1984 жылғы Boeing 720 ұшағының қаусап құлау сынағы

1984 crash test of a Boeing 720, carried out by NASA and the FAA

The Controlled Impact Demonstration (or colloquially the Crash In the Desert) was a joint project between NASA and the Federal Aviation Administration (FAA) that intentionally crashed a remotely controlled Boeing 720 aircraft to acquire data and test new technologies to aid passenger and crew survival. The crash required more than four years of preparation by NASA Ames Research Center, Langley Research Center, Dryden Flight Research Center, the FAA, and General Electric. After numerous test runs, the plane was crashed on December 1, 1984. The test went generally according to plan, and produced a large fireball that required more than an hour to extinguish. The FAA concluded that about one quarter of the passengers would have survived, that the antimisting kerosene test fuel did not sufficiently reduce the risk of fire, and that several changes to equipment in the passenger compartment of aircraft were needed. NASA concluded that a head up display and microwave landing system would have helped the pilot more safely fly the aircraft.

NASA and the Federal Aviation Administration (FAA) conducted a joint program for the acquisition, demonstration, and validation of technology for the improvement of transport aircraft occupant crash survivability using a large, four engine, remotely piloted transport airplane in a controlled impact demonstration (CID). The CID program was conducted at the Dryden Flight Research Facility of NASA Ames Research Center (Ames Dryden), at Edwards, California, using a remotely controlled Boeing 720 transport, and was completed in late 1984. The objectives of the CID program were to demonstrate a reduction of postcrash fire through the use of antimisting fuel, acquire transport crash structural data, and to demonstrate the effectiveness of existing improved seat restraint and cabin structural systems. The Boeing 720 (tail number N833NA After more than 20,000 hours and 54,000 takeoff and landing cycles, it had come to the end of its useful life. degrading the fuel and igniting it after impact, providing a significant heat source. The fire and smoke took over an hour to extinguish. The CID impact was spectacular with a large fireball created by the number 3 engine on the right side, enveloping and burning the aircraft. From the standpoint of AMK the test was a major setback. For NASA Langley, the data collected on crashworthiness was deemed successful and just as important.

The actual impact demonstrated that the antimisting additive tested was not sufficient to prevent a post crash fire in all circumstances, though the reduced intensity of the initial fire was attributed to the effect of AMK. FAA investigators estimated that 23–25% of the aircraft's full complement of 113 people could have survived the crash. Time from slide out to complete smoke obscuration for the forward cabin was 5 seconds; for the aft cabin, it was 20 seconds. Total time to evacuate was 15 and 33 seconds respectively, accounting for the time necessary to reach and open the doors and operate the slide. Investigators labeled their estimate of the ability to escape through dense smoke as "highly speculative". As a result of analysis of the crash, the FAA instituted new flammability standards for seat cushions which required the use of fire blocking layers, resulting in seats which performed better than those in the test. It also implemented a standard requiring floor proximity lighting to be mechanically fastened, due to the apparent detachment of two types of adhesive fastened emergency lights during the impact. Federal aviation regulations for flight data recorder sampling rates for pitch, roll and acceleration were found to be insufficient. NASA concluded that the impact piloting task was of an unusually high workload, which might have been reduced through the use of a heads up display, the automation of more tasks, and a higher resolution monitor. It also recommended the use of a microwave landing system to improve tracking accuracy over the standard instrument landing system. In practice, the Global Positioning System based Wide Area Augmentation System came to fulfill this role.