M21 Aircraft - The Lockheed D-21 is an American supersonic surveillance drone. The D-21 was originally designed to launch from the rear of the M-21 aircraft carrier, a variant of the Lockheed A-12 aircraft. The drone has a top speed of Mach 3.3 (2,200 miles per hour; 3,600 kilometers per hour) at an operating altitude of 90,000 feet (27,000 meters). Development began in October 1962. Originally called the Lockheed Q-12, the drone was designed for deep-space surveillance.
The D-21 is designed to carry a high-resolution photo camera along a pre-programmed path, releasing the camera module into the air for recovery, after which the drone self-destructs.
M21 Aircraft
After a fatal accident launched from the M-21, the D-21 was modified to be launched from the Boeing B-52 Stratofortress. Several test flights were flown before the program was canceled in 1971, followed by four unsuccessful D-21 operational flights over the People's Republic of China.
File:pzl M21 Dromedar Ott2013 D7n9048 001.jpg
In the 1960s, Lockheed's secret Skunk Works developed the Mach 3 A-12 surveillance aircraft for the Central Intelligence Agency (CIA). After the downing of the U-2 piloted by Gary Powers in 1960, various concepts were proposed as alternatives. Kelly Johnson, leader of Skunk Works, developed a long-range drone concept that heavily leveraged the A-12's technology. In October 1962, the CIA and the United States Air Force (USAF) commissioned Lockheed to study a high-speed, high-altitude drone concept. Johnson claimed a speed of Mach 3.3–3.5, an operating altitude of 87,000–95,000 ft (27,000–29,000 m) and a range of 3,000 nautical miles (3,500 mi; 5,600). km). It was intended to make a one-way trip, eject the camera payload on the day of the recovery mission, and self-destruct.
It has a double delta wing similar to the A-12 wing design. The Q-12 was to be launched into the air from behind the A-12 and used key technology from the A-12 project, including titanium construction and reduced radar cross-section design features.
A rear view of the D-21 and M-21 combination on the ground, showing the exhaust deck used in early flights
Johnson wanted to power the Q-12 with a Marquard Corporation-designed jet engine for the Boeing CIM-10 Bomarc long-range surface-to-air missile. Marquardt and Lockheed have already collaborated on several initiatives and have a close working relationship. The RJ43-MA-11 engine required modifications because the missile was designed to fire only when needed to hit the target, while the Q-12's engine could run at high temperatures for at least an hour and a half. height The revised engine was designated RJ43-MA20S-4.
Handley Page Hp 115
A full-scale mock-up of the Q-12 was ready by 7 December 1962, and preliminary tests had already been carried out to measure its radar cross-section. Meanwhile, Marquardt successfully tested a modified RJ-43 in his wind tunnel.
However, the CIA was less than enthusiastic about the Q-12, especially since the AG was overstretched at the time with U-2 missions, bringing the A-12 to rapid and covert operations in Southeast Asia. The USAF, however, became interested in the Q-12 as a surveillance platform and cruise missile, and the CIA eventually decided to work with the USAF to develop a new drone. Lockheed was awarded the contract in March 1963 for full-scale development of the Q-12.
The camera and its film magazines are carried in a narrow "Q-bay" below the drone's air intake with an inertial navigation system. These parts are included in a module that fits into the bay and is called a "hatch". The hatch is ejected late in the mission and held airborne by the JC-130 Hercules, developed by the USAF to retrieve film canisters from satellites. If the C-130 fails, the hatch is equipped with flotation devices so that it can be retrieved by a ship if released on water. Honeywell builds avionics systems; New construction techniques and materials had to be developed for the systems to withstand the high temperatures, extreme vibrations and lack of space in the D-21.
In late 1963 the project was named Tagboard; The Q-12 was re-designated the D-21, while the A-12 version's launcher became the M-21 (D- for "daughter" and M- for "mother"). Two of the original 18 A-12 aircraft were designated as M-21s with serial numbers 60-6940 and 60-6941. The M-21 is a two-seat version of the A-12, with a pylon in the fuselage line between the vertical stabilizers to carry the drone nose up.
Ultrasonic Research Aircraft Fairey Delta 2
The D-21 began captive flight testing on 22 December 1964, mounted on the M-21. Aero fairings were initially placed on the intake and exhaust of the D-21 to reduce drag, but these had to be removed after the first tests. No way has been devised to discard them at Mach 3 without damaging the drone or carrier aircraft.
The drone was released but remained close behind the M-21 for a few seconds, which seemed like "two hours" to the M-21 crew.
The second launch took place on April 27, 1966; The D-21 reached its operating altitude of 90,000 ft (27,000 m) and a speed in excess of Mach 3.3 (2,200 mph; 3,600 km/h), although it was lost due to hydraulic pump failure after more than 1,200 sorties. nmi (1,400 mi; 2,200 km). USAF interest in the program continued, and more D-21s were ordered after the second launch.
A third flight took place on 16 June when the D-21 flew through its full flight profile at 1,550 nmi (1,800 mi; 2,900 km), but its camera failed to release due to an electronic failure.
Air & Space Museum Annex And Luray Caverns
The fourth and final launch from M-21 on July 30 was a disaster. Unlike the previous three launches, this one was performed straight and level rather than on an external loop to help separate the drone from the aircraft. The D-21 suffered engine trouble and struck the tail of the M-21 after breaking away, resulting in the destruction of both aircraft. Both the crew ejected and landed in the sea. The pilot, Bill Park, survived, but the launch control officer, Ray Torrick, drowned.
After the crash, Johnson suggested launching the D-21 from a Boeing B-52 Stratoforres bomber and attaching a solid rocket booster to get it up and running.
The drone was modified by adding attachment points to its spine to mate with the B-52's cargo pylon, and changing its belly attachment points to accommodate the rocket booster needed to increase its speed and operate its ramjet. Its vertical stabilizer has increased in size by about 20%. A modified version of the drone was designated the D-21B (no D-21A). Two B-52Hs were modified to carry drones each using two large underwing pylons in place of the smaller pylons used for AGM-28 Hound Dog cruise missiles. Two launch control stations replaced the tail gunner and electronic warfare officer stations. Command and telemetry systems were added, and high-speed cameras were installed to track the drones as they detached from the pylons. The B-52H's launch control officer was able to communicate with the D-21B and cause it to self-destruct.
A solid propellant rocket booster is larger and heavier than a drone; It was 44 feet 4 inches (14 m) long and weighed 13,286 pounds (6,000 kg). It has a folding tail fin at the bottom to stabilize the rocket while firing. The booster has a burn time of 87 seconds and a thrust of 27,300 lbf (121 kN).
Lockheed Sr 71 (a 12/yf 12/d 21) (aerofax Minigraph 1)
During ground handling, everyone within 25 feet (7.6 m) must wear antistatic straps to prevent the discharge of static electricity that could ignite the booster.
The D-21B's first launch attempt took place on September 28, 1967, but the drone fell from the B-52's launch tower due to a loosened nut on the tower before the aircraft reached the launch point. Johnson admitted the incident was "very embarrassing." Three more experiments were conducted from November 1967 to January 1968. None were entirely successful, so Johnson ordered his team to thoroughly review the launch efforts before rethinking them.
The next launch was on April 10, 1968. It also failed as the engine did not fire. On June 16 the D-21B finally made its first successful flight; It flew at the specified altitude and passed across its range and the hatch was retrieved.
The next two launches failed, followed by another successful flight in December. A test in February 1969 to check the inertial navigation system using the original mission profile failed. The next two flights in May and July were successful.
Aviation Photographs Of Registration: M21 04
Four operational missions with the D-21B were flown under the Sear Bowl code. They were deployed in the People's Republic of China from 9 November 1969 to 20 March 1971 to monitor the Lop Nor nuclear test site. The USAF's 4200th Support Squadron, based at Beale Air Force Base, California, normally flies missions from Anders Air Force Base, Guam.
The Chinese government has never reported sightings of the D-21B in flight. The first did not turn and
Oxygen bottle in aircraft, lru page replacement algorithm in c, lru algorithm in os, lru in c, magneto in aircraft, aircraft lru, lru algorithm in c, lru replacement algorithm in c, electrical systems in aircraft, aircraft manufacturers in florida, composite in aircraft, pressure instruments in aircraft
0 Comments