British Aerospace (Hawker Siddeley) Harrier
From Scramble - The Aviation Magazine
|BAE Systems (Hawker Siddeley) Harrier|
|First Flight||31 August 1966|
|Length||13.90 m||45 ft 7 in|
|Wingspan||7.70 m||25 ft 3 in|
|Height||3.45 m||11 ft 4 in|
|Wing area||18.67 m²||201 ft²|
|Empty||5530 kg||12190 lb|
|Loaded||7830 kg||17260 lb|
|Maximum takeoff weight||11500 kg||25350 lb|
|Engines||one Rolls-Royce Pegasus turbofan|
|Thrust||84.5 kN||19000 lbf|
|Maximum speed||1185 km/h||735 mph|
|Service ceiling||15000 m||49200 ft|
|Rate of climb||m/min||ft/min|
The development of the Harrier started in the late 1950s and culminated in the Hawker P.1127. The P.1127 was a light prototype with a simple wing design, to test the engine concept and stability. The engine, the Rolls-Royce Pegasus, is a unique concept, with its four movable exhausts and many other small exhausts (JCV: Jet Control Valve) in several places in the fuselage for manoeuvrability. The wingtip holds retractable struts with small support wheels. During the test phase the first modifications were made: new v-shaped stabilizers and a modified wing. The next step was the Kestrel FGA1 in 1963. The Kestrel had a longer fuselage, a new swept wing, bigger tail plane and the engine exhausts were relocated. The Harrier was later developed into the Harrier II. The 2nd generations Harrier is described in a separate article.
All first generation Harriers and Sea Harriers were built in the UK, mainly at the Kingston factory, with major components supplied by the Brough and Hamble sites of Hawker Siddeley/BAe. First flights were all from Dunsfold. Harrier II production was divided between the UK and USA, with final assembly and flight testing of most aircraft being at the McDonnell Douglas plant at St.Louis, Missouri. RAF Harrier IIs were mostly assembled at Kingston and flown from Dunsfold, with the exception of the thirteen T10 trainers, which were assembled and flew from Warton. Rolls-Royce at Bristol supplied all the Pegasus engines, with around 25% of components for USMC Harrier IIs being supplied by Pratt & Whitney.
After the formation of the Hawker Siddeley company the aircraft was renamed to Harrier and the RAF ordered 78 Harrier GR1s in 1967, which were delivered from 1969. These were powered with the Pegasus 6 Mk.101, with a thrust of 19,000lbs. From 1971 on, they received the Pegasus 10 Mk.102 with a thrust of 20,500lbs. These Harriers were designated Harrier GR1A and are externally the same as the GR1. A total of 61 GR1s were built, as well as 10 T2s, not counting the two T2 prototypes and a single "Mark 52" two-seat Harrier, which had the tailcode "G-VTOL" and was retained by Hawker Siddeley for their own purposes. The Pegasus Mk.103 was the engine for the GR3, and these were also externally equal to the Harrier GR1. When they became available, the GR1/A also received the Mk.103, and were re-designated Harrier GR3.
The need arose for a trainer version. The Harrier T2 was developed from the Harrier GR1 and first flew 1969. It differs widely from the original since the fuselage was lengthened by 47 inches and the second ejection seat was raised by 11 inches. The canopy consisted of three parts: the windscreen, and two hinged parts, opening to the right. Mounted in between the two ejection seats is a see through screen, to protect the rear pilot. The fuselage was stretched a further 33 inches near the tail section and the tail plane was heightened 11 inches by raising the base. During testing this was deemed to little and from the eleventh T2 it was raised a further 18 inches. This modification was also applied to earlier Harrier T2s. Later the Harrier T2 received the Pegasus Mk.102 and became the Harrier T2A.
To increase the combat capabilities of the Harrier, in 1975 it received a 20,500 lbs rated Pegasus 11 Mk.103 and Ferranti 106 LRMTS. This instrument could either be locked onto a target to provide continuous updates on position and rate of closure via laser radar, with the result displayed on the cockpit HUD; or could be used as what is now known as a "laser spot tracker", locking onto a target being illuminated by ground troops or whoever with a laser target designator. Another visible change was a Marconi ARI-18223 RWR, whose forward aerial appeared as a tab breaking up the smooth curve of the tailfin. The rearward aerial was placed less obtrusively on the tailcone. A total of 50 Harrier GR1s and Harrier GR1As were upgraded to GR3 and 40 new aircraft were ordered. During the Falklands war in 1982 some Harrier GR3s were equipped with chaff dispensers below the tail and a sensor pod in between the gun pods. Also a I-band RWR was fitted below its laser nose.
With the Harrier GR3 entering service some of the T2s received the laser nose and RWR and were re-designated Harrier T4. They also were fitted with the Mk.103. The Royal Navy used modified RAF T4s designated T4N. It is recognizable by the absence of the laser nose, but it does have the RWRs. India received to T4(I)s. which were modified to T60 standard.
With the Sea Harrier FA2s a new trainer version was developed. Externally the same as the T4N but with FA2 avionics, these were designated Harrier T8.
Export designation for 1st generation single seat Harriers.
Export designation for 1st generation two-seat Harriers. India ordered 2+2 two seat Harrier T60s for Sea Harrier training.
Sea Harrier FRS1
Due to its VTOL capabilities, the Royal Navy became interested in the Harrier. With these capabilities, it was possible to operate from warships without large flight decks. Developed from the GR3, the Sea Harrier FRS1 first took to the air in 1978. It had a redesigned nose, to fit the Ferranti Blue Fox radar (earlier Harriers did not have a radar) and a raised ejection seat. Other small differences include a raised pitot and the nose camera shifted from left to right side. The FRS1 was also fitted for the use of the Sidewinder, at first only on the outer wing pylons. During the Falklands war this became two Sidewinders per pylon. India also bought the Sea Harrier, 6+10 aircraft designated Sea Harrier FRS51.
Sea Harrier FA2
The Royal Navy felt the need for a Harrier with a bigger radar range and beyond-visual range missiles, due to experiences in the Falklands war. It was decided to upgrade the FRS.1 to Sea Harrier. FRS2. The model redesignated Sea Harrier F/A2, later Sea Harrier FA2. It had the Blue Vixen radar and the Pegasus Mk.106, a navalised Pegasus Mk.105 as fitted to the GR5. With the bigger radar the nose was no longer pointy but more rounded. The fuselage was lengthened just behind the wing with 13 ¾ inch, the pitot was moved to the tail and the wingspan was increased slightly with new wingtips. 33 FRS.1s were modified to FA2 15 new airframes were ordered. The first aircraft was delivered on 2 April 1993 and the first operational deployment was in April 1994 as part of the UN force in Bosnia. The final new-build Sea Harrier FA2 was delivered on 18 January 1999. The Sea Harrier was withdrawn from service in 2006 and the last remaining aircraft from 801 Naval Air Squadron were decommissioned on 29 March 2006, the MoD stating that significant expenditure would be required to upgrade the fleet for only six years of service until introduction of the F-35B Lightning II. This left the Royal Navy carriers (again) without air-defence capabilities.
Although the US Marine Corps had a strong interest in VTOL aircraft, as noted, the USMC did not participate in the Tripartite Evaluation Squadron. However, when the US took ownership of six Kestrel FGA1s - designated XV-6A - from the TES, some of them also ended up at the Naval Air Test Center at Patuxent River, Maryland, where the Marines performed evaluations on them. In April 1966, the US Marines operated a Kestrel off the commando assault ship Raleigh and were impressed with the aircraft. Nonetheless, the Kestrel had no combat capability and was useless to the Marines as it was, and there matters stood until the Farnborough Air Show in the UK in September 1968. Three Marine Corps officers dropped into the Hawker Siddeley chalet at Farnborough and asked to fly the Harrier. The three were given ten flights each, and felt the Harrier was what they were looking for. What the Marines required was a strike aircraft that could support landing forces. Fleet carriers had to be kept well at sea for their own safety, but Harriers could fly from smaller assault ships just offshore, or from rough landing sites behind the battle lines, to provide rapid strikes for ground troops. The main obstacle was that the Harrier was a British machine, and the US armed forces have a strong preference to "buy American". The solution was for Hawker Siddeley to license the aircraft to McDonnell Douglas for sale to the USMC AV-8A. Rolls-Royce, who had bought out Bristol in the interim, similarly made an arrangement to allow Pratt & Whitney to build the Pegasus under license, which then became a Pratt & Whitney F402. These collaborations were to be crucial to the future of the Harrier. In practice, although the original agreement envisioned that McDonnell Douglas would actually build the Harriers themselves, none of the AV-8As, or Mk.50 as Hawker Siddeley designated them, were actually made in the US, since opening a second assembly line proved uneconomical. They were built in the UK, shipped as airfreight overseas, and delivered by MDD. It is unclear if McDonnell Douglas fitted the aircraft with USMC avionics. The first few AV-8As used the Pegasus 10, but all following production used the Pegasus 11.
The US forces had also gotten interested in the Harrier. 110 GR3s with Pegasus Mk.103 were ordered (8 of them trainers) and introduced in the US Marine Corps as the AV-8A (export version Harrier Mk.50, initially designated AV-6B) in 1971. Externally the only difference was the long VHF antenna on the fuselage near the wing. Spain also ordered two batches of Harriers, a total of 11 single seat and 2 two seat aircraft. These were designated AV-8A(S) (Harrier Mk.55). During the Franco regime these came from the US, and later they came directly from the UK. These aircraft were similar to the AV-8A and the only big difference was a second antenna in front of the large VHF antenna. Later modifications included a RWR in the tail but not in the fuselage end. With the introduction of the EAV-8B in the Spanish Navy, these aircraft became obsolete and were sold, together with a carrier, to Thailand at the end of the 1990s.
The TAV-8A trainer (Harrier Mk54) was the American version of the RAF T4 (without the laser nose and tail RWR) with the Pegasus Mk.103 engine. Export model delivered to Spain was designated TAV-8A(S) (Harrier Mk.56).
In 1982 the AV-8C became operational. This was a variant of the AV-8A with some of the modifications for the AV-8B (Harrier II), which was under development at the time. Biggest modifications were the RWRs fitted at the end of the fuselage and the wingtips. Some 47 AV-8As were modified to AV-8C, often in multiple stages.
Harrier T4N of the Royal Navy
Harrier GR3 of 1 Squadron at Eindhoven
AV-8A of the Spanish Navy at Landivisiau
RAF Harrier GR1 at Bundeswehr museum, Gatow