 'External Stores Jettison' was common), these safety devices had to be installed. Anyone that was around the FB-111 any length of time can tell stories of inadvertent activation of these gas generators, sometimes with full fuel tanks ending up on the ground. My first incident was when prepping an Alert aircraft at Plattsburgh, when the cockpit crew hit the 'External Stores Jettison' switch, and all four tanks hit the ramp, hard. And then in the shelter we heard 'But I thought you installed the shorting plugs'.

Flight test FB-111 with four SRAM externals, on stations 3, 4, 5 and 6. Note the orange special instrumentation hardware located on the air louvers, just aft of the right-seater. These air louvers ingested air, and routed it to each engine, to provide a secondary air source for each engine intake. Jet engines cannot ingest air above the speed of sound, so the air had to be slowed down to subsonic speeds prior to the first stage compressor blades. While flying at supersonic speeds, the FB-111 used a combination of an expandable ìspikeî in each intake, which was used to restrict and therefore slow the incoming air to subsonic, and the air from these louvers, so the TF-30 engines would continue to operate with subsonic intake air, and continue to run normally.

	The photos and comments on this pages are provided by CMSgt Jim Rusch (Ret.) who served at Plattsburgh and Pease AFB from October 1977 until August 1988.
Aircraft with the wings swept back approximately 50 degrees. Note the weapons pylons on stations 4 and 5 pivot, to remain parallel with the fuselage as the wings sweep back and forth. But there were definite size limits to the weapons that could actually be carried on these two inboard wing stations, to prevent crushing them into the fuselage with wings swept full aft (72.5 degrees). There ís a mechanical locking device on the wing sweep handle (located on the pilot's left side, just under the outboard canopy rail), to prevent sweeping the wings beyond a certain point, with certain weapons on board (or tanks on stations 2 and 7, which do not pivot a all with wing sweep). On more than one occasion (i.e. during Alert pre-cock-on ground tests), the aircrew inadvertently swept the wings with these restricted weapons on board, causing serious damage to the aircraft and weapons (and sometimes even to the fuel tanks on stations 2 and 7).
Here the FB-111A has its wings tucked in the full aft (72.5 degree sweep) position. Note that the weapons pylons on stations 4 and 5 are still parallel, and extremely close to the fuselage (engine intakes). Any weapons still on board would have contacted the fuselage.
Flight testing of the BRU-3/A (Bomb Release Unit) on stations 4 and 5, while loaded with 6 each 500lb practice bombs (Note the blue bands on the bomb shapes, indicating INERT weapon shapes). In the late 1980ís, the FB-111 were equipped with the BRU-3/A racks to add a true conventional capability to the aircraft. Note the flight test marking decals on the rear of the aircraft, along the engine panels, just above the ventral fins (which were used to reduce the tendency of the aircraft to oscillate (aka fishtail) inflight).
Flight testing of 4 SRAM (AGM-69A Short-Range Attack Missiles) loaded on stations 3, 4, 5, and 6. Note the aerodynamic tailcone fairing attached to the rear of each SRAM, just behind the three moveable control surfaces on the missile. These fairings were only used on external SRAM loads. The dark blue and spotted decals on the SRAM, pylons, and aircraft fuselage were used during flight testing, so chase aircraft and on-board cameras could detect even the slightest movement during loads testing, or weapons separation testing. With precise measurements, any unwanted movement toward the host aircraft, or flutter can be discovered and hopefully resolved. Also note that this particular flight test aircraft has extended aerodynamic fairings on its aft-facing pods, between the horizontal stabilizers and the engine nozzles. Production aircraft did not have these smooth fairings, but had flat surfaces instead, that housed some aft-looking sensors.
FB-111A 67-7192 flying with four drop tanks, on stations 2, 3, 6, and 7.
Intentional fuel dump, from the fuel dump mast located between the TF-30 engine nozzles (aka tail feathers, or turkey feathers) and then lit on fire for the burn. The fuel is dumped first, and then ignited by selecting afterburner on one, or both engines. When done at night, this activity usually resulted in UFO reports from near and afar.
An operational FB-111 launching a SRAM (AGM-69A Short-Range Attack Missile). The SRAM would free-fall a certain distance from the aircraft, before the solid rocket motor was designed to ignite. The SRAM could also be jettisoned from the aircraft, and then the rocket motor would never fire at all. To accomplish either of these, there was a small lanyard with a ìDî ring, inserted on top of the missile (along the raceway just aft of the umbilical connector), that would either fall with the missile (causing a jettison, and no rocket motor), or be kept by the MHU-140 Missile Ejector Rack. If a magnetic solenoid in the MHU-140 was engaged, it captured the ìDî ring, and as the missile was forcibly ejected by the MHU-140 kicker feet, the lanyard was pulled out of the top of the missile. This was part of an activation sequence that included missile squibs firing (to free the control surfaces, activate the 2-part chemical battery, etc), and eventually the rocket motor igniting. If this lanyard fell with the missile, the missile merely fell to earth too.
An operational FB-111 launching a SRAM (AGM-69A Short-Range Attack Missile), probably over White Sands Missile Range in New Mexico. This range was often used for live launch missions, called 'Bullet Blitz.' During a Bullet Blitz, the 2-stage, solid rocket motor was taken out of normal stockpiles, but the warhead (W-69 or SLTP) was replaced with an OTP (Operational Test Payload) that had certain onboard instrumentation, and a self-destruct capability in the unlikely event that the missile wandered way off course. With an OTP on the missile, a special control panel had to be installed in the cockpit (far right-hand side), with this command-destruct switch installed.
This production FB-111 launches an external SRAM (AGM-69A Short-Range Attack Missile), while the aircraftís wings are swept full-aft (72.5 degrees). Note the 'old' SAC paint scheme, SRAM with aerodynamic tail cone still on station 4, and weapons bay doors closed.
An operational FB-111 taking JP-4 (aka passing gas at 30,000 feet) from either a KC-135A (probably) or a KC-135Q. Both had the J-57 motors with water injection, though the 'Q' models had the high-speed boom, and separate internal tanks for JP-7 for refueling the SR-71s. Sad note: Tanker 57-1418 was upgraded, and re-engined with the CFM-56 motors, making her a KC-135R model. Unfortunately in April 1999, she was written off as total loss after a textbook Class A mishap, involving the usual 'ìchain of events'. During a ground test at Tinker AFB, OK, a routine ground pressurization check went very bad, and wrecked the entire rear fuselage, blowing parts of the aircraft hundreds of yards away. During previous maintenance, the cabin pressure relief valves were secured shut and never released afterwards. With only a couple of pounds per square inch of pressure, and no relief in sight, she done blowed up big time. There are photos available on the internet of the damage done, and it's clear why she was written off as a total loss.
Almost anyone that was ever at Pease or Plattsburgh has seen this photo. This was the official FB-111 lithograph that was signed and then framed, and given to people as they PCS'd (Permanent Change of Station) from Pease or Plattsburgh. In this photo the air refueling door is fully open (directly behind the pilot's helmet), and there are four SRAM (AGM-69A Short-Range Attack Missiles) on stations 3, 4, 5 and 6. Also of interest, is the flat, round, black plate, just aft of the upper nose radome, and forward of the center windscreen frame. This plate is actually clear glass, and was a part of the Astro-tracker system, which was another on-board navigation system used on the FB-111. The Astro-tracker could triangulate three celestial bodies (stars, sun, moon), and determine the relative position of the aircraft. It is very similar to navigators on ships (and KC-135s) that used a sextant, and astronomical tables to compute sight angles, into stars into longitude and latitude measurements. The Astro-tracker did this automatically, without the paper volumes of astronomical tables and such.
Flight testing of 6 fuel tanks, on stations 2, 3, 4, 5, 6, and 7.
Early flight test FB-111, with instrumented pitot boom way out in front of the aircraftís bow wave (to increase the accuracy of airspeed, AOA and yaw readings). Also note the white nose radome. Operational aircraft had the black nose radome, housing the attack radar system antenna dish, and both of the smaller terrain-following radar dishes (left and right channels).
Flight testing of 6 fuel tanks. Each tank could be jettisoned if necessary, by an explosive gas generator that would cause the tank pylon to separate. The inboard tanks on stations 3, 4, 5 and 6 all pivoted with the wing sweep angle to ensure that the tanks stayed parallel to the fuselage as the wings swept aft or forward. The outboard two tanks, on stations 2 and 7 did not pivot at all, and were fixed. Therefore these tanks were actually a bit ìtoe inî 6 degrees with the wings full forward, and had to be jettisoned before the wings could be swept further aft than in this photo. In all my years at Plattsburgh and Pease (1977-1989), I never saw an operational configuration with 6 fuel tanks like this photo.
Early flight test of the FB-111ís conventional weapons carrying capability. Each BRU-3/A (Bomb Release Unit) could carry six 500 pounders, and the FB-111 could carry 4 BRU-3/A racks (thatís 12,000 pounds of conventional munitions carried on the external wing stations 3, 4, 5 and 6). Note the extended pitot tube boom, and instrumented AOA and yaw vanes installed. Also note the vertical red line below the leading edge of the horizontal stabilizer. This red line indicates the plane-of-rotation for the TF-30 jet engineís turbine wheel. The theory is that if the engine is going to catastrophically fail, and come flying apart, it will probably do so along the plane-of-rotation of the turbine wheel. On the FB-111, this could cause the other engine to be damaged too, so on the F-14, the engines were separated even more so, and contained in separate engine pods for safety.
Early flight test bird, 66-0057, with white paint, white radome, and extended flight test pitot tube boom. Wings are tucked into the full aft, 72.5 degree position, for minimum drag (parasitic and induced drag).
Early flight test bird, 66-0057, with white paint, white radome, and extended flight test pitot tube boom. Note the four brown, side-looking antennae, located just forward of the cockpit (crew escape capsule), and below the blackened area in front of the windscreens (this blackened area was painted to reduce the glare coming off the long nose of the aircraft).
One of the earlier flight tests of the SRAM (AGM-69A Short-Range Attack Missile), configured for external carriage on stations 4 and 5 (with the aerodynamic tailcone fairing installed to reduce drag). The fuel tanks on stations 2, 3, 6, and 7 are all parallel to the fuselage, indicating the wings are not full forward (20 degrees) but are swept back to 26 degrees. If at 20 degrees (full forward), the tanks on 2 & 7 (outboard pair) would point slightly toe-in 6 degrees, as these two stations did not pivot at all with wing sweep.
An FB-111A inflight, with wing stations empty. The FB-111 had a longer and stronger wing than the ìnormalî F-111 aircraft. The leading edge slats, and trailing edge flaps on the FB-111 had 5 sections, whereas the F-111 had only 4 sections.
From below, flight testing of the B-43 bomb shape (BDU-35s I think) on stations 4 and 5, with fuel tanks on stations 2, 3, 6, and 7, wings swept to 26 degrees. Note the extended pitot boom used for flight testing, to get more accurate airspeed data well in front of the bow wave of the aircraft, especially in the transonic/supersonic speed region. There are also instrumented AOA and yaw vanes mounted on this special pitot boom.
This aircraft has two fuel tanks on stations 3 and 6, and two B-61 shapes (BDU-38s I think) on stations 4 and 5. Note that there is no room on these inboard pylons for any weapons much fatter than these B-61 shapes. Also note how close the horizontal stabilizers are to the aft wingtip sections.
Flight testing of the SRAM (AGM-69A Short-Range Attack Missiles) on stations 4 & 5 with installed aerodynamic tailcones, and B-43 shapes (BDU-35s I think) on stations 3 & 6, and non-pivoting fuel drop-tanks on stations 2 and 7 (no stores or tanks on stations 2 & 7 pivoted with wing sweep). Also note all the orange on board the aircraft, indicating flight test equipment only, and the instrumented pitot boom (extended further forward of the bow wake than a productions pitot boom, and with the instrumented AOA and Yaw vanes attached).
Flight testing of 4 SRAM (AGM-69A Short-Range Attack Missiles) loaded on stations 3, 4, 5, and 6. Note the aerodynamic tailcone fairing attached to the rear of each SRAM. These fairings were only used on external SRAM loads (and SRAM with these fairings wouldnít even fit into the FB-111Aís weapons bay). These fairings would be blown off upon ignition of the SRAMís 2-stage, solid rocket motor. Also note that this particular flight test aircraft has extended aft-facing pods, between the horizontal stabilizers and the engine nozzles.
This bomber has a SRAM (AGM-69A Short-Range Attack Missile) loaded in station 'R' of the weapons bay, and an instrumentation package (the orange box) loaded on station 'L' of the weapons bay (the weapons bay stations were not numbered, but referred to as Left and Right). When loaded internally, the SRAM could not have the aerodynamic tailcone fairing, that was needed for carriage on external stations. Note the small triangular doors at the very front of the weapons bay. These were called 'retreat doors' and improved the airflow up and into the weapons bay, to help get the weapon out quickly and cleanly. Prior to these retreat doors being installed, at high-speed deliveries, the weapon sometimes 'bounced' off the fast-moving air stream and rattled around inside the weapons bay for way too long. Even though the MHU-140 Missile Ejector Rack forcibly kicks the missile downward, it wasn't enough to guarantee the missile (or bomb) would leave the bay and free fall until the rocket motor ignited. Note also the brown bands on the SRAM rocket motor; indicating it is indeed a live 2-stage, solid rocket propellant motor. At Pease and Plattsburgh, the payload section (on the very front of the missile) was usually flown as an SLTP (Simulated Launch Training Payload), Inert, without any explosive components whatsoever. The rocket motor was still real, and the same one that might be sitting on Alert the very next day, without and major modification. In the Load Training operation, only INERT rocket motors were used.
Here the fixed pylons on stations 2 and 7 are clearly evident. These two wing stations do not pivot at all with wing sweep, and with the wings full forward (at the 20 degree setting), the tanks'ìtoe-in' 6 degrees. The pylons on stations 3, 4, 5, and 6 all pivot with wing sweep, and stay parallel to the fuselage. Note the rear pods, between each engine ís tail feathers and the horizontal stabilizers. On operational aircraft, these pods were flat (as shown), and housed aft-looking sensors. Also in the rear of the vertical tail, at the very top, is a 'crystal ball' which is also another aft-facing sensor, used to detect infrared heat signatures.
An FB-111A flying beneath a brilliant sun, carrying fuel tanks on stations 2, 3, 6, and 7, and B-43 shapes on stations 4 and 5.
Above the clouds.
69-6503 Departs Pease AFB, Runway 34, carrying some 500lb training shapes (note the blue coloring, indicating that they are inert munitions).
A B-43 training shape (BDU-35 I think) is being tested on station 4, with the aircraft in the WLT (Weapons Load Training) hangar. The load team member appears to be checking physical clearances between the shape and the fuselage as the wing is swept aft. Note the flaps/slats are full up (required for any wing sweeping). Also note the bent silver tube with red 'Remove Before Flight' streamer in the middle of tank pylon on station 3. This tube is a ground safety device, and is used to vent the expanding gases of a gas generator (which is intended to jettison the pylon with tank attached, in an emergency). Whenever the aircraft was on the ground, but especially while in WLT (where testing 'External Stores Jettison' was common), these safety devices had to be installed. Anyone that was around the FB-111 any length of time can tell stories of inadvertent activation of these gas generators, sometimes with full fuel tanks ending up on the ground. My first incident was when prepping an Alert aircraft at Plattsburgh, when the cockpit crew hit the 'External Stores Jettison' switch, and all four tanks hit the ramp, hard. And then in the shelter we heard 'But I thought you installed the shorting plugs'.
Flight test FB-111 with four SRAM externals, on stations 3, 4, 5 and 6. Note the orange special instrumentation hardware located on the air louvers, just aft of the right-seater. These air louvers ingested air, and routed it to each engine, to provide a secondary air source for each engine intake. Jet engines cannot ingest air above the speed of sound, so the air had to be slowed down to subsonic speeds prior to the first stage compressor blades. While flying at supersonic speeds, the FB-111 used a combination of an expandable ìspikeî in each intake, which was used to restrict and therefore slow the incoming air to subsonic, and the air from these louvers, so the TF-30 engines would continue to operate with subsonic intake air, and continue to run normally.