The Final Mission: The USAF’s QF-4 Target Drones

Without being seen, USAF aircraft lands on the road behind the Phantom and fires an air-to-air missile. The F-4 attacks aggressively in hopes of evading the missile and retaliating at all times. But it’s no use – tracking flawlessly, the missile cuts the F-4 in half. The resulting fireball rains debris, but there are no parachutes.

What is happening? Why is just one US fighter being shot down by another? Strange as it sounds, this is a normal day for its 82 Aerial Target Squadron (ATRS). The 82nd flies the USAF’s last active-duty Phantoms as full-scale aerial targets (FSATs) for firearms tests.

They Shoot Airplanes, Don’t They?

Under United States law (Title 10, Section 2366 of this U.S. Code) a missile system must undergo lethality testing before it could enter full-scale manufacturing. This means it must be fired at a combat-configured target, fully capable aircraft.

The price and hazards of using a manned aircraft from the active-duty inventory for this purpose are obvious. Instead, the target is the unmanned FSAT drone.

In service of U.S. test and evaluation actions, Phantom drones also act as goals for non-lethal tests of missiles, radar and other sensors, and defensive systems. They also encourage Air Force and Navy training, for example, “Combat Archer” missile shoots.

Both services also use sub-scale goal drones, which are less costly to operate than FSATs. However, just a full-scale target delivers the flight features, performance envelope — such as subsonic and supersonic flight at altitudes up to and over 50,000 feet — endurance, radar, and infrared (IR) signatures, and damage resistance of an actual aircraft.

The F-4 proved to be a logical choice to succeed the QF-106. Countless surplus Phantoms were available following the form’s phase-out. Its suitability for drone usage had been demonstrated from the Navy, which had operated QF-4s in its own drone application since 1972. And since the QF-106 had suffered several accidents because of landing-gear failure, the F-4s’s ruggedness and reliability have been selling points.

Over 230 Phantoms have been “droned” since 1995, and conversions will likely continue through 2011 if all contract options are exercised. Production initially focused on F-4E strategic fighters and F-4G “Wild Weasel” defense-suppression aircraft. As the past models retired from active duty, these airframes were in good shape and had a military supply chain.

The earliest conversions included several RF-4C photo-reconnaissance variants, which were found more difficult to control than later models because they lacked pliers. Nonetheless, without the suitable F-4Gs stocks and left of candidate F-4Es depleted, RF-4C conversions declared in 2007.

Candidate aircraft are taken from storage at the Aerospace Maintenance and Regeneration Group, in Davis-Monthan Air Force Base (AFB), Arizona. Following depot maintenance, the aircraft has flown into Mojave, where the drone conversion is performed. The procedure takes about seven months from storage at AMARG to active status and prices about $800,000 in the U.S. per aircraft.

The Making of a Drone

The QF-4 conversion provides a digital control system for remote operation of the aircraft’s steering, throttles, flaps, landing gear, brakes, braking parachute, and tailhook. Also fitted are a vector Doppler scoring system, second autopilot, GPS and transponder formation-keeping in remote flight. Non-essential gear such as the F-4E’s 20-mm cannon is replaced with ballast, while unused avionics such as radar are abandoned aboard but handicapped. At length, the wingtips and tail are painted orange to differentiate the aircraft for a drone.

The QF-4s are delegated to the 82nd ATRS at Tyndall, a portion of the 53rd Weapons Evaluation Group. The squadron operates full-scale and sub-scale drones over Tyndall’s air weapons range from the Gulf of Mexico.

Flying the QF-4

Both 82 ATRS and Det 1 keep a few “primary flier” aircraft for manned flight, accepted for up to 300 flight hours. Other FSATs are cleared for 100 hours and are kept ready for unmanned flight with non-essential things like ejection seats removed, or stored in non-flying storage.

Despite having over 60 aircraft on strength, 82 ATRS includes tiny military personnel: six USAF pilots divide between both foundations and a couple of sergeants to oversee maintenance. The other personnel is civilians employed by Lockheed Martin, such as pilots, ground controls, and maintainers. All are ex-military with a tremendous degree of experience — as an instance, contract pilots typically have over 1000 F-4 flying hours.

QF-4s are always flown with a pilot aboard unless your weapons release will happen. Usually, he fails to touch the controls but stands ready to take over if ground control is dropped or the aircraft departs. The pilots fly the aircraft themselves chase missions and to maintain proficiency.

Drone controls have a flight instrument display on a monitor, but no immediate visual contact with the aircraft. A controller may fly using a joystick and, keyboard instead of a pole, throttles, and rudder pedals; however, most test and evaluation flights have been steered by computer. This allows a test to be flown within exact parameters and replicated precisely if necessary.

The programmed flight trail may incorporate an automatic landing, but if the telemetry signal is degraded or the aircraft has been damaged, a Ground Mobile Control System (GMCS) is utilized to perform a visual landing. GMCS is a panel van with two hands positions on the roof. It’s parked by the end of the runway so the controllers can observe the aircraft as they steer it. One controller controls pitch and throttles, while the other controllers heading and bank. Two controllers are needed as a result of workload — where an onboard pilot will sense the aircraft’s speed and altitude, the controls must interpret it from instruments.

Missile vs. Aircraft

Normally, a number of practice runs precede an evaluation mission, to confirm that all test parameters are being fulfilled — lots of trial runs are less expensive than one failed evaluation. If a missile will be fired at the drone, the actual test will use a NULLO (Not Beneath Live Local Operation) aircraft but is also Latin for “zero,” the amount of crew aboard. The NULLO aircraft takes a destruct charge (that the warhead from an AIM-9 missile) to be sure the jet’s demise if it’s damaged during the evaluation or control, is lost.

Accompanied by a manned chase airplane, the drone has been launched in the 7,000×300-foot “droneway” in Tyndall or the 11,000×300 foot at Holloman, heading south to avoid populated regions. In Tyndall, two DeHavilland Canada E-9A aircraft are found as well. These converted Dash-8 airliners utilize sideways-looking airborne radar to establish a “haul box” which won’t endanger civilian ships on the water beneath the Gulf Range.

To prevent the weapon system under test, the drone flight profile may include defensive maneuvers (including 6-G turns and vertical maneuvers), chaff and flare releases, and radar. If the drone is destroyed, its wreckage falls upon the range. But when it succeeds along with the chase pilot confirms it’s undamaged, the aircraft has been recovered at the foundation. A straight-in approach is made of the south together with the hook, and the aircraft is stopped by an arresting cable.

A NULLO drone will usually complete three or four missions before being destroyed. Except during a lethality test, the missiles fired may lack warheads along with the drone’s flight trail might be programmed to prevent an immediate strike. This saves the cost of replacing the drone and prolongs the life of this QF-4 inventory. The drone’s onboard scoring system will inform if the missile attained “kill” parameters. Sometimes a lethality evaluation will fail to take down the aircraft, an occurrence that confirms the significance of Title 10 testing.

“Live fire” jobs for Tyndall’s QF-4s have included Operational Test and Evaluation (OT&E; -RRB- of Raytheon’s AIM-9X Sidewinder and AIM-120 AMRAAM missiles. But more than missiles are tested: a Holloman QF-4 has flown growth evaluations of the BAE Systems Common Missile Warning System, which can identify surface-to-air missiles found at an aircraft and mechanically release suitable countermeasures.

QF-4 pilots are fond of the aircraft and do not delight in seeing one depart on a one time, final assignment. But they’re philosophical about the loss, noting, “It’s a better way for an aircraft to die than rotting away from the ‘boneyard’ or on a pole. The taxpayer is now getting his money’s worth from these types of aircraft.” After 13 decades, the amount of F-4 airframes in AMARG that may be droned without excess rework is shrinking. Moreover, the QF-4’s capability to represent the operation and signatures of contemporary fighter aircraft decreases with every new design that appears. The QF-4’s successor as a full-scale target looks set to be the QF-16, starting around 2014.

Heritage Flight

While on evaluation duties, QF-4 drones are rarely seen away in their Tyndall and Holloman foundations. But the men and women who fly and maintain the Phantoms are very proud of the aircraft, the past operational US tactical fighter in the Vietnam era.

In 2004, 82 ATRS personnel sought to bring the QF-4 into the USAF’s Heritage Flight program, to fulfill a gap in historic policy between World War Two and Korean War warbirds and modern fighters. Six QF-4Es were repainted in camouflage schemes from the F-4’s operational service. Following USAF approval, they participate in Heritage Flight formations at some airshows on each shore in 2005. In 2006, the QF-4s received Heritage Flight financing from Air Combat Command — that the 2005 flights were funded from the 53 WEG operating budget! — permitting the QF-4s to look at approximately 20 shows. As well, a simple QF-4 solo screen pattern was introduced.

Except because of their camouflage, the Heritage Flight QF-4Es is standard “primary flier” drones and is employed for normal 82 ATRS surgeries when not in airshows. Since the first six aircraft started to run out of flight hours in 2007, a new batch was painted. These aircraft all wear the same Southeast Asia strategy to simplify maintenance.

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