Airbus A320 Landing Crash in Okecie, Warsaw


On September 14th, 1993 an Airbus A320 was approaching Okecie, Warsaw. Due to untimely weather reports, it landed long, at high speed, on an angle, on a runway covered with standing water.

The braking system for the Airbus A320 used the following logic.

  • "On ground" = pressure on both main landing gear being greater than 12 tonnes.
  • "Reverse thrust allowed" = "On ground"
  • "Wheel brakes allowed" = "Wheel speed for at least one landing gear at greater than 72 knots" or ( "On ground" and "Radio altimeter reports less than 10 feet from ground" )

The left landing gear remained in the air for 9 seconds after the right landing gear touched, and both wheels were slow to reach a realistic approximation of ground speed.

The braking logic failed to deal with the combination of aquaplaning and most of the weight on one set of landing gear, and did not allow application of braking or reverse thrust until the aircraft was well along the runway.

After going off the end of the runway, the left wing struck an embankment, and one passenger and one pilot were killed in the crash.

Training:

Students attending "Safe Systems: Procure, Analyse, Develop, Operate", often think that the logic used in the braking system looks reasonable.

Warning:

Sometimes safety features can also introduce hazards.