The Fairey Delta 2 high-speed experimental aircraft, which had a droop nose that included its cockpit
The droop nose is a feature fitted to a small number of aircraft types so the nose of the aircraft can be lowered during takeoff and landing to improve the pilot's view of the ground below. This feature is used with a very-low aspect ratio wing such as a delta wing. It is installed in aircraft capable of supersonic speeds but is lowered only during low-speed operation such as takeoff and landing.
The first supersonic delta to receive a drooped nose was the Fairey Delta 2, a British experimental high-speed aircraft. Nicknamed "Droop Snoot",[1] the Delta2 featured a relatively long tapered nose, which smoothly flowed into its cylindrical cross-section fuselage, to generate a high level of aerodynamic efficiency.[2] It was recognised that such a lengthy nose would negatively impact the pilot's forward vision during landing, take-off and ground movements; thus, to retain the aerodynamically optimised nose cone while also providing adequate downwards visibility, the drooped nose was devised. Accordingly, the nose section of the Delta2, including the cockpit, could be drooped by 10° using a hydraulically actuated mechanism. A similar arrangement was subsequently adopted on Concorde.[3][4]
The Delta 2 soundly demonstrated its favourable high-speed performance qualities during flight testing; rapidly proving to be faster than any other British-built aircraft in existence of that time.[5] On 10March 1956, the Fairey Delta2 broke the world airspeed record, raising it to 1,132mph (1,811km/h) or Mach1.73.[3][6][7] Thus, the Delta 2 became the first aircraft to exceed 1,000 miles per hour (1,600km/h).[8] Around this time, Fairey sought to produce a straightforward fighter derivative of the Delta2 that retained many of its features, with efforts largely centering around Operational Requirement F.155. On 1April 1957, Fairey were informed by officials within the Ministry of Supply that their proposals were the favourite to meet Operational Requirement F.155.[9] However, on 4April 1957, Duncan Sandys, the Minister of Defence, announced the effective termination of nearly all fighter aircraft development for the RAF, instantly removing the F.155 requirement.[9]
The Delta 2 became a key development platform for what would later be known as Concorde, an early supersonic airliner, which harnessed a cutting-edge ogee or ogival delta wing design. It was decided to convert one of the two Delta2 aircraft into a testbed for the ogival wing shape. Re-designated as the BAC 221, much of the airframe apart from the wing remained unaltered, the droop nose being one of the features that was carried over.[10][11] The BAC 221 was used for varied flight testing from 1964 until 1973, after which it was placed on public display.[12]
Concorde was furnished with a droop nose, which was developed and manufactured under contract by Marshall's of Cambridge by a team led by Norman Harry OBE.[13] Needing to endure temperatures in excess of 100°C (210°F) at supersonic flight, the nose window and visor glass were developed by Triplex.[14] The droop nose enabled the airliner to switch between being streamlined to reduce drag for optimal aerodynamic efficiency and not obstructing the pilot's view during taxi, take-off, and landing operations.[13]
Concorde's droop nose was accompanied by a moving transparent visor that retracted into the nose prior to being lowered. When the nose was raised to horizontal, the visor would rise in front of the cockpit windscreen for aerodynamic streamlining.[13] A controller in the cockpit allowed the visor to be retracted and the nose to be lowered to 5° below the standard horizontal position for taxiing and take-off. Following take-off and after clearing the airport, the nose and visor were raised. Prior to landing, the visor was again retracted and the nose lowered to 12.5° below horizontal for maximal visibility. Upon landing, the nose was raised to the 5° position to avoid the possibility of damage.[13] There was also a standby droop system if the main system failed, operated from the cockpit central console, and as a last resort if both hydraulic systems failed, a lever could be pulled in the cockpit to release the mechanical latches, allowing the nose to fall under gravity to the 12.5° position.
A front-on view of the Tupolev Tu-144 on the ground. Note the deployed retractable canards and lowered droop nose
The Tupolev Tu-144, a contemporary counterpart to Concorde that was developed by the Soviet Union, also featured a droop nose. Its configuration was not identical to that of Concorde however as the visor of the Tu-144 was fixed to the nose. The Tu-144 exhibited a noticeable tendency for the nose to pitch downward, which was cancelled out via the addition of retractable canards that would deploy when the nose was lowered; the landing speed of the Tu-144s was around 315–333km/h (196–207mph; 170–180kn), which remained higher than that of Concorde.[15]
The Soviet Union also developed a prototype Mach3 strategic bomber, the Sukhoi T-4, that functioned as the Soviet counterpart to America's North American XB-70 Valkyrie. The T-4 featured a sizable droop nose, which completely covered the cockpit windscreen when raised; a periscope was provided for the pilots to obtain forward visibility.[16]
Concorde is a retired Anglo-French supersonic airliner jointly developed and manufactured by Sud Aviation and the British Aircraft Corporation (BAC). Studies started in 1954, and France and the UK signed a treaty establishing the development project on 29 November 1962, as the programme cost was estimated at £70 million . Construction of the six prototypes began in February 1965, and the first flight took off from Toulouse on 2 March 1969. The market was predicted for 350 aircraft, and the manufacturers received up to 100 option orders from many major airlines. On 9 October 1975, it received its French Certificate of Airworthiness, and from the UK CAA on 5 December.
The Tupolev Tu-144 is a Soviet supersonic passenger airliner designed by Tupolev in operation from 1968 to 1999.
A delta wing is a wing shaped in the form of a triangle. It is named for its similarity in shape to the Greek uppercase letter delta (Δ).
The Boeing 2707 was an American supersonic passenger airliner project during the 1960s. After winning a competition for a government-funded contract to build an American supersonic airliner, Boeing began development at its facilities in Seattle, Washington. The design emerged as a large aircraft with seating for 250 to 300 passengers and cruise speeds of approximately Mach 3. It was intended to be much larger and faster than competing supersonic transport (SST) designs such as Concorde.
A supersonic transport (SST) or a supersonic airliner is a civilian supersonic aircraft designed to transport passengers at speeds greater than the speed of sound. To date, the only SSTs to see regular service have been Concorde and the Tupolev Tu-144. The last passenger flight of the Tu-144 was in June 1978 and it was last flown in 1999 by NASA. Concorde's last commercial flight was in October 2003, with a November 26, 2003 ferry flight being its last airborne operation. Following the permanent cessation of flying by Concorde, there are no remaining SSTs in commercial service. Several companies have each proposed a supersonic business jet, which may bring supersonic transport back again.
The Lockheed L-2000 was Lockheed Corporation's entry in a government-funded competition to build the United States' first supersonic airliner in the 1960s. The L-2000 lost the contract to the Boeing 2707, but that competing design was ultimately canceled for political, environmental and economic reasons.
Supercruise is sustained supersonic flight of a supersonic aircraft without using afterburner. Many supersonic military aircraft are not capable of supercruise and can maintain Mach 1+ flight only in short bursts with afterburners. Aircraft such as the SR-71 Blackbird are designed to cruise at supersonic speed with afterburners enabled.
The Bristol Type 223 was an early design for a supersonic transport. In the late 1950s and early 1960s the Bristol Aeroplane Company studied a number of models as part of a large British inter-company effort funded by the government. These models eventually culminated in the Type 223, a transatlantic transport for about 100 passengers at a speed around Mach 2. At about the same time Sud Aviation in France was developing the similar Super-Caravelle design, and in November 1962 the efforts were merged to create the Concorde project.
A variable-sweep wing, colloquially known as a "swing wing", is an airplane wing, or set of wings, that may be swept back and then returned to its original straight position during flight. It allows the aircraft's shape to be modified in flight, and is therefore an example of a variable-geometry aircraft.
Elevons or tailerons are aircraft control surfaces that combine the functions of the elevator and the aileron, hence the name. They are frequently used on tailless aircraft such as flying wings. An elevon that is not part of the main wing, but instead is a separate tail surface, is a stabilator.
The Sukhoi Su-15 is a twinjet supersonic interceptor aircraft developed by the Soviet Union. It entered service in 1965 and remained one of the front-line designs into the 1990s. The Su-15 was designed to replace the Sukhoi Su-11 and Sukhoi Su-9, which were becoming obsolete as NATO introduced newer and more capable strategic bombers.
The Fairey Delta 2 or FD2 is a British supersonic research aircraft that was produced by the Fairey Aviation Company in response to a specification from the Ministry of Supply for a specialised aircraft for conducting investigations into flight and control at transonic and supersonic speeds. Features included a delta wing and a drooped nose. On 6 October 1954, the Delta 2 made its maiden flight, flown by Fairey test pilot Peter Twiss; two aircraft would be produced. The Delta 2 was the final aircraft to be produced by Fairey as an independent manufacturer.
A supersonic aircraft is an aircraft capable of supersonic flight, that is, flying faster than the speed of sound. Supersonic aircraft were developed in the second half of the twentieth century. Supersonic aircraft have been used for research and military purposes, but only two supersonic aircraft, the Tupolev Tu-144 and the Concorde, ever entered service for civil use as airliners. Fighter jets are the most common example of supersonic aircraft.
The Avro 730 was a planned Mach 3 reconnaissance aircraft and strategic bomber that was being developed by Avro Aircraft for the Royal Air Force (RAF). It had been originally envisioned as a very high-speed aircraft to perform aerial reconnaissance missions, conforming with the requirements of Air Ministry Specification OR.330. Avro subsequently decided to modify the design of the proposed 730 in order to accommodate its arming with nuclear weapons; this change therefore meant that the type would be able to perform the nuclear weapons delivery mission as well, which had been called for under Air Ministry Specification RB.156T which sought a high speed reconnaissance-bomber aircraft.
The Tupolev Tu-244 was a proposed supersonic transport (SST) aircraft, developed from the Tu-144. It implemented novel features such as cryogenic fuel to enable flight distances of up to 10,000 km (6,200 mi) and would have carried up to 300 passengers. The project was cancelled in 1993.
The Handley Page HP.115 was an experimental delta wing aircraft designed and produced by the British aircraft manufacturer Handley Page. It was built to test the low-speed handling characteristics to be expected from the slender delta configuration anticipated for a future supersonic airliner.
In aeronautics, a tailless aircraft is an aircraft with no other horizontal aerodynamic surface besides its main wing. It may still have a fuselage, vertical tail fin, and/or vertical rudder.
The High Speed Civil Transport (HSCT) was the focus of the NASA High-Speed Research (HSR) program, which intended to develop the technology needed to design and build a supersonic transport that would be environmentally acceptable and economically feasible. The aircraft was to be a future supersonic passenger aircraft, baselined to cruise at Mach 2.4, or more than twice the speed of sound. The project started in 1990 and ended in 1999.
The Avion de Transport Supersonique Futur (ATSF) also known as Alliance, was a concept design for supersonic transport that was being worked on by both British Aerospace and Aérospatiale. The aircraft was to be based on the experience learned from the supersonic Concorde, and was to fly at a top speed of roughly Mach 2. Preliminary designs were produced, with some wind-tunnel testing of small-scale models, but development apparently stalled in the early 2000s.
Wood, Derek. Project Cancelled. Macdonald and Jane's Publishers, 1975. ISBN0-356-08109-5.
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