Lufthansa Flight 2904

Image of the crash site

Lufthansa Flight 2904 was a scheduled flight of Lufthansa from Frankfurt am Main Airport to Warsaw. On 14 September 1993, the employed that day Airbus A320 -211 crashed on landing at the Warsaw Chopin Airport. Through a series of several factors a go-around should have been made, the machine slipped, however beyond the end of the runway and went after the collision on a mound in flames. Two people on board were killed.

Aircraft

The machine used was an Airbus A320 -211 with the registration D - AIPN and the name " Kulmbach ", factory number 105 He was re- delivered on 10 April 1990 to Lufthansa and operated continuously until the accident just over three years later of this. According to the accident was written largely destroyed the machine.

Accident sequence

After the A320 had a smooth flight, the pilot was informed by the local approach control in Warsaw at 15:28 clock that other pilots reported wind shear near the ground. For the landing runway was 11 with 2800 meters length.

The right main landing gear of the machine was only after 770 meters the first contact with the ground, the left landing gear after 1525 meters. From the first contact with the ground, the pilot -operated wheel brakes, which, however, due to insufficient adhesion did not attack on the wet runway. Only after the placement of the left landing gear the program of fly-by -wire system released the spoilers and reverse thrust as brake systems. The machine had now still a speed of 154 knots (285 km / h). The spoilers were characterized after 1679 meters fully extended at 148 knots. The full reverse thrust could be achieved even after exactly 1900 meters at still 132 knots.

The available remaining distance was enough now not to a go-around, yet because of the wet web, it was possible to bring the aircraft in front of the mound behind the end of the runway to a stop. The pilot therefore moved the machine to the right, so that they at a speed of 58 knots (107 km / h) with the left wing bounced first. Then slid the machine part on the mound, broke and went up in flames, as the left engine was destroyed. The Prüfkapitän located on the right cockpit seat was in the cockpit by internal injuries killed, which he had suffered on impact with the left arm of his seat. One passenger died of smoke inhalation, probably because he - hampered by a vertebral fracture - could not save himself. Another 54 passengers were injured taken to hospitals around. Eight people were treated as outpatients.

Causes

The cause of this accident investigation report considers a combination of factors that:

• One reason lies with more errors the cockpit crew. So she had the sudden onset of wind shear neither adequately considered nor discussed, among other things. In addition, the radio leading pilot had the flying pilot does not explicitly warned against the wind shear component of more than 10 knots, although it recommends the operating manual for the A320. The crew had (still within the landing zone of the runway ) initiated after putting no go-around, although it would have been appropriate and possible.
• The crew of the Towers in Warsaw, is charged in the accident investigation report. They possessed no weather data because the wind information only arrived late at the Tower.
• Furthermore, have contributed to the inadequate description of the braking system in the instructions for operation of the aircraft to the failure of the landing: The pilots would have chosen before fitting an automatic braking process which only initiates the braking maneuver if the machine had been contact with the ground. However, at the level of contemporary knowledge on the part of the manufacturer's contact with the ground was only to be reached when the chassis was t loaded with at least 12 and were the wheels of the main landing gear to rotate. Due to the strong water film and the resulting aquaplaning the machine sat on though, but the wheels turned so slowly that the onboard computer of them went out, the machine is not located on the ground, and therefore prevented any braking. In addition, the machine did not begin until quite far behind in the landing zone of the web, so that even before the ground contact valuable braking distance was given away. When the system finally permitted the full braking ( wheel brakes, spoilers and thrust reversers ), the remaining length of the runway was no longer sufficient to bring the machine to a halt in time.

Consequences

The software of the fly-by -wire system of all models of the Airbus A320 family has been revised and the necessary Aufsetzdruck the chassis for the release of spoilers and thrust reversers from 12 t to 2 t now. Further, the activation of the spoilers and the thrust reverser is not coupled to the wheel rotation, the brake activation, however, still. Thus, it should be ensured that the aerodynamic and engine-side braking in any case works, even if the wheel does not turn fast enough.