Harrier GR.1 Specifications:
- Power Plant: 1 × Rolls-Royce Pegasus 101 turbofan, 19,000 lbf
- Range: 1,200 miles
- Max Speed: 735 mph
- Ceiling: 49,200 ft.
- Guns: 2× 30 mm (1.18 in) ADEN cannon pods under the fuselage
- 1 Under-fuselage & 4 Under-wing Hardpoints: 4 x Mantra rocket pods or 4 x AIM-9 Sidewinder missiles or 2 x AS-37 Martel missiles, bombs (up to 5,000 lbs.) or 2 x drop tanks
Hawker Siddeley Harrier - Development:
In the mid-1950s, Michel Wibault began discussing the concept of a directable fan jet engine with NATO's Mutual Weapons Development Project. Approaching Bristol Engine Company, they entered into talks regarding combining the firm's Orpheus and Olympus jet engines into one capable of directable thrust. As this project began to yield positive results, Bristol contacted Sydney Camm at Hawker Aviation about designing an aircraft to use the new type of engine. Though defense funding was minimal, NATO possessed a requirement for a Light Tactical Support Fighter and Camm saw an opportunity.
Moving forward with private funding, Hawker worked to combine the new Pegasus engine with a workable airframe. Supported by testing a NASA, Camm refined the design. This resulted in the company, now Hawker Siddeley, approving the construction of two prototypes in early 1959. Dubbed P.1127, the project received further support late that year when the Ministry of Supply contracted for a pair of prototypes. The first of these was completed in July 1960 and flew on its own for the first time on November 19. Utilizing the directable fan jet Pegasus, the prototypes worked to achieve vertical take offs and landings (VTOL).
As P.1127 testing yielded results, nine evaluation aircraft, dubbed Kestrel FGA.1, were ordered. Delivered in early 1964, these equipped the Tripartite Evaluation Squadron formed at RAF West Raynham in Norfolk. Flown by British, American, and West German pilots, the Kestrel proved the concept. Though Hawker had begun designing a supersonic version of the Kestrel, the P.1154, it was dropped in 1965 when the Royal Air Force elected to move forward with an improved variant of the P.1127. Entering into pre-production a year later, the new type was named Harrier in 1967.
Hawker Siddeley Harrier - Engine Design:
While earlier attempts at VTOL aircraft had focused on rotors and direct jet thrust, the Harrier's Pegasus engine took a different route which utilized vectored thrust. Using four rotating engine nozzles, two on each side of the aircraft, the pilot could direct the engine's thrust. These nozzles moved from 0° (horizontal) down to 98° (vertical/slightly forward). For VTOL operations, the nozzles would be set to 90° allowing it to rise like a helicopter. At the desired altitude, the nozzles were moved to horizontal to allow for level flight. Due to the nature of the system, the aircraft could also hover.
As a result of the advanced and unique engine system, Harrier pilots were required to be highly skilled in both helicopter and fixed wing flying. The former was needed to handle the VTOL component as the Harriers reaction control system for maintaining stability was similar to a helicopter's cyclic control. Though largely used in the takeoff and landing procedures, thrust vectoring could also be used in combat to make the aircraft highly agile and capable of maneuvers that could not be accomplished in a traditional fighter.
Introduced in to RAF service in 1969, the GR.1 type soon received an upgrade to GR.1A with the arrival of improved Pegasus engines. This type evolved into the GR.3 which contained an enhanced sensor package and engine. The definitive model of the Harrier, the GR.3 was altered for service with the Royal Navy by British Aerospace. The resulting Sea Harrier entered service in 1980. Two years later, the Harrier first entered combat when it played a key role in the British victory during the Falklands War. Flying from the Royal Navy carriers HMS Hermes and HMS Invincible, they provided cover and struck targets ashore.
Assessed by the United States, the Harrier was purchased for service with the US Marine Corps as the AV-8A Harrier. Flying from land and assault ships, the USMC Harriers fulfilled ground-attack, close air support, reconnaissance, and fighter roles. The type was also sold to the Spanish Navy under the designation AV-8S Matador. A number of the Spanish aircraft were later sold to Thailand. In the 1980s, development began on a successor to the Harrier. This program resulted in the larger Harrier II and AV-8B. As these newer aircraft began to arrive, the first generation of Harriers were retired from service.
At this time, only Thailand continues to operate first generation Harriers. The newer aircraft saw combat during the 1991 Gulf War. While the USMC continues to fly the AV-8B, the RAF and Royal Navy are in the process of retiring their Harriers in anticipation of receiving the new Lockheed F-35 Lightning II.