Saturday, 26 December 2009

HEINKEL HE-280, FINE UNPRODUCTED NAZI'S JETS



The Heinkel He 280 was the first turbojet-powered fighter aircraft in the world. It was inspired by Ernst Heinkel's emphasis on research into high-speed flight and built on the company's experience with the He 178 jet prototype. A combination of technical and political factors led to it being passed over in favor of the Messerschmitt Me 262.[citation needed] Only nine were built and none reached operational status

Development

The Heinkel company began the He 280 project on its own initiative after the He 178 had been met with indifference from the Reichsluftfahrtministerium ("RLM") (Ger. "Reich Aviation Ministry"). The head designer was Robert Lusser, who began the project under the designation He 180 in late 1939. It had a typical Heinkel fighter fuselage, elliptically-shaped wings and a dihedralled tailplane with twin fins and rudders. The landing gear was of the retractable tricycle type with very little ground clearance.[2] Internally, the He 280 was equipped with a compressed-air powered ejection seat, the first aircraft to carry one. It was also planned to pressurize the cockpit.[citation needed]

The first prototype was completed in the summer of 1940, but the HeS 8 intended to power it was running into difficulties. On 22 September 1940, while work on the engine continued, the first prototype started glide tests with ballast hung in place of its engines.[2] It would be another six months before Fritz Schäfer would take the second prototype into the air under its own power, on 30 March 1941. The type was then demonstrated to Ernst Udet, head of RLM's development wing, on 5 April, but like its predecessor, it apparently failed to make an impression.[citation needed]

Had Udet approved development, Heinkel would have received the extra funding which they needed. This might have led to a rectification of the problems they were having with the jet engines. This was the case across all jet engine development in Germany; government funding was lacking at the critical stage that of initial development. The entire jet program was under-funded, with the effect unreliable engines were commonplace.[citation needed]

A contest flight in 1941 comparing an He 280 with a Focke-Wulf Fw 190 had the He 280 completing four laps of an oval course before the Fw 190 could complete three. Ernst Heinkel designed a smaller jet fighter airframe for the He 280 that was well matched to the lower-thrust jet engines available in 1941. The maximum weight of the He 280 was 4,296 kg (9,470 lb), compared to 7,130 kg (15,720 lb) for the Me 262 (which did not get an adequate thrust engine until late 1944). The He 280 could have gone into production by late 1941 and maintained the air superiority which the Fw 190 had established, and filled the gap between the Fw 190 and Me 262. Initial problems with the HeS 8 engine would have likely been ironed out as production of the fighter began.

Some of the resistance to the He 280 would make little sense today. The tricycle landing gear was considered too frail for grass or dirt airfields which were common at the time especially in Russia and North Africa. The Me 262 was originally designed as a tail-dragger, but this configuration makes it difficult for a jet to become airborne. Test pilots had to tap on the brakes to get the Me 262 tail off the ground while trying to take off. Pioneered on its fifth prototype with fixed gear, and made retractable on the sixth prototype and afterwards, the Me 262 emerged with its redesigned tricycle landing gear.

One benefit of the He 280 which impressed the political leadership was the fact that the jet engines could burn kerosene, which requires much less expense and refining than the high-octane fuel used by piston-engine aircraft. The He 280 might have been more easily "sold" if Heinkel stressed the possibility of using it as an attack aircraft for anti-shipping. While the R4M rockets were not available until 1944, the Germans did develop the Nebelwerfer in 1941, which was a 150 mm (5.9 in) artillery rocket launcher. These tubes could have been mounted underneath the wings of a jet. German pilots complained that bombs dropped by the Me 262 had little chance of hitting their targets. A forward-firing recoilless weapon would have been much more effective.

Had the German government given support to production, the He 280s could conceivably have gone into production earlier in the war and reached the Luftwaffe earlier than was ultimately the case with the Me 262. But it was not to be, as Udet, on that April day in 1941, could not see a need for a plane without propellers, no matter what its future might be.[citation needed]

Over the next year, progress was slow due to the ongoing engine problems. A second engine design, the HeS 30 was also undergoing development, both as an interesting engine in its own right, as well as a potential replacement for the HeS 8. In the meantime, alternative powerplants were considered, including the Argus As 014 pulsejet that famously powered the V-1 flying bomb.[3] (Using as many as eight was proposed.)[4]

By the end of 1943, however, the third prototype was fitted with refined versions of the HeS 8 engine and was ready for its next demonstration. On 22 December, a mock dogfight was staged for RLM officials in which the He 280 was matched against an Fw 190. Here, the jet demonstrated its vastly superior speed.[citation needed] Finally, at this point the RLM became interested and placed an order for 20 pre-production test aircraft, to be followed by 300 production machines.

Engine problems continued to plague the project. In 1942, the RLM had ordered Heinkel to abandon the HeS 8 and HeS 30 to focus all development on a follow-on engine, the HeS 011, a much more advanced (and therefore problematic) design.[citation needed] Meanwhile, the first He 280 prototype had been re-equipped with pulsejets[5] and was towed aloft to test them. Bad weather caused the aircraft to ice up, however, and before the jets could be tested, pilot Helmut Schenk became the first person to put an ejection seat to use. The seat worked perfectly, but the aircraft was lost, and never found.

With the HeS 011 not expected for some time, Heinkel was forced to accept that it would have to use a competitor's engines, and selected the BMW 003. Unfortunately, this engine was also experiencing problems and delays, and in the meantime, the second He 280 prototype was re-engined with Junkers Jumo 004s while the next three airframes were earmarked for the BMW motor (which, in the end, would never be ready before the end of the He 280 project). The Jumo engines were much larger and heavier than the HeS 8 that the plane had been designed for, and while it flew well enough (for the first time on 16 March 1943), it was immediately obvious that this engine would be unsuitable in the long term.[citation needed] The aircraft was slower and generally less efficient than the Me 262.[2]

Less than two weeks later, on 27 March, Erhard Milch cancelled the project. The Jumo 004-powered Me 262 appeared to have most of the qualities of the He 280, but was better matched to its engine. Heinkel was ordered to abandon the He 280 and focus attention on bomber development and construction, something he remained bitter about until his death.[citation needed]

Specifications (He 280 V3)

General characteristics

  • Crew: 1, pilot
  • Length: 10.40 m (34 ft 1 in)
  • Wingspan: 12.20 m (40 ft)
  • Height: 3.06 m (10 ft)
  • Wing area: 21.5 m² (233 ft²)
  • Empty weight: 3,215 kg (7,073 lb)
  • Loaded weight: 4,280 kg (9,416 lb)
  • Max takeoff weight: 4,300 kg (9,470 lb)
  • Powerplant: 2× Heinkel HeS.8 turbojet, 5.9 kN (1,320 lbf) each

Performance

Armament

(Wiki)

NORTH AMERICAN F-107


The North American F-107 was North American Aviation's (NAA) entry in a United States Air Force tactical fighter-bomber design competition of the 1950s. The F-107 incorporated many innovations and radical design features, and was based on the F-100 Super Sabre. The competition was eventually won by the F-105 Thunderchief, and the F-107 prototypes ended their lives as test aircraft

Design and development


A side-view photograph of the F-107A

In June 1953, North American initiated an in-house study of advanced F-100 designs, leading to proposed interceptor (NAA 211: F-100BI denoting "interceptor") and fighter-bomber (NAA 212: F-100B) variants.[2] Concentrating on the F-100B, the preliminary engineering and design work focused on a tactical fighter-bomber configuration, featuring a recessed weapons bay under the fuselage and provision for six hardpoints underneath the wings. Single-point refuelling capability was provided while a retractable tailskid was installed. [3]An all-moving vertical fin and an automated flight control system was incorporated which permitted the aircraft to roll at supersonic speeds using spoilers.[4]The flight control system was upgraded by

the addition of pitch and yaw dampers.[3]

The aircraft's most distinguishing feature is its dorsal-mounted Variable Area Inlet Duct (VAID). While the VAID was a system unique to the F-107A, it was an early form of a variable geometry intake ramp which automatically controlled the amount of air fed to the jet engine.[5] Although the preliminary design of the air intake was originally located in a chin position under the fuselage (an arrangement later adopted for the F-16), the air intake was eventually mounted in an unconventional position directly above and just behind the cockpit.[6] The VAID system proved to be very efficient and NAA used the design concept on their A-5, XB-70 aircraft and XF-108 Rapier designs. [7]

The air intake was in the unusual dorsal location as the USAF had required the carriage of an underbelly semi-conformal nuclear weapon. The original chin intake caused a shock wave that interfered in launching this weapon. The implications this had for the survivability of the pilot during ejection were troubling. It also severely limited view to the rear. Although this was not considered terribly important for a tactical fighter-bomber aircraft, it is characteristic of the era, when it was assumed air combat would be via guided missile exchanges outside visual range. [8]

In August 1954, a contract was signed for three prototypes along with a pre-production order for six additional airframes.[6]

[edit] Designation and names

Extensive design changes resulted in its redesignation from F-100B to F-107A before the first prototype flew. The F-107 was never given an official name, but was sometimes informally called the "Super Super Sabre"[9]referring to North American's earlier fighter design, the F-100 Super Sabre.[10] The flight crews referred to it as the "man eater," in reference to the position of the air intake directly above the cockpit.[11]

The designation "F-107A" was the only one assigned to the aircraft,[12][10]though "YF-107A" is often used in publications.[3][13]

[edit] Operational history

An F-107A in flight

The first F-107A (s/n 55-5118) with North American's chief test pilot Bob Baker at the controls, made its initial flight on 10 September 1956, attaining Mach 1.03.[14]Although successfully carrying out its flight, the brake chute did not deploy, which resulted in a "hot" landing with the nose gear strut breaking.[14] The aircraft first achieved Mach 2 in tests on 3 November 1956.

The second F-107A (s/n 55-5119) made its first flight was on 28 November 1956. It was used for weapons testing with both conventional and atomic bombs. The last prototype, (s/n 55-5120) had its maiden flight on 10 December 1956.

At the conclusion of the F-107A's successful test program, the Tactical Air Command decided to hold a fly-off competition between the F-107A and the Republic F-105 which was designed to same mission requirements and used the same engine. Although the competition was close, the F-105 was selected as the new standard TAC tactical fighter. The three F-107A prototypes were relegated to test flying while the pre-production order was cancelled. [15]

In late 1957, prototypes #1 and #3 were leased to the National Advisory Committee for Aeronautics (NACA) for high-speed flight research, while aircraft #2 was flown on 25 November 1957 to the National Museum of the United States Air Force near Dayton, Ohio. In September 1959, with Scott Crossfield at the controls, aircraft #3 was damaged during an aborted takeoff. The aircraft was not repaired and, ultimately, it was used for fire fighting training and was destroyed in the early '60s.[16]

[edit] Survivors

[edit] Specifications (F-107A)

Data from [18]

General characteristics

  • Crew: 1
  • Length: 61 ft 10 in (18.85 m)
  • Wingspan: 36 ft 7 in (11.15 m)
  • Height: 19 ft 8 in (5.89 m)
  • Wing area: 376 ft² (35 m²)
  • Empty weight: 22,696 lb (10,295 kg)
  • Loaded weight: 39,755 lb (18,033 kg)
  • Max takeoff weight: 41,537 lb (18,841 kg)
  • Powerplant:Pratt & Whitney YJ75-P-9 turbojet, 24,500 lbf (109 kN)

Performance

Armament

  • Bombs: 10,000 lb (4,500 kg)
(WIKIPEDIA)

Wednesday, 23 December 2009

SAUNDERS-ROE PRINCESS, BRIT'S GIGANTIC SEAPLANE


The Saunders-Roe Princess was a British flying boat aircraft built by Saunders-Roe, based in Cowes on the Isle of Wight. The Princess was one of the largest aircraft in existence.

By the 1950s, large, commercial flying boats were being overshadowed by land-based aircraft. Factors such as runway and airport improvements added to the viability of land-based aircraft, which did not have the weight and drag of the boat hulls on seaplanes nor the issues with seawater corrosion.

Design and development

In 1945, Saunders-Roe was asked by the British Ministry of Supply to bid for a long range civil flying boat for British Overseas Airways Corporation (BOAC), who planned to use them on transatlantic passenger services. Saunders-Roe's bid was successful, and it received an order for three aircraft in May 1946.

The Princess was powered by ten Bristol Proteus turboprop engines, powering six propellers. The four inner propellers were double, contra-rotating propellers driven by a twin version of the Proteus, the Bristol Coupled Proteus; each engine drove one of the propellers. The two outer propellers were single and powered by single engines. The rounded, bulbous, 'double-bubble' pressurized fuselage contained two passenger decks, with room for 105 passengers in great comfort.

The ailerons and rudder were split into multiple sections such that if a part of the servo-powered control system failed the faulty section could be "trailed" so that it did not act against the working sections. The planing bottom of the hull had only a slight step in the keel to minimize drag in the air.

Flight testing

In 1951 BOAC changed its mind about its needs and decided it had no requirement for the Princess. It was announced that construction of the three aircraft would continue as transport aircraft for the RAF. However, in March 1952, it was announced that while the first prototype would be completed, the second and third would be suspended to await more powerful engines. The prototype, G-ALUN, first flew on 22 August 1952 and was flown by test pilot Geoffrey Tyson off the Solent. A planed two-three hour flight was curtailed because of erroneous readings on airscrew bearing temperature. Three more flights followed in that week and then it appeared at Farnborough that year.

G-ALUN was the only one to fly - making 46 test flights in total, about 100 hours flying time. It appeared at the Farnborough Airshow in 1953.

Princess Air Transport Co., Ltd was formed with the object of studying the factors affecting the operation of the Princess flying-boats and to tender for their operation should the opportunity have arisen. The Directors were M. D. N. Wyatt (chairman), Sir Archibald Hope, Mr. G. A. V. Tyson, Mr. P. D. Irons and Capt. H. W. C. Alger (general manager). Three-quarters of the share capital were held by Saunders- Roe, Ltd., and one quarter by Airwork, Ltd.

Termination of production

Two other Princesses (G-ALUO and G-ALUP) were built, but they never flew. After a number of years in mothballs, two at Calshot Spit, awaiting further use, NASA considered using them as heavy-duty freight aircraft for transporting Saturn V rocket components. Aquila Airways offered £1 million pounds each for the Princesses in 1954 The nascent Airbus consortium thought of using two for transporting A300 fuselage sections, but opted to use Super Guppies instead. All three Princesses were broken up in 1967.

They were the last fixed-wing commercial aircraft produced by Saunders-Roe. The company built one more fixed-wing design, the Saunders-Roe SR.53 mixed-power (rocket and turbojet) fighter design; aside from that, the company concentrated on helicopters and hovercraft after this point.

Whilst the prototype aircraft had advanced (but conventional) hydraulic controls, S-R intended production aircraft to use an analogue system based around electrical servos with hydraulic final control actuators. Such a system was built and ground-tested, but the Princess project was cancelled before any aircraft was fitted with the system.


Specifications

Data from British Flying Boats and Flight 1952

General characteristics

  • Crew: 2 pilots, 2 flight engineers, radio operator and navigator
  • Capacity: 105 passengers in tourist and first class cabins
  • Length: 148 ft (42.1 m)
  • Wingspan: 219 ft 6 in (66.9 m)
  • Height: 55 ft 9 in (17 m)
  • Wing area: 5,019 sq ft (466 m²)
  • Airfoil: "Saro-modified Goldstein section" to "modified N.A.C.A. 4415 Series" at tip
  • Empty weight: 190,000 lb (86,184 kg)
  • Loaded weight: 330,000 lb (150,000 kg)
  • Max takeoff weight: 345,025 lb (156,500 kg)
  • Powerplant: 10× Bristol Proteus 600/610 turboprop, 2,500 shp (2,386 kW) plus 820 lbf (3.66 kN) jet thrust each
  • Propellers: 4 bladed De Havilland constant-speed, quick-feathering propellers, 1 (inner pairs contrarotating on common axis) per engine
    • Propeller diameter: 16 ft 6 in (5.03 m)
  • *fuel capacity 14,000 Imperial gallons in inner wings

Performance

  • Maximum speed: 330 knots (380 miles per hour (610 km/h)) at 37,000 ft (11,300 m)
  • Cruise speed: 313 knots (360 miles per hour, 580 km/h) at 32500 ft (9,900 m)
  • Stall speed: 98 knots (113 mph, 182 km/h) Flaps down
  • Range: 5,720 miles (4,974 NM, 9,205 km)
  • Service ceiling: 39,000 ft (11,887 m) Absolute ceiling
  • Rate of climb: 1,900 ft/min (579 m/min) at sea level

Tuesday, 22 December 2009

BRISTOL BRABAZON, BRIT'S GIGANTIC AIRLINER



The Bristol Type 167 Brabazon was a large airliner, designed by the Bristol Aeroplane Company to fly transatlantic routes from the United Kingdom to the United States. The prototype was delivered in 1949, only to prove a commercial failure when airlines felt the plane was too large and expensive to be useful. Despite its size, comparable to a Boeing 767, it was designed to carry only 100 passengers, albeit in roomy conditions not generally found on modern aircraft. In the end, only a single prototype was flown; it was broken up in 1953 for scrap, along with an uncompleted second fuselage

Background

In 1943, a British government committee met under the leadership of Lord Brabazon of Tara to investigate the needs of the British civil airliner market.

The Brabazon Committee delivered a report, known as the "Brabazon Report", calling for the construction of four of five designs they had studied. Type I was a large transatlantic airliner, Type III a smaller airliner for the Empire air routes, and Type IV a jet powered 500 mph (800 km/h) airliner. The Type I and IV were considered to be very important to the industry, notably the jet powered Type IV which would give the UK a commanding lead in jet transports.

Bristol had already studied a large bomber design starting as early as 1937, but nothing had come of this. In 1942 the Air Ministry published a tender for a new super-heavy bomber design, and Bristol dusted off their original work and updated it for their newer and much more powerful Bristol Centaurus engines. This led to a design with a range of 5,000 mi (8,000 km), 225 ft (69 m) wing span, eight engines buried in the wings driving four pusher propeller installations, and enough fuel for transatlantic range. This "100 ton bomber" and designs from the other major manufacturers were in many ways the British analogues to the American Convair B-36. However in expectation of long development times, the Air Ministry later changed their mind and decided to continue development of the Avro Lancaster, (leading to the Avro Lincoln) instead.


Testing

The Mk.I aircraft, registration G-AGPW, rolled out for engine runs in December 1948, and flew for the first time, over Avonmouth for 25 minutes, on 4 September 1949 captained by Bristol Chief Test Pilot Bill Pegg. It flew to about 3,000 ft (910 m) at 160 mph (257 km/h) and landed at 115 mph (185 km/h), throttling back at 50 ft (15 m). Four days later, it was presented at the Farnborough Airshow before starting testing in earnest. It was demonstrated at the 1950 Farborough Airshow with a take-off, clean configuration fly-past and a landing. In June 1950, she visited London's Heathrow Airport, making a number of successful takeoffs and landings, and was demonstrated at the 1951 Paris Air Show. By this point, BOAC had lost any interest in the design, if it ever really had any, and although some interest was shown by BEA on flying the prototype itself, various problems that would be expected of a prototype meant it never received an airworthiness certificate.

Cancellation

By 1952, about £3.4m had been spent on development (£53.4m year in year-2000 pounds) and it showed no signs of being purchased by any airline. In March, the British government announced that work on the second prototype had been postponed. The cancellation of the project was announced by the Minister for Supply (Duncan Sandys) on 17 July 1953 in the Commons saying that it had given all the useful technical knowledge it could but with no interest from civil or the military they had no justification for continuing to spend money on it. About 6 million pounds had been spent and a further 2 would be required for the completion of the Mark II. The buildings and runway had cost a further £6 million.[4] In October 1953, after 164 flights totalling 382 hours flying time, the first prototype was broken up, along with the uncompleted Mk.II prototype. All that remains are a few parts at the Bristol Industrial Museum and Scotland's Museum of Flight.

Although considered a failure and a white elephant, the record of the Brabazon is not entirely unfavourable. At least half of the large sums spent on the project were put into infrastructure, including the large hangars and runway at Filton. This meant that Bristol was now in an excellent position to continue production of other designs and the hall was used for building the Britannia aircraft. In addition, many of the techniques developed as a part of the Brabazon project were applicable to any aircraft, not just airliners.

Bristol had also won the contract for the "unimportant" Type III aircraft, which they delivered as the Bristol Britannia. Using all of the advancements of the Brabazon meant the Britannia had the best payload fraction of any aircraft up to that point, and it kept that record for a number of years. Although the Britannia was delayed after problems with the Type IV, the de Havilland Comet, it went on to be a workhorse for many airlines into the 1970s. The Britannia is still considered by many[who?] to be the ultimate propeller driven airliner.[citation needed]

Specifications (Mark I)

Data from Flight

General characteristics

  • Crew: 6-12
  • Capacity: 100 passengers [5]
  • Length: 177 ft (54.0 m)
  • Wingspan: 230 ft (70 m)
  • Height: 50 ft (15 m)
  • Wing area: 5,317 ft² (494.0 m²)
  • Airfoil: Root T.P.4 (mod) Tip T.P.5
  • Empty weight: 145,100 lb (65,820 kg)
  • Max takeoff weight: 290,000 lb (130,000 kg)
  • Powerplant:Bristol Centaurus radial engines, 2,650 hp (1,860 kW) each
  • Propellers: paired contra-rotating 3-bladed Rotol
    • Propeller diameter: 16 ft ()
  • Fuel capacity 13,650 Imp gal

Performance

(wikipedia)

About Centaurus Engines

To achieve the necessary reduction in drag and also achieve the design criteria, i.e. non-stop across the Atlantic with 100 passengers, a serious rethink was needed. Bristol had done some initial design work for the aborted Type 159 long-range bomber. This had been a 100 ton bomber with a range up to 5000 miles.

Analysis of the current designs showed that conventional wing mounted engines accounted for 30% of the overall drag, although only 5% was needed for cooling. It became clear to the design team that power plants completely submerged in the wing were thus likely to reduce total drag by 25%, if technically feasible.

The wing would have to be at least as thick as the height of the engine, and coupling several engines side by side to a single airscrew would leave the outer wing free from interference and available for fuel storage. By using this method the larger range required could be easily achieved.

(www.aviationarchive.org.uk)

MIRAGE G, ONE OF DASSAULT USELESS MIRACLE


The Dassault Mirage G was a French design for a fast swing-wing multirole jet fighter aircraft, capable of both interception and ground attack with a nuclear missile.

A single-engine prototype testing variable-geometry techniques, the basic Mirage G was developed into a twin-engine, two-seat fighter, the Mirage G4. However, as the project continued the requirements were constantly changing, and the French military requested the design be converted into a dedicated interceptor. The single-seat Mirage G8 was an attempt to shed some of the weight and costs associated with swing-wing designs. As development proceeded, costs continued to rise, and mission demands changed, causing the eventual cancellation of the project in the mid-1970s.


Specifications (Mirage G8)

General characteristics

  • Crew: 1
  • Length: 18.80 m (61 ft 8 in)
  • Wingspan:
    • Extended: 15.40 m (50 ft 6 in)
    • Swept: 8.70 m (28 ft 7 in)
  • Height: 5.35 m (17 ft 7 in)
  • Empty weight: 14,740 kg (32,500 lb)
  • Powerplant:SNECMA Atar 9K50 turbojets, 70.1 kN (15,800 lbf) each

Performance

(WIKIPEDIA)

TU144, RUSSIAN ABORTUS CONCORDSKI

The Tupolev Tu-144 (NATO reporting name: "Charger") was one of the world's two supersonic transport aircraft (SST, along with Concorde), constructed under the direction of the Soviet Tupolev design bureau headed by Alexei Tupolev[1].

A prototype (OKB: izdeliye 044 - article 044[1]) first flew on 31 December 1968 near Moscow, two months before the similar Aérospatiale / British Aircraft Corporation Concorde. The Tu-144 first broke the speed of sound on 5 June 1969, and on 15 July 1969 it became the first commercial transport to exceed Mach two. The Tu-144 was introduced into passenger service on 1 November 1977, almost two years later than the Concorde, but was quickly withdrawn only after 55 scheduled passenger flights due to severe problems with aircraft safety and was not re-introduced to service.

The Tu-144 was Tupolev's only supersonic commercial airliner venture. Tupolev's other large supersonic aircraft were designed and built to military specifications. All these aircraft benefited from technical and scientific input from TsAGI, the Central Aerohydrodynamic Institute.

Although the Tu-144 was technically broadly comparable to Concorde, the Tu-144 lacked a passenger market within the Soviet Union and service was halted after only about 100 scheduled flights.

Paris Air Show crash

At the Paris Air Show on 3 June 1973, the development program of the Tu-144 suffered severely when the first Tu-144S production airliner (reg 77102) crashed.[7][8]

While in the air, the Tu-144 underwent a violent downwards maneuver. Trying to pull out of the subsequent dive, the Tu-144 broke up and crashed, destroying 15 houses and killing all six people on board the Tu-144 and eight more on the ground.


The causes of this incident remain controversial to this day. A popular theory was that the Tu-144 was forced to avoid a French Mirage chase plane which was attempting to photograph its canards, which were very advanced for the time, and that the French and Soviet governments colluded with each other to cover up such details. The flight of the Mirage was denied in the original French report of the incident, perhaps because it was engaged in industrial espionage. More recent reports have admitted the existence of the Mirage (and the fact that the Russian crew were not told about the Mirage's flight) though not its role in the crash. However, the official press release did state: "though the inquiry established that there was no real risk of collision between the two aircraft, the Soviet pilot was likely to have been surprised."[9]

Another theory claims that the black box was actually recovered by the Soviets and decoded. The cause of this accident is now thought to be due to changes made by the ground engineering team to the auto-stabilisation input controls prior to the second day of display flights. These changes were intended to allow the Tu-144 to outperform Concorde in the display circuit. Unfortunately, the changes also inadvertently connected some factory-test wiring which resulted in an excessive rate of climb, leading to the stall and subsequent crash.[10]

A third theory relates to deliberate misinformation on the part of the Anglo-French team. The main thrust of this theory was that the Anglo-French team knew that the Soviet team were planning to steal the design plans of Concorde, and the Soviets were allegedly passed false blueprints with a flawed design. The case, it is claimed, contributed to the imprisonment by the Soviets of Greville Wynne in 1963 for spying.[11][12] Wynne was imprisoned on 11 May 1963 and the development of the Tu-144 was not sanctioned until 16 July. In any case, it seems unlikely that a man imprisoned in 1963 could have caused a crash in 1973.

Operational service

Tu-144 with distinctive Droop-nose at the MAKS-2007 exhibition

The Tu-144S went into service on 26 December 1975, flying mail and freight between Moscow and Alma-Ata in preparation for passenger services, which commenced in November 1977 and ran a semi-scheduled service until the first Tu-144D experienced an in-flight failure during a pre-delivery test flight, and crash-landed with crew fatalities on 23 May 1978 [13]. The Aeroflot flight on 1 June 1978 was the Tu-144's 55th and last scheduled passenger service.

A scheduled Aeroflot freight-only service recommenced using the new production variant Tu-144D (Dal'nyaya - long range[14]) aircraft on 23 June 1979, including longer routes from Moscow to Khabarovsk made possible by the more efficient Kolesov RD-36-51 turbojet engines used in the Tu-144D version, which increased the maximum cruising speed to Mach 2.15.[15] Including the 55 passenger flights, there were 102 scheduled Aeroflot flights before the cessation of commercial service.

It is known that Aeroflot still continued to fly the Tu-144D after the official end of service, with some additional non-scheduled flights through the 1980s. One report showed that it was used on a flight from the Crimea to Kiev in 1987

(WIKIPEDIA)

Monday, 21 December 2009

BOEING 2707, US ABORTED CONCORDE




Early studies

Boeing had worked on a number of small-scale SST studies since 1952. In 1958, it established a permanent research committee, which grew to a $1 million effort by 1960. The committee proposed a variety of alternative designs, all under the name Model 733. Most of the designs featured a large delta wing, but in 1959 another design was offered as an offshoot of Boeing's efforts in the swing-wing TFX project (which led to the purchase of the General Dynamics F-111 instead of the Boeing offering). In 1960, an internal "competition" was run on a baseline 150-seat aircraft for trans-Atlantic routes, and the swing-wing version won.[1]

By mid-1962, it was becoming clear that tentative talks earlier that year between the Bristol Aeroplane Company and Sud Aviation on a merger of their SST projects were more serious than originally thought. It appeared there was a very real chance the combined companies would be offering a design. In November, the two companies announced that a design called "Concorde" would be built by a consortium effort. This set off something of a wave of panic in other countries, as it was widely believed that almost all future commercial aircraft would be supersonic, and it looked like the Europeans would start off with a huge lead.

Government funding cut

In March 1971, despite the project's strong support by the administration of President Richard Nixon, the U.S. Senate rejected further funding. Afterward, letters of support from aviation buffs, containing nearly $1 million worth of contributions, poured in. The SST project was canceled on May 20, 1971. At the time, there were 115 unfilled orders by 25 airlines; at the time, Concorde had 74 orders from 16 customers.[2] The two prototypes were never completed. The SST became known as "the airplane that almost ate Seattle." Due to the loss of several government contracts and a downturn in the civilian aviation market, Boeing reduced its number of employees by more than 60,000. A billboard was erected in 1971 that read, "Will the last person leaving Seattle - turn out the lights"[3]

Legacy

North American Rockwell's B-1[4] used a similar layout to the 733-197's. The B-1 is the only swing-wing aircraft still in service with US forces.

Seattle's NBA basketball team formed in 1968 was dubbed the Seattle SuperSonics or just "Sonics", a name inspired by the newly won SST contract.[5] The team kept that name until its 2008 move to Oklahoma City, and Seattle holds the right to apply the name to any future NBA franchise there.

The Museum of Flight in Seattle parks its Concorde a few blocks from the building where the original mockup was housed in Seattle.[6] While the Soviet Tu-144 had a short service life,[7] Concorde was successful enough to fly as a small luxury fleet from 1976 until 2003. As the most advanced supersonic transports became some of the oldest airframes in the fleet, they also fell to the economics of new efficient subsonic jets and upgrade costs.[8]

Though many designs have been studied since, it is unlikely similar aircraft will be economically feasible in the foreseeable future. Concorde's model of cooperation paved the way for Airbus, Boeing's most formidable competitor.[9] Seattle's economy is now more diverse, and 2007 made Boeing a leader in sales again. Boeing's Future of Flight museum has the story and models of all of its production jetliners and Concorde, but not the SST project.

One of the wooden mockups was displayed at the SST Aviation Exhibit Center in Kissimmee, Florida from 1973 to 1981. It is now on display at the Hiller Aviation Museum of San Carlos, California.[10]

Airline commitments

[edit] Specifications

Model Boeing 2707-200 SST
Wingspan 180 feet 4 inches (54.97 m) spread, 105 feet 9 inches (32.23 m) swept.
Length 306 feet 0 inches (93.27 m)
Height 46 feet 3 inches (14.10 m)
Takeoff length 5,700 feet (1,700 m)
Landing length 6,500 feet (2,000 m)
Fuselage max. external dimensions Width 16 feet 8 inches (5.08 m), depth 15 feet 7 inches (4.75 m)
Engines (4x) General Electric GE4/J5P turbojets, 63,200 lbf (281 kN) each, with augmentation.
Empty operating weight International model: 287,500 pounds (130,400 kg)
Max. ramp weight 675,000 pounds (306,000 kg)
Max. landing weight 430,000 pounds (200,000 kg)
Max. payload: 75,000 pounds (34,000 kg)
Normal cruising speed Mach 2.7: 1,800 miles per hour (2,900 km/h) at 64,000 feet (20,000 m)
Range 4,250 miles (6,840 km) with 277 passengers

Friday, 18 December 2009

BAC TSR-2, British Govt.'s Blunder



The British Aircraft Corporation TSR-2 was an ill-fated Cold War strike aircraft developed by the British Aircraft Corporation (BAC) for the Royal Air Force (RAF) in the early 1960s. The TSR-2 was designed to penetrate a well-defended forward battle area at low altitudes and very high speeds, and then attack high-value targets in the rear with close-in bomb runs and precision drops. The TSR-2 included a number of advanced features that made it the highest performing aircraft in this role, yet the programme was controversially cancelled in favour of the General Dynamics F-111, a procurement that itself was later cancelled.

All modern aircraft have four dimensions: span, length, height and politics. TSR-2 simply got the first three right.

The mission

The envisioned "standard mission" for the TSR-2 was to carry a 2,000 lb (900 kg) weapon internally for a combat radius of 1,000 nautical miles (nm) (1,850 km). Of that mission 100 nm (185 km) was to be flown at higher altitudes at Mach 1.7 and the 200 nm (370 km) into and out of the target area was to be flown as low as 200 feet (60 m) at Mach 0.95. The rest of the mission was to be flown at Mach 0.92. If the entire mission were to be flown at the low 200-ft altitude, the mission radius was reduced to 700 nm (1,300 km). Heavier weapons loads could be carried with further reductions in range.

Extensions to the TSR-2's range were planned to be made by fitting external tanks — one 450-Imperial gallon (2,000 L) tank under each wing or one 1,000 Imperial gallon (4,500 L) tank carried centrally below the fuselage. If no internal weapons were carried, a further 570 Imperial gallons (2,600 L) could be carried in a tank in the weapons bay.

Planned flight profiles - as of 3rd December 1963.

It was also planned to be able to equip the TSR-2 with a reconnaissance pack in the weapons bay which, coupled to the aircraft's capable sideways looking radar (SLR), would have turned the aircraft into a formidable "recon" asset not unlike the contemporary North American RA-5C of the United States Navy.

Design

TSR-2 prototype XR219 on its maiden flight

English Electric, manufacturer of the Canberra, and Vickers-Armstrongs had been judged to have made the best submissions for GOR.339. The two companies combined their ideas for the specification and put forward their joint design with a view to an aircraft flying by 1963. No order was forthcoming, and by the time the Ministry had made a decision the various companies had been amalgamated as the British Aircraft Corporation in 1960. EE had put forward a delta winged design and Vickers a swept wing on a long fuselage. The EE wing, born of their greater supersonic experience, was judged superior to Vickers, while the Vickers fuselage was preferred. In effect, the aircraft would be built 50/50: Vickers the front half, EE the rear.[1]

The design was a large aircraft, to be powered by two Bristol-Siddeley Olympus afterburning turbojets, with a large shoulder-mounted slab-wing with down-turned tips, an all-moving swept tailplane and a large all-moving fin. The engines were a development of those used in the Avro Vulcan, and would later be developed further for Concorde.

The design featured blown flaps across the entire trailing edge of the wing to achieve the short takeoff and landing requirement, something that later designs would achieve with the technically more complex swing-wing approach. Roll control was by differential movement of the tailplanes, i.e., tailerons. The aircraft featured some extremely sophisticated avionics for navigation and mission delivery — far ahead of anything else available at the time — which would also prove to be one of the reasons for the spiralling costs of the project. Some features, such as forward looking radar (FLR) for terrain clearance, side-looking radar for mapping and the sophisticated autopilot, only became commonplace on military aircraft later.

The wing loading was high for its time, enabling the aircraft to fly at very high speed and low level with great stability without being constantly upset by thermals and other ground-related weather phenomena. This in turn made the innovative terrain clearance and autopilot system feasible.

There were considerable problems with realizing the design. Some contributing manufacturers were employed directly by the Ministry rather than through BAC, and the Ministry itself took on design tasks, with the usual long deliberations and meetings typical of civil servants.

Specifications

General characteristics

  • Crew: 2
  • Length: 89 ft ½ in (27.12 m)
  • Wingspan: 37 ft 1¾ in (11.27 m)
  • Height: 23 ft 9 in (7.24 m)
  • Wing area: 702.9 ft² (65.3 m²)
  • Empty weight: 54,750 lb (24,834 kg)
  • Loaded weight: 79,573 lb (36,169 kg)
  • Max takeoff weight: 102,200 lb (46,357 kg)
  • Powerplant:Bristol-Siddeley Olympus BOl.22R (Mk. 320) turbojet
    • Dry thrust: 19,610 lb (87.23 kN) each
    • Thrust with afterburner: 30,610 lbf (136.7 kN) each

Performance

Armament

  • Internal weapons bay, 20 ft (6 m) with (initially) 1 Red Beard 15kt nuclear weapon or as intended 2 x OR.1177 300kt nuclear weapons (cancelled) or 6 x 1,000 lb (450 kg) HE bombs. Final designed normal load in nuclear role of 4 x WE.177A nuclear weapons, two side-by-side in weapons bay, two on external underwing stores pylons.
  • or 4 x 37 rocket packs or nuclear weaponry on inner pylons only.


Maximum of 20,000 lbs (9,000 kg) of bombs.

Avionics

(wikipedia)