The EWR VJ 10

The EWR VJ 101 was an experimental German jet fighter VTOL tiltjet aircraft. VJ stood for "Versuchsjäger", (German for "Experimental Fighter").  It was to be the basis for a successor to the F-104G Starfighter, but was cancelled in 1968 after a five-year test program. The VJ 101 was one of the first V/STOL designs to have the potential for eventual Mach 2 flight.

Heinkel and Messerschmitt had developed designs to meet the requirements of VTOL flight and by 1959, the two companies, along with Bölkow, had created a joint venture company called EWR, to build the VJ 101 C. The new proposal merged the characteristics of earlier Bölkow, Heinkel and Messerschmitt designs into a sleek, streamlined platform. The VJ 101 was similar in appearance to the Bell XF-109, both with rotating engines in nacelles at the wingtips. In addition to the wingtip engines, two further lift jets were installed in the fuselage to supplement the main engines in hovering flight.

In order to test the concept, EWR built a test rig called the Wippe (seesaw) in early 1960. The simple device incorporated a rudimentary cockpit on a horizontal beam with a "lift" engine mounted vertically at the centre for preliminary single-axis tests of the control system  A later "hover rig" was built that had the skeletal fuselage of the VJ 101C with three Rolls-Royce RB106 engines installed in the approximate positions they would occupy in the final flying version. The small engines each had 2,100 lbf (9.3 kN) thrust, enough to lift the test rig. After initial testing in May 1961 from a telescopic column, the new rig was able to "fly" in free flight in March 1962.  Additional tests with a cloth "skin" simulating fuselage and wings proved to be successful (showing satisfactory control in all seasons and weather conditions).

  Testing and evaluation

Two prototypes were built: X-1 and X-2. On 10 April 1963, the X-1 made its first hovering flight. The first transition from hovering flight to horizontal flight took place on 20 September 1963. The VJ 101C X-1 flew 40 aerodynamic flights, 24 hover flights and 14 full transitions. During these tests the sound barrier was broken, for the first time by a vertical take-off aircraft, but on 14 September 1964 a defect in the autopilot caused a crash. On July 29, 1964 the VJ 101 C flew at Mach 1.04 without use of an afterburner.

The second prototype X2 with a new autopilot made a successful transition on 22 October 1965. The tests were subsequently continued with X-2, which in contrast to X-1 had afterburners. However the project was cancelled in 1968. The proposed VJ 101 D Mach 2 interceptor was never built. VJ 101 C X 2 hangs today in the Deutsches Museum in Munich.

Although the VJ 101C did not proceed to production status, other projects including the Mirage IIIV, Hawker P.1154 (a supersonic parallel to what would become the Hawker Siddeley Harrier) and the much later F-35 Lightning II showed the promise of VTOL fighters.

General characteristics

• Crew: 1
• Length: 15.7 m (51 ft 6 in)
• Wingspan: 6.61 m (21 ft 8 in)
• Height: 4.1 (13 ft 6 in)
• Max takeoff weight: 6,100 kg (13,420 lb)
• Powerplant: 6× Rolls-Royce RB-145 turbojets, 12.2 kN (2,750 lbf) eac

Performance

• Maximum speed: Mach 1.04 achieved

Convair B-58 Hustler

The Convair B-58 Hustler was the first operational supersonic jet bomber, and the first capable of Mach 2 flight.  The aircraft was developed for the United States Air Force for service in the Strategic Air Command (SAC) during the late 1950s. Originally intended to fly at high altitudes and speeds to avoid Soviet fighters, the introduction of highly accurate Soviet surface-to-air missiles forced the B-58 into a low-level penetration role that severely limited its range and strategic value. This led to a brief operational career between 1960 and 1969. Its specialized role was succeeded by other American supersonic bombers, such as the FB-111A and the later B-1B Lancer.

The B-58 received a great deal of notoriety due to its sonic boom, which was often heard by the public as it passed overhead in supersonic flight.

The genesis of the B-58 program came in February 1949, when a Generalized Bomber Study (GEBO II) had been issued by the Air Research and Development Command (ARDC) at Wright-Patterson AFB, Ohio.[4] A number of contractors submitted bids including Boeing, Convair, Curtiss, Douglas, Martin and North American Aviation.

Building on Convair's experience of earlier delta-wing fighters, beginning with the XF-92A, a series of GEBO II designs were developed, initially studying swept and semi-delta configurations, but settling on the delta wing planform. The final Convair proposal, coded FZP-110, was a radical two-place, delta wing bomber design powered by General Electric J53 engines. The performance estimates included a 1,000 mph (1,609 km/h) speed and a 3,000 mi (4,828 km) range.

The USAF chose Boeing (MX-1712) and Convair to proceed to a Phase 1 study. The Convair MX-1626 evolved further into a more refined proposal redesignated the MX-1964. In December 1952, the Air Force selected the MX-1964 as the winner of the design competition ] to meet the newly proposed SAB-51 (Supersonic Aircraft Bomber) and SAR-51 (Supersonic Aircraft Reconnaissance), the first General Operational Requirement (GOR) worldwide for supersonic bombers. In February 1953, the Air Force issued a contract for development of Convair's design.

The resulting B-58 design was the first "true" USAF supersonic bomber program. The Convair design was based on a delta wing with a leading-edge sweep of 60° with four General Electric J79-GE-1 turbojet engines, capable of flying at twice the speed of sound. Although its large wing made for relatively low wing loading, it proved to be surprisingly well suited for low-altitude, high-speed flight. It seated three (pilot, bombardier/navigator, and defensive systems operator) in separated tandem cockpits. Later versions gave each crew member a novel ejection capsule that made it possible to eject at an altitude of 70,000 ft (21,000 m) at speeds up to Mach 2 (1,320 mph/2,450 km/h). Unlike standard ejection seats of the period, a protective clamshell would enclose the seat and the control stick with an attached oxygen bottle. In an unusual test program, live bears and chimpanzees were successfully used to test the ejection system.  The XB-70 would use a similar system.

Because of heat generated at Mach 2 cruise, not only the crew compartment, but the wheel wells and electronics bay were pressurized and air conditioned. The B-58 utilized one of the first extensive applications of aluminum honeycomb panels, which bonded outer and inner aluminum skins to a honeycomb of aluminum and fiberglass.

The pilot's cockpit was fairly conventional for a large multiengine aircraft.  The electronic controls were ambitious and advanced for the day. The navigator and DSO's cockpits featured wrap around dashboards with warning lights and buttons, and automatic voice messages and warnings from a tape system were audible through the helmet sets. Research during the era of all-male combat aircraft assignments revealed that a woman's voice was more likely to gain the attention of young men in distracting situations. Nortronics Division of Northrop Corporation selected actress and singer Joan Elms to record the automated voice warnings. To the men flying the B-58, the voice was known as "Sexy Sally."

The Sperry AN/ASQ-42 bombing/navigation system combined sophisticated inertial navigation with the KS-39 astro-tracker to provide heading reference, the AN/APN-113 Doppler radar to provide ground velocity and windspeed data, a search radar to provide range data for bomb release and trajectory, and a radio altimeter.  The AN/ASQ-42 was estimated to be 10 times more accurate than any previous bombing/navigation system.

Defensive armament consisted of a single 20 mm (0.79 in) T-171E-3 rotary cannon with 1,200 rounds of ammunition.  It was remotely controlled by the DSO through the Emerson MD-7 fire control radar system.  Offensive armament typically consisted of a single nuclear weapon, along with fuel tanks, in a streamlined MB-1C pod under the fuselage. Incurable difficulties with fuel leakage resulted in the replacement of the MB-1C with the TCP (Two Component Pod), which placed the nuclear weapon in an upper section while the lower fuel component could be independently jettisoned.

From 1961 to 1963, the B-58 was retrofitted with two tandem stub pylons under each wing, inboard of the engine pod, for B43 or B61 nuclear weapons for a total of five nuclear weapons per airplane. Although the USAF explored the possibility of using the B-58 for the conventional strike role, it was never equipped for carrying or dropping conventional bombs in service. A photo reconnaissance pod, the LA-331, was also fielded. Several other specialized pods for ECM or an early cruise missile were considered, but not adopted.

The first prototype, serial number 55-660, was completed in late August 1956.[13] The first flight took place in November 1956.[14] A difficult and protracted flight test program involving 30 aircraft continued until April 1959.[15] The final B-58 was delivered in October 1962.[15]

General characteristics

• Crew: 3: pilot; observer (navigator, radar operator, bombardier); defense system operator (DSO; electronic countermeasures operator and pilot assistant).
• Length: 96 ft 9 in (29.5 m)
• Wingspan: 56 ft 9 in (17.3 m)
• Height: 29 ft 11 in (8.9 m)
• Wing area: 1,542 ft² (143.3 m²)
• Airfoil: NACA 0003.46-64.069 root, NACA 0004.08-63 tip
• Empty weight: 55,560 lb (25,200 kg)
• Loaded weight: 67,871 lb (30,786 kg)
• Max takeoff weight: 176,890 lb (80,240 kg)
• Powerplant: 4× General Electric J79-GE-5A turbojet
• * Zero-lift drag coefficient: 0.0068
• Drag area: 10.49 ft² (0.97 m²)
• Aspect ratio: 2.09

Performance

• Maximum speed: Mach 2.0 [26] (1,319mph) at 40,000 ft (12,000 m)
• Cruise speed: 610 mph (530 kn, 985 km/h)
• Combat radius: 1,740 mi (1,510 nmi, 3,220 km)
• Ferry range: 4,720 mi (4,100 nmi, 7,590 km)
• Service ceiling: 63,400 ft (19,300 m)
• Rate of climb: 17,400 ft/min (5,310 m/min) at gross weight[27]
• Wing loading: 44.01 lb/ft² (214.9 kg/m²)
• Thrust/weight: 0.919
• Lift-to-drag ratio: 11.3 (without weapons/fuel pod)

Armament

• Guns: 1 × 20 mm (0.79 in) T171 cannon
• Bombs: 4 × B-43 or B61 nuclear bombs; maximum weapons load was 19,450 lb (8,823 kg)

Hawker

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)

Performance

• 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.

Specifications

	720 (707-020)	707-120B	707-320B
Cockpit crew	Three
Passengers	140	110 (2 class) 179 (1 class)	147 (2 class) 202 (1 class)
Length	136 ft 2 in (41.25 m)	144 ft 6 in (44.07 m)	152 ft 11 in (46.61 m)
Wingspan	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)

The Short SC.1

The Short SC.1 was the first British fixed-wing vertical take-off and landing (VTOL) aircraft. The SC.1 was designed to study the problems with VTOL flight and the transition to and from forward flight.

The SC.1 was designed to meet a Ministry of Supply (MoS) request for tender (ER.143T) for a vertical take-off research aircraft issued in September 1953. The design was accepted by the ministry and a contract was placed for two aircraft (XG900 and XG905) to meet Specification ER.143D dated 15 October 1954.

The SC.1 was a single-seat, low wing, tailless delta wing aircraft of approximately 8,000 lb all-up weight (max. 7,700 lb for vertical flight). It was powered by four vertically-mounted, lightweight Rolls-Royce RB108 lift engines providing a total vertical thrust of 8,600 lb and one RB.108 cruise engine in the rear to provide thrust for forward flight. The lift engines were mounted vertically in side-by-side pairs in a central bay so that their resultant thrust line passed close to the centre of gravity of the aircraft. These pairs of engines could be swivelled about transverse axes; they were therefore able to produce vectored thrust for acceleration/deceleration along the aircraft's longitudinal axis.

Bleeds from the four lift engines (using approximately 10% of the intake air mass/thrust) powered variable nose, tail and wing tip jets providing pitch, roll and yaw control at low speeds, when there was insufficient airflow over the control surfaces for conventional control. Fuel tanks were located along the wing leading edges and in "bag" tanks fitted between the main wing spars.

The SC.1 was also equipped with the first "fly-by-wire" control system for a VTOL aircraft. This permitted three modes of control of the aerodynamic surfaces and/or the nozzle controls:

1. Aerodynamic surfaces and air-jet nozzles controlled electrically via three independent servo-motors (with "three-way parallel" or "triplex" fail-safe operation) in conjunction with three autostabilizer control systems ("full fly-by-wire")
2. Hybrid-mode, in which the nozzles were controlled by servo/autostabilizer and the aerodynamic surfaces were linked directly to the manual controls
3. Direct mode, in which all controls were linked to the control stick

Modes 1 and 2 were selected on the ground; whenever the autostabilizer was in use, the pilot had an emergency override lever available with which to revert to direct control mode in flight. The outputs from the three control systems were compared and a "majority rule" enforced, ensuring that a failure in a single system was overridden by the other two (presumably correct) systems. Any failure in a "fly-by-wire" pathway was indicated to the pilot as a warning, which he could either choose to ignore or respond to by switching to direct (manual) control.

In common with other VTOL aircraft, the Short SC.1 suffered from vertical thrust loss due to the ground effect. Research into this on scale models suggested that for the SC.1 these losses would be between 15% and 20% at undercarriage height.. Fixed undercarriage legs were designed specifically for vertical flight with each leg carrying a pair of castoring wheels (the rear undercarriage was also fitted with disc brakes). Long-stroke oleos were used to cushion vertical landings.[The robust gear was able to withstand a descent rate of 18 ft (5.5m) per second.

Constructed at Short's Belfast factory in Northern Ireland, the SC.1 first undertook initial engine runs at this facility. After being transported by sea to Britain, the prototype (fitted only with the propulsion engine) was delivered to the Royal Aircraft Establishment at Boscombe Down. The first conventional takeoff and landing (CTOL) flight was made on 2 April 1957. Just over a year later the second prototype made the first tethered vertical flight was made on 26 May 1958, followed on 25 October of that year by the first free vertical flight. The first in-flight transition was made on 6 April 1960.

The SC.1 was shown at the Farnborough Airshow in 1960 and the Paris Air Show in 1961. Due to a malfunction of the controls, the second test aircraft crashed in Belfast on 2 October 1963, killing the pilot, J.R. Green. The aircraft itself was rebuilt for further testing.

The SC.1 flew for over ten years, providing a great deal of data that influenced later design concepts such as the "puffer jet" controls on the Hawker Siddeley P.1127, the precursor of the Hawker Siddeley Harrier. The work relating to vertical takeoff and landing techniques was also invaluable.

The first SC-1 (XG900) was used until 1971 for VTOL research and is now part of the Science Museum's aircraft collection at South Kensington, London. The second SC-1 (XG905) can be seen at the Flight Experience exhibit at the Ulster Folk and Transport Museum, Cultra, Northern Ireland

General characteristics

• Crew: 1
• Length: 25 ft 6 in (7.77 m)
• Wingspan: 23 ft 6 in (7.16 m)
• Height: ft in (m)
• Wing area: 211.5 ft² (19.65 m²)
• Empty weight: 6,260 lb (32,839 kg)
• Loaded weight (CTOL): 8,050 lb (3,650 kg)
• Loaded weight (VTOL): 7,700 lb (3,490 kg))
• Powerplant: ×
• * Powerplant:
• Lift: 4× Rolls-Royce RB108 turbojets, 2,130 lbf (9.47 kN) each
• Forward flight: 1× Rolls-Royce RB108 turbojets, 2,130 lbf each

Performance

• Maximum speed: 246 mph (214 knots, 396 km/h)
• Range: 150 mi (130 NM, 240 km)
• Service ceiling: ft (m)
• Wing loading: 38.1 lb/ft² (186.0 kg/m²)
• Thrust/weight (CTOL): 0.265
• Thrust/weight (VTOL): 1.11

The Ryan X-13A-RY Vertijet

The Ryan X-13A-RY Vertijet, Ryan Model 69, was an experimental Vertical Take-Off and Landing aircraft flown in the United States in the 1950s. The main objective of the project was to demonstrate the ability of a pure jet to vertically takeoff, hover, transition to horizontal forward flight, and vertically land.

Just after World War II, Ryan engineers wondered whether the Ryan/U.S. Navy FR-1 Fireball, which had a thrust-to-weight ratio of 1 at low fuel quantities, would take off vertically. The Navy's Bureau of Aeronautics in 1947 awarded Ryan a contract to investigate the development of a vertically launched jet fighter. This was part of a program to evaluate the feasibility of submarine-based aircraft. Ryan conducted remote controlled VTOL tethered rig tests from 1947 to 1950 and a flying rig in 1951. Ryan was awarded an Air Force contract in 1953 to develop an actual flying jet-powered VTOL aircraft, which was given the designation X-13. Two prototypes were built.

The Ryan X-13 Vertijet was 23 ft 5 in (7.14 m) long. It was just large enough to accommodate the single place cockpit (with a tilted seat) and the 10,000 lbf (45 kN) thrust Rolls-Royce Avon turbojet. The high mounted delta wing of the aircraft had a wingspan of only 21 ft (6.4 m) and was capped with flat endplates. The nose of the aircraft had a hook on the underside and a short pole for gauging distance from the trailer. The hook was used to hang the Vertijet from the vertical trailer bed landing platform. After the aircraft was secured vertically, the trailer was lowered to horizontal and then used to transport the aircraft on the ground. Pitch and yaw control in hover were provided by vectored engine thrust. Roll control was provided by "puffer" jets (also known as 'jet reaction control') mounted outboard of the wingtip endplates. The first prototype (#54-1619) was fitted with temporary landing gear and made its first horizontal flight on December 10, 1955. Later, it made full horizontal to vertical attitude conversions and back again at altitude. The first prototype then had the landing gear replaced with a tail mounted framework that held it in a vertical attitude on the ground. Using this rig, hooking practice was conducted. The second prototype (#54-1620), on April 11, 1957, made a vertical take-off from the vertically raised trailer, transitioned to horizontal flight and back again. It then returned to the vertical trailer and landed by hooking the landing wire. Flight tests were performed by Ryan's Chief Test Pilot Peter F. 'Pete' Girard.

On July 28-July 29, 1957, the X-13 was demonstrated in Washington, D.C. It crossed the Potomac River and landed at the Pentagon.

The Air Force chose not to continue development of the Ryan X-13 Vertijet because of the lack of an operational requirement.

The X-13 was designed to investigate vertical takeoff, horizontal flight transition, and return to vertical flight for landing. The first prototype of the X-13 was equipped with temporary tricycle landing gear. The X-13 was flown conventionally on December 10, 1955 to test its aerodynamic characteristics. The Vertijet was then fitted with a temporary "tail sitting" rig. On May 28, 1956, it was flown from the ground in a vertical position to test its hovering qualities. The X-13 VertiJet completed its first full-cycle flight at Edwards AFB, California on April 11, 1957, when it took off vertically from its mobile trailer, angled over into a horizontal attitude, and flew for several minutes. The X-13 then transitioned to vertical flight and slowly descended back onto its trailer and landed.

The two X-13 aircraft are now on display at aviation museums.

• The Vertijet which made the full-cycle flight on April 11, 1957 (#54-1620), was transferred to the National Museum of the United States Air Force, Dayton, Ohio in May 1959.[1] It is on display in the Museum's Research and Development Hanger.
• Prototype #54-1619 is on display at the San Diego Air & Space Museum.

Aircraft serial numbers

• X-13 #1 - USAF 54-1619
• X-13 #2 - USAF 54-1620

General characteristics

• Crew: one pilot
• Length: 23 ft 5 in (7.14 m)
• Wingspan: 21 ft 0 in (6.40 m)
• Height: 15 ft 2 in (4.62 m)
• Wing area: 191 ft² (17.8 m²)
• Empty weight: 5,334 lb (2,424 kg)
• Loaded weight: 6,730 lb (3,059 kg)
• Max takeoff weight: 7,200 lb (3,272 kg)
• Powerplant: 1× Rolls-Royce Avon turbojet, 10,000 lbf (44.6 kN)

Performance

• Maximum speed: 350 mph (560 km/h)
• Range: 192 miles (307 km)
• Service ceiling: 20,000 ft (6,100 m)
• Rate of climb: ft/min (m/min)
• Wing loading: 35.2 lb/ft² (172 kg/m²)
• Thrust/weight: 1.48

The Bell X-2 "Starbuster

The Bell X-2 "Starbuster was a research aircraft built to investigate flight characteristics in the Mach 2-3 range.

Providing adequate stability and control for aircraft flying at high supersonic speeds was only one of the major difficulties facing flight researchers as they approached Mach 3. For, at speeds in that region, they knew they would also begin to encounter a "thermal barrier", severe heating effects caused by aerodynamic friction. Constructed of stainless steel and a copper-nickel alloy, and powered by a two-chamber XLR25 2,500 to 15,000 lbf (11 to 67 kN) sea level thrust throttleable rocket engine, the swept-wing Bell X-2 was designed to probe this region.

Following launch from a modified B-50 bomber, Bell test pilot Jean "Skip" Ziegler completed the first unpowered glide flight of an X-2 at Edwards Air Force Base on 27 June 1952. Ziegler and aircraft #2 were subsequently lost on 12 May 1953, in an inflight explosion during a captive flight intended to check the aircraft's liquid oxygen system.[1][2]

Lt. Col. Frank K. "Pete" Everest (1920-2004) completed the first powered flight in the #1 airplane on 18 November 1955 and, by the time of his ninth and final flight in late July the following year, he had established a new speed record of Mach 2.87 (1,900 mph, 3050 km/h). The X-2 was living up to its promise, but not without difficulties. At high speeds, Everest reported that its flight controls were only marginally effective. High speed center of pressure shifts along with fin aeroelasticity were major factors. Moreover, simulation and wind tunnel studies, combined with data from his flights, suggested that the airplane would encounter very severe stability problems as it approached Mach 3.

A pair of young test pilots, Captains Iven C. Kincheloe and Milburn G. "Mel" Apt, were assigned the job of further expanding the envelope and, on 7 September 1956, Kincheloe became the first pilot ever to climb above 100,000 ft (30,500 m) as he flew the X-2 to a peak altitude of 126,200 ft (38,466 m). Just 20 days later, on the morning of 27 September, Mel Apt was launched from the B-50 for his first flight in a rocket airplane. He had been instructed to follow the "optimum maximum energy flight path" and to avoid any rapid control movements beyond Mach 2.7. Flying an extraordinarily precise profile, he became the first man to exceed Mach 3 that day, as he accelerated to a speed of Mach 3.2 (2,094 mph, 3,370 km/h) at 65,500 ft (19,960 m). The flight had been flawless to this point, but, for some reason, shortly after attaining top speed, Apt attempted a banking turn while the airplane was still well above Mach 3 (lagging instrumentation may have indicated that he was flying at a slower speed or perhaps he feared he was straying too far from the safety of his landing site on Rogers Dry Lake). The X-2 tumbled violently out of control and he found himself struggling with the same problem of "inertia coupling" which had overtaken Chuck Yeager in the X-1A nearly three years before. Yeager, although exposed to much higher vehicle inertial forces, as a result of extensive experience flying the X-1 was very familiar with its character, was able to recover. Unlike Yeager, Apt was unable to recover and both he and the aircraft were lost.

While the X-2 had delivered valuable research data on high-speed aerodynamic heat build-up and extreme high-altitude flight conditions, this tragic event terminated the program before the National Advisory Committee for Aeronautics could commence detailed flight research with the airplane, and the search for answers to many of the riddles of high-Mach flight had to be postponed until the arrival, three years later, of the most advanced of all the experimental rocket planes, the North American X-15.

Flight test program

Two aircraft completed a total of 20 flights (27 June 1952 - 27 September 1956).

• 46-674: seven glide flights, 10 powered flights, crashed 27 September 1956[2]
• 46-675: three glide flights, destroyed 12 May 1953

General characteristics

• Crew: one, pilot
• Length: 37 ft 10 in (11.5 m)
• Wingspan: 32 ft 3 in (9.8 m)
• Height: 11 ft 10 in (3.6 m)
• Wing area: 260 ft² (24.2 m²)
• Airfoil: 2S-50 bicon
• Empty weight: 12,375 lb (5,600 kg)
• Loaded weight: 24,910 lb (11,300 kg)
• Max takeoff weight: 24,910 lb (11,300 kg)
• Powerplant: 1× Curtiss-Wright XLR25 rocket engine, 15,000 lbf (67 kN)at sea level

Performance

• Maximum speed: Mach 3.196 (2,094 mph, 3,370 km/h)
• Service ceiling: 126,200 ft (38,466 m)

The Fairey Delta 2 or FD2

The Fairey Delta 2 or FD2 (internal designation Type V within Fairey) was a British supersonic research aircraft produced by the Fairey Aviation Company in response to a specification from the Ministry of Supply for investigation into flight and control at transonic and supersonic speeds. The design was a mid-wing tailless delta monoplane, with a circular cross-section fuselage and engine air-inlets blended into the wing roots. The engine was a Rolls-Royce Avon RA.14R with an afterburner. The Delta 2 had a very long tapering nose which obscured forward vision during landing, take-off and movement on the ground. To compensate, the nose section and cockpit drooped 10°, in a similar way to that used later on Concorde. Two aircraft were built: Serial numbers WG774 and WG777. The FD2 was used as the basis for Fairey's submissions to the Ministry for advanced all weather interceptor designs leading to the Fairey Delta 3 for the F.155 specification, but it never got past the drawing board stage. Testing The first FD2 was aircraft WG774 which made its maiden flight on 6 October 1954, flown by Fairey test pilot Peter Twiss. On 17 November 1954, WG774 suffered engine failure on its 14th flight when internal pressure build-up collapsed the fuselage collector tank at 30,000 ft (9,100 m), 30 mi (50 km) from Boscombe Down. Fairey pilot Peter Twiss, ex-Fleet Air Arm, managed to glide to a dead-stick landing at the airfield. Only the nose gear had deployed, and the aircraft sustained damage that sidelined it for eight months. Twiss, who was shaken up by the experience but otherwise uninjured, received the Queen's Commendation for Valuable Service in the Air. The FD2 test programmme did not resume until August 1955.  On 10 March 1956 the aircraft broke the World Air Speed Record, raising it to 1,132 mph (1,811 km/h), an increase of some 300 mph (480 km/h) over the record set in August 1955 by an North American F-100 Super Sabre. It thus became the first aircraft to exceed 1,000 mph (1,600 km/h) in level flight. This record stood until December 1957 when it was surpassed by a McDonnell JF-101A Voodoo of the USAF. BAC 221 The first Delta 2, WG774, was later rebuilt by British Aircraft Corporation (BAC), who had absorbed Fairey, in 1960 as the ogee-ogive wing form aircraft BAC 221. This was for aerodynamic research as part of the Concorde development programme. It featured a new wing, engine inlet configuration, a Rolls-Royce Avon RA.28, modified vertical stabiliser and a lengthened undercarriage to mimic Concorde's attitude on the ground. It flew from 1964 until 1973. Survivors WG774, in BAC 221 form, is now on display alongside the British Concorde prototype at the Fleet Air Arm Museum at Yeovilton. The second FD2, WG777, is preserved at the Royal Air Force Museum at RAF Cosford, alongside many other supersonic research aircraft. Fairey Delta 2 World speed record holder WG774 Role high-speed research aircraft National origin United Kingdom Manufacturer Fairey Aviation Company First flight 6 October 1954 Introduced Experimental Retired 1966 (WG777), 1973 (WG774) Status On Public Display Primary user Royal Aircraft Establishment Number built 2

The Tupolev Tu-104

The Tupolev Tu-104 (NATO reporting name: 'Camel') was a twin-engined medium-range turbojet-powered Soviet airliner and the world's first successful jet airliner. Although it was the fourth jet airliner to be launched (following, in order, the British de Havilland Comet, Canadian Avro Jetliner, and French Sud Caravelle), the Tu-104 was the second to enter regular service (with Aeroflot) and the first to provide a sustained and successful service (the Comet had been withdrawn following a series of crashes due to structural failure). The Tu-104 was the sole jetliner operating in the world between 1956 and 1958. [1]

In 1957, Czech Airlines ČSA became the first airline in the world to fly routes exclusively with jet airliners, using the TU-104A variant. In civil service, the Tu-104 carried over 90 million passengers with Aeroflot (then the world's largest airline), and a lesser number with ČSA, while it also saw operations with the Soviet Air Force. Its successors include the Tu-124 (the first turbofan-powered airliner), the Tu-134 and the Tu-154.

At the beginning of the 1950s, the Soviet Union's Aeroflot airline desperately needed a modern airliner with better capacity and performance than any other Soviet plane then in operation. The design request was filled by the Tupolev OKB, which based their new airliner on its Tu-16 'Badger' strategic bomber, the first version was more similar to the Tu-16 and it received square windows like the early De Havilland Comet, but this was later changed before the airplane made its maiden flight. The airplane was pressure tested in a watertank. The wings, engines, and tail surfaces of the Tu-16 were retained in the airliner, but the new design adopted a wider, pressurised fuselage to accommodate 50 passengers. The prototype (SSSR-L5400) first flew on June 17, 1955 with Yu.L. Alasheyev at the controls at Kharkiv plant in Ukraine. It was fitted with a drogue parachute which could shorten the landing run by up to 400 metres (1,300 ft). [1]

Its arrival in London during a 1956 state visit by Nikolai Bulganin and Nikita Khrushchev totally surprised Western observers who, at the time, thought the Soviets lacked the advanced technology required to build a commercial airliner with such performance. [1]

The Tu-104 was powered by two Mikulin AM-3 turbojets placed at the wing/fuselage junction (similar to the de Havilland Comet). The crew needed to fly her consisted of 5 people: 2 pilots, 1 navigator (placed in the glazed "bomber" nose), 1 flight engineer and 1 radio operator. This airplane raised great curiosity by its lavish "Victorian" interior - called so by some Western-hemisphere observers - due to the materials used: mahogany, copper and lace. [1]

On September 15, 1956, it began revenue service in Aeroflot's Moscow-Omsk-Irkutsk route, replacing the old Ilyushin Il-14. The flight time was reduced from 13 hours and 50 minutes to 7 hours and 40 minutes. [1]

In 1957, CSA became the first non-Russian airline to operate the Tu-104 in the routes with Moscow, Paris and Brussels as destinations. [1] CSA Czechoslovak Airlines, the Czechoslovak national airline, bought six (four new and two used) of Tu-104As configured for 81 passengers. [1]

The small capacity (50 passengers) and the excessive strength and therefore weight inherited from the Tupolev Tu-16 were some of the reasons for its low profitability. [1]

By the time production ceased in 1960, about 200 had been built. Aeroflot did not retire the Tu-104 from civil service until 1979, and the aircraft continued to serve in the Soviet Air Force until 1981, when a crash showed it to be unsafe. The last flight of the type was a ferry flight to a museum in 1986.

Following its removal from civil service, several aircraft were transferred to the Soviet military, which used them as staff transports and to train cosmonauts in zero gravity.

Tu-104
Aeroflot Tupolev Tu-104B at Arlanda Airport
Role	Airliner
Manufacturer	Tupolev OKB
First flight	17 June 1955
Introduced	15 September 1956 with Aeroflot
Retired	1986
Primary users	Aeroflot ČSA
Produced	1956-1960
Number built	200
Developed from	Tupolev Tu-16

General characteristics

• Crew: 7
• Capacity: 50-100 passengers
• Length: 40.05 m (131 ft 5 in)
• Wingspan: 34.54 m (113 ft 4 in)
• Height: 11.90 m (39 ft 0 in)
• Wing area: 184 m² (1,975 ft²)
• Empty weight: 41,600 kg (91,710 lb)
• Max takeoff weight: 76,000 kg (167,550 lb)
• Powerplant: 2× Mikulin AM-3M-500 turbojets, 95.1 kN (21,400 lbf) each

Performance

• Maximum speed: 950 km/h (512 knots, 590 mph (950 km/h))
• Range: 2,650 km (1,430 nm, 1,650 mi)
• Service ceiling: 11,500 m (37,730 ft)
• Rate of climb: 10 m/s (2,000 ft/min)

The Bell X-1

The Bell X-1, originally designated XS-1, was a joint NACA-U.S. Army Air Forces/US Air Force supersonic research project and the first aircraft to exceed the speed of sound in controlled, level flight. This resulted in the first of the so-called X-planes, an American series of experimental aircraft designated for testing of new technologies and usually kept highly secret.

On 16 March 1945, the United States Army Air Forces' Flight Test Division and the National Advisory Committee for Aeronautics (NACA) (now NASA) contracted Bell Aircraft to build three XS-1 (for "Experimental, Supersonic", later X-1) aircraft to obtain flight data on conditions in the transonic speed range.  The XS-1 was the first high-speed aircraft built purely for aviation research purposes and was never intended for production.[citation needed]

The X-1 was in principle a "bullet with wings" that closely resembled the shape of the Browning .50-caliber (12.7 mm) machine gun bullet that was known to be stable in supersonic flight  The pattern shape was followed to the point of seating the pilot behind a sloped, framed window inside a confined cockpit in the nose. After the aircraft ran into compressibility problems in 1947, it was modified to feature a variable-incidence tailplane. An all-moving tail was developed by the British for the Miles M.52, and first saw actual transonic flight on the Bell X-1; ] that allowed it to pass through the sound barrier safely.

The rocket propulsion system was a four-chamber engine built by Reaction Motors, Inc., one of the first companies to build liquid-propellant rocket engines in America. It burned ethyl alcohol diluted with water and liquid oxygen. The thrust could be changed in 1500 lbf increments by firing one or more of the chambers. The fuel and oxygen tanks for the first two X-1 engines were pressurized with nitrogen and the rest with steam-driven turbopumps. The all-important fuel turbopumps, necessary to raise the chamber pressure and thrust, while lightening the engine, were built by Robert Goddard who was under Navy contract to provide jet-assisted takeoff rockets.

Bell Aircraft Chief Test Pilot, Jack Woolams became the first to fly the XS-1, in a glide flight over Pinecastle Army Airfield, in Florida, on 25 January 1946. Woolams would complete nine additional glide flights over Pinecastle before March 1946, when the #1 aircraft was returned to Bell for modifications in anticipation of the powered flight tests, planned for Muroc Army Air Field (now Edwards Air Force Base) in California. Following Woolams' death on 30 August 1946, Chalmers "Slick" Goodlin was the primary Bell Aircraft test pilot of X-1-1 (serial 46-062). He made 26 successful flights in both of the X-1 aircraft from September 1946 until June 1947.

The Army Air Force was unhappy with the cautious pace of flight envelope expansion and Bell Aircraft's flight test contract for aircraft #46-062 was terminated and was taken over by the Army Air Force Flight Test Division on 24 June after months of negotiation. Goodlin had demanded a US$150,000 bonus for breaking the sound barrier.  Flight tests of the X-1-2 (serial 46-063) would be conducted by NACA to provide design data for later production high-performance aircraft.

On 14 October 1947, just under a month after the United States Air Force had been created as a separate service, the tests culminated in the first manned supersonic flight, piloted by Air Force Captain Charles "Chuck" Yeager in aircraft #46-062, which he had christened ‘Glamorous Glennis’, after his wife. The rocket-powered aircraft was launched from the bomb bay of a specially modified B-29 and glided to a landing on a runway. XS-1 flight number 50 is the first one where the X-1 recorded supersonic flight, at Mach 1.06 (361 m/s, 1,299 km/h, 807.2 mph) peak speed; however, Yeager and many other personnel believe Flight #49 (also with Yeager piloting), which reached a top recorded speed of Mach 0.997 (339 m/s, 1,221 km/h), may have, in fact, exceeded Mach 1.[citation needed] (The measurements were not accurate to three significant figures and no sonic boom was recorded for that flight.)

As a result of the X-1's initial supersonic flight, the National Aeronautics Association voted its 1948 Collier Trophy to be shared by the three main participants in the program. Honored at the White House by President Harry S. Truman were Larry Bell for Bell Aircraft, Captain Yeager for piloting the flights, and John Stack for the NACA contributions.

The research techniques used in the X-1 program became the pattern for all subsequent X-craft projects. The NACA X-1 procedures and personnel also helped lay the foundation of America's space program in the 1960s. The X-1 project defined and solidified the post-war cooperative union between U.S. military needs, industrial capabilities, and research facilities. The flight data collected by the NACA in the X-1 tests then provided a basis for American aviation supremacy in the latter half of the 20th century.

Aircraft #46-062 is currently on display in the Milestones of Flight gallery of the National Air and Space Museum in Washington, DC, alongside the Spirit of St. Louis and SpaceShipOne. Aircraft #46-063, now the X-1E, is on display in front of the NASA Dryden Flight Research Center headquarters building.

X-1A

Ordered by the Air Force on 2 April 1948, the X-1A (serial 48-1384) was intended to investigate aerodynamic phenomena at speeds above Mach 2 (681 m/s, 2,451 km/h) and altitudes greater than 90,000 ft (27 km), specifically focusing on dynamic stability and air loads. Longer and heavier than the original X-1, with a bubble canopy for better vision, the X-1A was powered by the same Reaction Motors XLR-11 rocket engine. The aircraft first flew, unpowered, on 14 February 1953 at Edwards AFB, with the first powered flight on 21 February. Both flights were piloted by Bell test pilot Jean Ziegler.

After NACA started its high-speed testing with the Douglas Skyrocket, culminating in Scott Crossfield achieving Mach 2.005 on 20 November 1953, the Air Force started a series of tests with the X-1A, which the test pilot of the series, Chuck Yeager, named "Operation NACA Weep". These culminated on 12 December 1953, when Yeager achieved an altitude of 74,700 feet (22,770 m) and a new air speed record of Mach 2.44 (equal to 1620 mph, 724.5 m/s, 2608 km/h at that altitude). Unlike Crossfield in the Skyrocket, Yeager achieved that in level flight. Shortly after, the aircraft spun out of control, due to the then not yet understood phenomenon of inertia coupling. The X-1 dropped from maximum altitude to 25,000 feet (7,620 m), exposing the pilot to accelerations of up to 8g, during which Yeager broke the canopy with his helmet before regaining control.

The aircraft was transferred to NACA in September 1954. Following modifications, including the installation of an ejection seat, the aircraft was lost on 8 August 1955 while being prepared for launch from the RB-50 mothership, becoming the first of many early X-planes that would be lost to explosions.

Douglas Skyrocket (D-558-2 or D-558-II

The Douglas Skyrocket (D-558-2 or D-558-II) was a rocket and jet-powered supersonic research aircraft built by the Douglas Aircraft Company for the United States Navy. On 20 November 1953, shortly before the 50th anniversary of powered flight, Scott Crossfield piloted the Douglas D-558-2 Skyrocket to Mach 2, or more than 1,290 mph (2076 km/h), the first time an aircraft had exceeded twice the speed of sound.

The "-2" in the aircraft's designation referred to the fact that the Skyrocket was the phase-two version of what had originally been conceived as a three-phase program. The phase-one aircraft, the D-558-1, was jet powered and had straight wings. The third phase, which never came to fruition, would have involved constructing a mock-up of a combat type aircraft embodying the results from the testing of the phase one and two aircraft. The eventual D-558-3 design, which was never built, was for a hypersonic aircraft similar to the North American X-15.[1].

When it became obvious that the D558-1 fuselage could not be modified to accommodate both rocket and jet power, the D558-2 was conceived as an entirely different aircraft[2]. A contract change order was issued on 27 January 1947 to formally drop the final three D558-1 aircraft and substitute three new D558-2 aircraft instead[3].

The Skyrocket featured wings with a 35-degree sweep and horizontal stabilizers with 40-degree sweep. The wings and empennage were fabricated from aluminum and the large fuselage was of primarily magnesium construction. The Skyrocket was powered by a Westinghouse J34-40 turbojet engine fed through side intakes in the forward fuselage. This engine was intended for takeoff, climb and landing. For high speed flight, a four-chamber Reaction Motors LR8-RM-6 engine (the Navy designation for the Air Force's XLR-11 used in the Bell X-1), was fitted. This engine was rated at 6,000 lbf (27 kN) static thrust at sea level. A total of 250 gallons (946 liters) of aviation fuel, 195 gallons of alcohol, and 180 gallons of liquid oxygen were carried in fuselage tanks.

The Skyrocket was configured with a flush cockpit canopy, but visibility from the cockpit was poor, so it was re-configured with a raised cockpit with conventional angled windows. This resulted in a greater profile area at the front of the aircraft, which was balanced by an additional 14 inches (36 cm) of height added to the vertical stabilizer. Like its predecessor, the D558-1, the D558-2 was designed so that the forward fuselage, including cockpit, could be separated from the rest of the aircraft in an emergency. Once the forward fuselage had decelerated sufficiently, the pilot would then be able to escape from the cockpit by parachute.

General characteristics

• Crew: one pilot
• Length: 42 ft 0 in (12.8 m)
• Wingspan: 25 ft 0 in (7.6 m)
• Height: 22 ft 8 in (3.8 m)
• Wing area: 175 ft² (16.2 m²)
• Empty weight: 9,421 lb (4,273 kg)
• Max takeoff weight: 15,266 lb (6,923 kg)
• Powerplant:
• 1× Westinghouse J34-WE-40 turbojet, 3,000 lbf (13 kN)
• 1× Reaction Motors XLR-8-RM-5 rocket engine, 6,000 lbf (27 kN)

Performance

• Maximum speed: 720 mph, 1,250 mph when air-launched (1,160 km/h, 2,010 km/h when air-launched)
• Stall speed: 160.1 mph (257.7 km/h)
• Service ceiling: 16,500 ft (5,030 m)
• Rate of climb: 22,400 ft/min, 11,100 ft/min under rocket power only (6,830 m/min., 3,380 m/min under rocket power only)
• Wing loading: 87.2 lb/ft² (426 kg/m²)
• Thrust/weight (jet): 0.39

The Whitcomb area rule

The Whitcomb area rule, also called the transonic area rule, is a design technique used to reduce an aircraft's drag at transonic and supersonic speeds, particularly between Mach 0.8 and 1.2. This is the operating speed range of the majority of commercial and military fixed-wing aircraft today.

At high-subsonic flight speeds, supersonic airflow can develop in areas where the flow accelerates around the aircraft body and wings. The speed at which this occurs varies from aircraft to aircraft, and is known as the critical Mach number. The resulting shock waves formed at these points of supersonic flow can bleed away a considerable amount of power, which is experienced by the aircraft as a sudden and very powerful form of drag, called wave drag. To reduce the number and power of these shock waves, an aerodynamic shape should change in cross sectional area as smoothly as possible. This leads to a "perfect" aerodynamic shape known as the Sears-Haack body, roughly shaped like a cigar but pointed at both ends.

The area rule says that an airplane designed with the same cross-sectional area as the Sears-Haack body generates the same wave drag as this body, largely independent of the actual shape. As a result, aircraft have to be carefully arranged so that large volumes like wings are positioned at the widest area of the equivalent Sears-Haack body, and that the cockpit, tailplane, intakes and other "bumps" are spread out along the fuselage and or that the rest of the fuselage along these "bumps" is correspondingly thinned.

The area rule also holds true at speeds higher than the speed of sound, but in this case the body arrangement is in respect to the Mach line for the design speed. For instance, at Mach 1.3 the angle of the Mach cone formed off the body of the aircraft will be at about μ = arcsin (1/M) = 50,3 deg (μ is the sweep angle of the Mach cone). In this case the "perfect shape" is biased rearward, which is why aircraft designed for high speed cruise tend to be arranged with the wings at the rear. A classic example of such a design is Concorde.

The area rule was discovered by Otto Frenzl when comparing a swept wing with a w-wing with extreme high wave drag   working on a transonic wind tunnel at Junkers works in Germany between 1943 and 1945. He wrote a description on 17 December 1943, with the title “Arrangement of Displacement Bodies in High-Speed Flight”; this was used in a patent filed in 1944. The results of this research were presented to a wide circle in March 1944 by Theodor Zobel at the “Deutsche Akademie der Luftfahrtforschung” (German Academy of aeronautics research) in the lecture “Fundamentally new ways to increase performance of high speed aircraft.”  The design concept was applied to German wartime aircraft, including a rather odd Messerschmitt project, but their complex double-boom design was never built even to the extent of a model. Several other researchers came close to developing a similar theory, notably Dietrich Küchemann who designed a tapered fighter that was dubbed the “Küchemann Coke Bottle” when it was discovered by U.S. forces in 1946. In this case Küchemann arrived at the solution by studying airflow, notably spanwise flow, over a swept wing. The swept wing is already an application of the area rule.

Wallace D. Hayes, a pioneer of supersonic flight, developed the supersonic area rule in publications beginning in 1947 with his Ph.D. thesis at the California Institute of Technology.

Richard T. Whitcomb, after whom the rule is named, independently discovered this rule in 1952, while working at the NACA. While using the new Eight-Foot High-Speed Tunnel, a wind tunnel with performance up to Mach 0.95 at NACA's Langley Research Center, he was surprised by the increase in drag due to shock wave formation. The shocks could be seen using Schlieren photography, but the reason they were being created at speeds far below the speed of sound, sometimes as low as Mach 0.70, remained a mystery.

In late 1951, the lab hosted a talk by Adolf Busemann, a famous German aerodynamicist who had moved to Langley after World War II. He talked about the difference in the behavior of airflow at speeds approaching the supersonic, where it no longer behaved as an incompressible fluid. Whereas engineers were used to thinking of air flowing smoothly around the body of the aircraft, at high speeds it simply did not have time to "get out of the way", and instead started to flow as if it were rigid pipes of flow, a concept Busemann referred to as "streampipes", as opposed to streamlines, and jokingly suggested that engineers had to consider themselves "pipefitters".

Several days later Whitcomb had a "Eureka" moment. The reason for the high drag was that the "pipes" of air were interfering with each other in three dimensions. One could not simply consider the air flowing over a 2D cross-section of the aircraft as others could in the past; now they also had to consider the air to the "sides" of the aircraft which would also interact with these streampipes. Whitcomb realized that the Sears-Haack shaping had to apply to the aircraft as a whole, rather than just to the fuselage. That meant that the extra cross-sectional area of the wings and tail had to be accounted for in the overall shaping, and that the fuselage should actually be narrowed where they meet to more closely match the ideal.

The area rule was immediately applied to a number of development efforts. One of the most famous was Whitcomb's personal work on the re-design of the Convair F-102 Delta Dagger, a U.S. Air Force jet fighter that was demonstrating performance considerably worse than expected. By indenting the fuselage beside the wings, and (paradoxically) adding more volume to the rear of the plane, transonic drag was considerably reduced and the original Mach 1.2 design speeds were reached. The culminating design of this research was the Convair F-106 Delta Dart, an aircraft which for many years was the USAF's primary all-weather interceptor.

Numerous designs of the era were likewise modified in this fashion, either by adding new fuel tanks or tail extensions to smooth out the profile. The Tupolev Tu-95 'Bear', a Soviet-era bomber, was modified by adding large bulged nacelles behind the two inner engines, instead of decreasing the cross section of the fuselage next to the wing root. It remains the highest speed propeller aircraft in the world. The Convair 990 used a similar solution, adding bumps called antishock bodies to the trailing edge of the upper wing. The 990 remains the fastest U.S. airliner in history, cruising at up to Mach 0.89. Designers at Armstrong-Whitworth took the concept a step further in their proposed M-Wing, in which the wing was first swept forward and then to the rear. This allowed the fuselage to be narrowed on either side of the root instead of just behind it, leading to a smoother fuselage that remained wider on average than one using a classic swept wing.

One interesting outcome of the area rule is the shaping of the Boeing 747's upper deck. The aircraft was designed to carry standard cargo containers in a two-wide, two-high stack on the main deck, which was considered a serious accident risk for the pilots if they were located in a cockpit at the front of the aircraft. They were instead moved above the deck in a small "hump", which was designed to be as small as possible given normal streamlining principles. It was later realized that the drag could be reduced much more by lengthening the hump, using it to reduce wave drag offsetting the tail surface's contribution. The new design was introduced on the 747-300, improving its cruise speed and lowering drag.

Aircraft designed according to Whitcomb's area rule looked odd at the time they were first tested, (eg. the Blackburn Buccaneer), and were dubbed "flying Coke bottles," but the area rule is effective and came to be an expected part of the appearance of any transonic aircraft. Later designs started with the area rule in mind, and came to look much more pleasing. Although the rule still applies, the visible fuselage "waisting" can only be seen on the B-1B Lancer, Learjet 60, and the Tupolev Tu-160 'Blackjack' — the same effect is now achieved by careful positioning of aircraft components, like the boosters and cargo bay on rockets; the jet engines in front of (and not directly below) the wings of the Airbus A380; the jet engines behind (and not purely at the side of) the fuselage of a Cessna Citation X; the shape and location of the canopy on the F-22 Raptor; and the image of the Airbus A380 above showing obvious area rule shaping at the wing root, which is practically invisible from any other angle. Aftershock bodies are likewise mostly "invisible" today, often serving double-duty as flap actuators, which are also visible on the A380.

The Rolls-Royce Thrust Measuring Rig

The Rolls-Royce Thrust Measuring Rig (TMR) was a pioneering vertical take-off and landing aircraft developed by Rolls-Royce in the 1950s. The TMR used two Nene turbojet engines mounted back-to-back horizontally within a steel framework, raised upon four legs with castors for wheels. The TMR had no lifting surfaces (wings, blades, etc.) and was understandably nicknamed the Flying Bedstead.

The output of the jets was directed towards the centre of the rig with one jetpipe discharging downwards through a central nozzle while the other jet discharged downwards through two smaller nozzles on either side. Four outrigger arms extended out from the rig, one on either side and one each at the front and rear, through which compressed air was released for control in roll, pitch and yaw when in flight. The purpose of the rig was, as the name suggests, to test turbojet engines for lifting purposes and to develop techniques for controlling such an aircraft.

The man largely responsible for the development of the TMR was Dr Alan Arnold Griffith who had worked on gas turbine design at the Royal Aircraft Establishment in the 1920s and was a pioneer of jet lift technology. Griffith was employed by Rolls-Royce in 1939.

Two Thrust Measuring Rigs were built with the first taking to the air on 3 July 1953 at Hucknall Aerodrome, Nottinghamshire, England, though it remained tethered to the ground while airborne. The first free flight by the TMR was made on 3 August 1954 with R.T. Shepherd, Rolls-Royce's chief test pilot, at the controls. The TMR had only marginal excess power and flying was tricky due to this, combined with the slow throttle response of the engines, and a considerably degree of anticipation in the use of engine power was required in order to prevent overshooting of desired altitude, and to ensure a gentle touchdown when landing. As the TMR possessed no inherent stability, it incorporated an automatic stabiliser system.

Following successful trials of the TMR, Rolls-Royce began development of the Rolls-Royce RB.108 direct-lift turbojet, five of which were used to power the first true British VTOL aircraft, the Short SC.1.

The second Thrust Measuring Rig (Serial XK426) was destroyed in 1957 but the first (Serial XJ314) is preserved and on public display at the Science Museum in London, England.

Bristol Britannia

Bristol Britannia

Type 175 Britannia
Royal Air Force Bristol Britannia Spica in 1964.
Role	Airliner
Manufacturer	Bristol Aeroplane Company
First flight	16 August 1952
Introduced	1957
Retired	1975
Primary users	British Overseas Airways Corporation Royal Air Force
Number built	85
Variants	Canadair Argus Canadair CL-44

The Bristol Type 175 Britannia was a British medium/long-range airliner built by the Bristol Aeroplane Company in 1952 to fly across the British Empire. Soon after production the turboprop engines proved susceptible to inlet icing and two prototypes were lost while solutions were found. By the time it was cleared, jets from France, UK and the US were about to enter service and only 85 Britannias were built before production ended in 1960. Nevertheless, the Britannia is considered the high point in turboprop design and was popular with passengers, earning itself the title of "The Whispering Giant" for its quiet and smooth flying.

 

In 1942, during the Second world War, the US and UK agreed to split aircraft construction; the US concentrating on transport aircraft, and the UK on heavy bombers. This left the UK with little experience in transport construction at the end of the war, so in 1943, a committee under Lord Brabazon of Tara, investigated the future of the British civilian airliner market. The Brabazon Committee called for four main types of aircraft.

Bristol won the Type I and Type III contracts, delivering their Type I design, the Bristol Brabazon in 1949. The initial requirement for the Type III, Specification C.2/47, was issued by the Minister of Supply for an aircraft capable of carrying 48 passengers and powered with Bristol Centaurus radial engines. Turboprop and compound engines were also considered, but they were so new that Bristol could not guarantee the performance specifications. After wrangling between the Ministry of Supply and British Overseas Airways Corporation (BOAC) over costs, the go-ahead was given in July 1948 for three prototypes, although the second and third were to be convertible to Bristol Proteus turboprops.

In October, with work already underway, BOAC decided that only a Proteus-engined aircraft was worth working on, and the project was redrawn to allow both turboprop and piston aircraft. BOAC purchased options for 25 aircraft on 28 July 1949, to be powered initially with the Centaurus engine but to be re-fitted with the Proteus when available. The design was now aimed at long-haul Empire and trans-Atlantic routes rather than the medium haul Empire routes originaly planned and had grown to accomodate 83 passengers.

By the time the first prototype, registered G-ALBO, first flew on 16 August 1952 at Filton, BOAC and Bristol had dropped the Centaurus because the turboprop Proteus had shown such promise. The Britannia was now a 90-seater and BOAC ordered 15 of these Series 100s. In 1953 and 54, three de Havilland Comets disappeared without explanation, and the Air Ministry demanded the Britannia undergo lengthy tests. Further, delays were caused by engine problems, mostly related to icing and the loss of the second prototype G-ALRX in an accident caused by a failed engine in December 1953. This delayed the in-service date until February 1957, when BOAC put their first Britannia 102s into service on the London to South Africa route, with Australia following a month later.

Bristol then upgraded the design as a larger transatlantic airliner for BOAC, resulting in the Series 200 and 300. The new version had a fuselage stretch of 10 ft 3 in (3.12 m) and upgraded Proteus engines, and was offered as the all-cargo Series 200, the cargo/passenger (combi) Series 250, and the all-passenger Series 300.

The first public service was operated on the 1 February 1957 with a BOAC flight between London and Johannesburg. By August 1957 the first 15 Series 102 aircraft had been delivered to BOAC.  The last ten aircraft of the order were built as Series 300 aircraft for transatlantic operations.

The first 301 flew on 31 July 1956. BOAC ordered seven Model 302s but never took delivery - instead they were taken on by airlines including Aeronaves de México and Ghana Airways. The main long-range series were the 310s, of which BOAC took 18 and, after deliveries began in September 1957, put them into service between London and New York. The 310 series (318) also saw transatlantic service with Cubana de Aviación starting in 1958. In total 45 Series 300s were built, the first jet-powered, albeit in turboprop form, airliner to enter regular non-stop transatlantic service in both directions.

A further 23 Model 252 and 253 aircraft were purchased by the RAF, as the Britannia C.2 and C.1 respectively. Those in RAF service were allocated the names of stars, "Arcturus", "Sirius", "Vega" etc. The last retired in 1975, and were used by civil operators in Africa, Europe and the Middle East into the late 1990s.

Most aircraft were built by Bristol at Filton Aerodrome but 15 were built at Belfast by Short Brothers and Harland.

A licence was also issued to Canadair to build a maritime reconnaissance aircraft , the Canadair Argus and long-range transport, the Canadair Yukon. Unlike the Britannia, the Argus was built for endurance, not speed, and used four Wright R-3350-32W Turbo-Compound engines which use less fuel at low altitude. The unpressurized interior was left with almost no room to move, packed with sensors and weapons. Canadair also built 37 turboprop Rolls Royce Tyne-powered CL-44 variants for the civil market similar those built for the RCAF in CC-106 Yukon guise, most of which were used as freighters. Four were built as CL-44-Js had their fuselages lengthened, making them the highest capacity passenger aircraft of the day, for service with the Icelandic budget airline Loftleiðir. One, a modified Guppy version, remains airworthy, but not flying. Several were built with swing-tails to allow straight-in cargo loading.

General characteristics

• Crew: 4-7
• Capacity: 139 passengers (coach class)
• Length: 124 ft 3 in (37.88 m)
• Wingspan: 142 ft 3 in (43.36 m)
• Height: 37 ft 6 in (11.43 m)
• Wing area: 2,075 ft² (192.8 m²)
• Empty weight: 86,400 lb   (38,500 kg)
• Max takeoff weight: 185,000 lb (84,000 kg)
• Powerplant: 4× Bristol Proteus 765 turboprops, 4,450 ehp (3,320 kW) each

Performance

• Maximum speed: 397 mph (345 knots, 639 km/h)
• Cruise speed: 357 mph (310 kn, 575 km/h) at 22,000 ft (6,700 m)
• Range: 4,430 mi (3,852 nmi, 7,129 km)
• Service ceiling: 24,000 ft ] (7,300 m)