Monday, November 9, 2009


The Hawker P.1127 and the Hawker Siddeley Kestrel FGA.1 were the development aircraft that led to the Hawker Siddeley Harrier, the first VSTOL jet fighter-bomber.

In 1957, the Bristol Engine Company informed Sydney Camm of Hawker that they had a project to combine their Olympus and Orpheus jet engines to produce a directable fan jet, an idea brought to them via NATO's Mutual Weapons Development Project (MWDP) Team from the French engineer Michel Wilbault.  Hawker took the planned engine, which became known as the Pegasus, as a basis for a plane that could meet the current NATO specification for a Light Tactical Support Fighter  This was a time of deep UK defence cuts, detailed in the 1957 Defence White Paper; as a result, Hawker's had to seek commercial funding and significant engine development funding came from the USA. Much model testing was done by NASA at Langley Field for the project.  Hawker test pilot Hugh Merewether went to the US at NASA's request to fly the Bell X-14. In March 1959, the company's board of directors (now Hawker Siddeley) decided to fund two P.1127 prototypes. Then the UK Ministry of Supply contracted for two P.1127 prototypes in late 1959.

The first prototype P.1127, serial XP831 was delivered in July 1960 for static engine testing, and in October the Pegasus flight engine was made available. The first tethered flight took place the same month and free flight hover achieved on 19 November, after which the first publicity photos were released. The second prototype made its first take off conventionally on 7 July 1961. The two aircraft proceeded to "close the gap" between vertical take off and flight, achieved by 8 September.
Four more prototypes were ordered. Throughout this period improved Pegasus engines were being developed, with the Pegasus 3 being capable of 15,000 lbf (67 kN) of thrust. Apart from this, the first four aircraft were quite similar, but the fifth, XP980 introduced the taller fin and tailplane anhedral seen on the Harrier.  The fourth machine was used, in part to give the Hawker production test pilots P.1127 familiarisation.  The first carrier vertical landing was performed by the first prototype on HMS Ark Royal in 1963. The last P.1127, XP984, introduced the swept wing. It was eventually fitted with the 15,000 lbf (66.7 kN) Pegasus 5 and functioned as the prototype Kestrel.
The first three P.1127s were lost, the second and third during development. The first prototype crashed at the Paris Air Show in 1963. All the pilots involved survived.

Kestrel FGA.1

Hawker Siddeley XV-6A Kestrel in USAF livery
Nine  evaluation aircraft were ordered as the Kestrel FGA.1, an improved version of the P.1127, the first flying on 7 March 1964. The Kestrel had fully swept wings and a larger tail than the early P.1127s, and the fuselage was modified to take the larger 15,000 lbf (85 kN) Pegasus 5 engine as in the P.1127/Kestrel prototype XP984.
Due to interest from the US and Germany, the Tri-partite Evaluation Squadron (TES) was formed on 15 October 1964 at RAF West Raynham, staffed by military test pilots from Britain, the US and West Germany.[10] During testing one aircraft was lost;  and evaluations finalised in November 1965.
Six of the eight surviving evaluation aircraft (the three allocated to US plus those allocated to Germany) were transferred to the USA  for evaluation by the Army, Air Force, and Navy (but not the US Marine Corp) as the XV-6A Kestrel. After Tri-Service evaluation they were passed to the USAF for further evaluation at Edwards Air Force Base, except for two that were assigned to NASA.
One of the two remaining British based Kestrels was attached to the Blind Landing Experimental Unit (BLEU) at RAE Bedford and the other, XS693, went to Blackburn's for modification to take the uprated Pegasus 6 engine.  In addition to some strengthening, there were alterations to the air intake, which had throughout the P.1127 and Kestrel series featured an inflatable lip to smooth the intake airflow when the aircraft was almost stationary. There were concerns about the Service life of these devices, so they were replaced with conventional suction relief doors.  This aircraft became the prototype for pre-production Harriers.

  P.1127 (RAF)

NATO requirement NBMR-3 specified for a VTOL aircraft, but one that was expected to have the performance of an aircraft like the F-4 Phantom along with the VTOL capability. Hawker drafted the P.1150, a supersonic P.1127 and the P.1154 which would meet NBMR-3. The latter was a winner of the NATO competition and development continued until cancelled at the point of prototype construction in 1965. The RAF then began looking at a simple upgrade of the Kestrel  as the P.1127 (RAF).
In late 1965, six pre-production P.1127 (RAF) aircraft were ordered by the RAF (actually the remaining number from Kestrel order).  The first pre-production aircraft flew on 31 August 1966. The aircraft was named Harrier in 1967.

General characteristics
  • Crew: 1
  • Length: 42 ft 6 in (12.95 m)
  • Wingspan: 22 ft 11 in (6.99 m)
  • Height: 10 ft 9 in (3.28 m)
  • Empty weight: approximately 9,800 lb (4,445 kg)
  • Loaded weight: for VTO 14,500 lb (6,580 kg)
  • Max takeoff weight: for STO, approximately 17,000 lb (7,700 kg)
  • Powerplant: 1× Bristol Siddeley Pegasus 5 vectored-thrust turbofan, 15,000 lbf (67 kN)
  • Maximum speed: 710 mph, Mach 0.92 (1,142 km/h) at sea level
  • Service ceiling: (service) approximately 55,000 ft (1,675 m)
  • Rate of climb: approximately 30,000 ft/min (150 m/s)
  • Thrust/weight: 1.04

Atar Volant, avión raro

The original Atar Volant or C.400 P1 was a turbojet engine produced by SNECMA (Société National d'Etude et de Construction de Moteurs d'Aviation) engineers, as part of their 'Atar' series. Encased in a basic fairing which could hold fuel and remote-control equipment, the unit weighed 5,600 pounds (2550 kg)[1] and generated a thrust of approximately 6,200 pounds-force (27.6 kN); the Atar Volant was able to cause vertical lift, which was precisely its purpose. There were later Atar Volant models, each made improvements and alterations to the previous designs, and eventually resulted in a fully-fledged craft.

The Coléoptère was a VTOL or 'Vertical Take-Off and Landing' aircraft that was designed by SNECMA during the 1950s. While the Coléoptère was not the first VTOL aircraft, none of its predecessors had an annular wing designed to land vertically. The benefit of this annular wing was the requirement for very little landing or take-off space. However, the design of the Coléoptère met with many problems, such as overcoming the torque imparted to a vertical engine by its own turbine wheels and rotating compressor, and discovering and developing a method of balancing the craft on the column of air released from its jet pipe during the take-off and landing phase, as well as, more particularly, during manoeuvres out of the vertical positioning. To address some of these problems, as well as to provide a way to achieve vertical lift, SNECMA set to work on what was to become the first model of the Atar Volants.

There were at least four Atar Volant models constructed, each improving or making alterations on the last: the first (C.400 P.1), C.400 P.2, C.400 P.3. and the last, the C.450-01. The second in the series had much success at an international air display in Le Bourget, in Paris, and the third became a full-scale coleopter in its own right, due to numerous improvements and alterations made to the model. The C.450-01 model's maiden flight took place in May 1959. Two months later, while being put through its paces, the single prototype crashed. The pilot was seriously injured, and the prototype wrecked, resulting in the abandoning of its development and the project.

Boeing 707

The Boeing 707 is a four-engine commercial passenger jet airliner developed by Boeing in the early 1950s. Its name is most commonly pronounced as "Seven Oh Seven". Boeing delivered a total of 1,010 Boeing 707s, and also offered a smaller, faster model of the aircraft that was marketed as the Boeing 720.

Although it was not the first commercial jet in service, the 707 was among the first to be commercially successful. Dominating passenger air transport in the 1960s, and remaining common throughout the 1970s, the 707 is generally credited with ushering in the Jet Age.[3][4] It established Boeing as one of the largest makers of passenger aircraft, and led to the later series of aircraft with "7x7" designations.

The 707 was an outgrowth of the Boeing Model 367-80. The "Dash 80" took less than two years from project launch in 1952 to rollout on May 14, 1954 and first flight on July 15, 1954. This was powered by the Pratt & Whitney JT3C engine, which was the civilian version of the J57 used on many military aircraft of the day, including the F-100 fighter and the B-52 bomber.

The prototype was conceived as a proof of concept aircraft for both military and civilian use: the United States Air Force was the first customer for the design, using it as the KC-135 Stratotanker midair refueling platform. It was far from certain that the passenger 707 would be profitable. At the time, Boeing was making nearly all of its money from military contracts: its last passenger transport, the Boeing 377 Stratocruiser, had netted the company a $15 million loss before it was purchased by the Air Force as the KC-97 Stratotanker.[5]

The 132-inch (3,350 mm) fuselage of the Dash 80 was only wide enough to fit two-plus-two seating (in the manner of the Stratocruiser). Answering customers demands and under Douglas competition, Boeing soon realized that this would not provide a viable payload, so decided to widen the fuselage to 144 in (3,660 mm), the same as the KC-135 Stratotanker, which would allow six-abreast seating — and the shared use of the KC-135's tooling.[6] However, Douglas had launched its DC-8 with a fuselage width of 147 in (3,730 mm). The airlines liked the extra space, and so Boeing was obliged to increase the 707's cabin width again, this time to 148 in (3,760 mm). This meant that little of the tooling that was made for the Dash 80 was usable for the 707. The extra cost meant the 707 did not become profitable until some years after it would have if these modifications had not been necessary.


720 (707-020)
Cockpit crew
110 (2 class)

179 (1 class)
147 (2 class)

202 (1 class)
136 ft 2 in (41.25 m)
144 ft 6 in (44.07 m)
152 ft 11 in (46.61 m)
130 ft 10 in (39.90 m)
145 ft 9 in (44.42 m)
Tail height
41 ft 7 in (12.65 m)
42 ft 5 in (12.93 m)
Maximum Takeoff Weight (MTOW)
222,000 lb (100,800 kg)
257,000 lb (116,570 kg)
333,600 lb (151,320 kg)
Empty weight
103,145 lb (46,785 kg)
122,533 lb (55,580 kg)
146,400 lb (66,406 kg)
Takeoff run at MTOW
8,300 ft (2,515 m)
11,000 ft (3,330 m)
10,840 ft (3,280 m)
Fuel Capacity
16,060 US gal (60,900 l)
17,330 US gal (65,590 l)
23,820 US gal (90,160 l)
Landing run
5,750 ft (1,740 m)
6,200 ft (1,875 m)
5,950 ft (1,813 m)
Operating range (Max Payload)
3,680 nmi (6,820 km)
3,735 nmi (6,920 km)
Range at MTOW (max fuel)
3800 nmi (7,040 km)
4,700 nmi (8,704 km)
5,750 nmi (10,650 km)
Cruising speed
540 kn (1000 km/h)
525 kn (972 km/h)
Fuselage width
12 ft 4 in (3.76 m)
Powerplants (4 x)
Pratt & Whitney JT3C-7:

12,000 lbf (53.3 kN)
Pratt & Whitney JT3D-1:

17,000 lbf (75.6 kN)
PW JT3D-3:

18,000 lbf (80 kN)

PW JT3D-7:

19,000 lbf (84.4 kN)