Piper PA-48 Enforcer
Piper Aircraft has received a USAF contract, expected to total about $12 million, to design, develop and test two new prototypes of the Enforcer as a lightweight close-support aircraft. The Enforcer, powered by a 2,445 ehp Lycoming T55-L-9 turboprop, was developed in 1971 as part of the activities of Cavalier Aircraft Corporation, which had produced a batch of updated North American F-51 Mustangs for export and evolved the Turbo Mustang III with a Dart engine. Piper acquired rights in the Enforcer in 1970 after Cavalier had developed the prototype, and for another 8 years Piper lobbied Congress to force the USAF to officially re-evaluate the Enforcer.
The two new prototypes were conversions of existing F-51 airframes, and modified by Piper at its Lakeland, Florida, plant. As well as the T55 installation, they feature wing-tip tanks to increase total fuel capacity to 424 US gal (1605 1t), six wing strong points to carry two podded General Electric GAU-8 30-mm four-barrel cannon, 2.75-in (7-cm) unguided rockets or bombs, and aerodynamic improvements that include changes in the aileron control system and a 19-in (48-cm) extension of the rear fuselage, with enlarged tailplane and elevators. With a gross weight of 14,000 lb (6 350 kg), the Enforcer was expected to have a max speed of 350 kts (648 km/h). The USAF five-month evaluation is expected to be conducted in the late summer of 1983 and completed by February 1984, embracing 98 flights.
In 1971 Piper built two Enforcers by heavily modifying two existing P-51 Mustang aircraft and fitting them with Lycoming T55-L9A turboprop engines (along with numerous other significant modifications). One airframe was single seat (called the PE-1 and FAA registered N201PE) and the other was a dual-control aircraft (called the PE-2, registered N202PE). Prior to the PAVE COIN evaluation, N202PE was lost in a crash off the Florida Coast.
The Piper PA-48 Enforcer flew for the first time on April 9 1971 from the company's Lakeland, Florida, facility.
The Enforcer that flew is powered by a 2,445-shp Avco Lycoming T55-L-9 turboprop, turning a Skyraider propeller cut down by Piper from 14 feet to 11 feet, 6 inches in diameter. The fuselage has been stretched by 19 inches between the cockpit and fin; the fin area has been increased by nine percent, mostly in chord but slightly in height; the rudder is now equipped with a yaw stability augmentation system; and the tailplane/elevator area has been enlarged by 36 percent. Tip tanks provide 1,900 pounds of fuel capacity, in addition to some wing bending relief and end-plate effect.
To ease stick loads at high speed and low level, the Enforcer’s ailerons are equipped with a boost system from a Lockheed T-33. The landing gear embodies Grumman G-1 wheels, T-39 Sabreliner brakes and Mustang-type tires, and the tailwheel retracts. With six under-wing pylons, the Enforcer's main armament will be a pair of pod mounted 30mm General Electric four-barrel rotary cannons capable of firing at a rate of 2,400 rounds per minute (40 rounds per second). Other weaponry could include miniguns, rockets and cluster bombs.
On the Enforcer's first flight, the entire mission was flown in the takeoff and landing configura-tion to examine its stability, controllability and handling. Tests on the second flight included gear retraction, a climb to 20,000 feet and acceleration to 300 knots.
Eventually in the 1979 defense bill $11.9 million was allocated for Piper to build two new prototypes and for the USAF to perform another flight evaluation. Since the Enforcer was never in the Air Force inventory, it was not given an official military designation and did not receive an Air Force serial number. Instead, it carries the Piper designation PA-48 and Federal Aviation Administration (FAA) registration numbers N481PE and N482PE.
By the time the PA-48s were completed, they shared less than ten percent of their structure with the P-51. The two PA-48s were tested during 1983 and 1984 at Eglin AFB, Florida, and Edwards AFB, California. As in the PAVE COIN tests of 1971, the PA-48s were found to perform well in their intended role, but the USAF again decided not to purchase any.
Of the prototype aircraft produced, three of the four still exist. The original PE-1 is disassembled and in storage. One of the PA-48s, N482PE, awaits restoration at Edwards Air Force Base. N481PE has been fully restored and resides in the 'Prototype Hangar' at the National Museum of the United States Air Force at Wright-Patterson Air Force Base near Dayton, Ohio.
Engine: 1 x Lycoming T55-L-9 turboprop, 1831kW
Max take-off weight: 6350 kg / 13999 lb
Wingspan: 12.60 m / 41 ft 4 in
Length: 10.40 m / 34 ft 1 in
Height: 4.00 m / 13 ft 1 in
Wing area: 37.9 sq.m / 407.95 sq ft
Max. speed: 650 km/h / 404 mph
Ceiling: 11465 m / 37600 ft
Range: 1480 km / 920 miles