Crossair pilots are faulted for sinking below minimum descent altitude, while carrier is accused of negligence

The captain of the Crossair BAE Systems Avro RJ100 that crashed on the approach to Zurich Kloten airport on 24 November 2001 "deliberately descended below the minimum descent altitude [MDA]" without being able to see the runway or approach lights, says the Swiss accident investigation report.

The report catalogues previous breaches of standard operating procedure by the same captain and says that fatigue was a factor in the accident, which killed 24 of the 33 people on board, including both pilots.

The co-pilot, who was the pilot not flying, called the MDA on reaching it but is criticised in the report as having "made no attempt to prevent the continuation of descent below the MDA".

The captain was assessed as fatigued, because in addition to his Crossair duty he had also been flying as an instructor at the Horizon Swiss Flight Academy on the day of the accident and the day before it, lengthening both duty days to between 13h and 15h with little more than 10h rest between them.

The report does not allocate all the blame to the crew, saying that "over a long period of time, the responsible persons at the airline did not make correct assessments of the commander's flying performance. Where weaknesses were perceptible, they did not take appropriate measures."

The report notes that the weather conditions on the approach were not good enough to achieve a safe landing from the MDA, but the crew knew only the weather for the airport. Finally, there was no minimum safe altitude warning system (MSAWS) on Zurich radar, which could have alerted the controller to the fact that the aircraft was descending below the proper descent profile. MSAWS has now been installed. Crossair, now Swiss International Air Lines, has supplied a long list of pilot training quality- control measures that have been put in place as a result of the report's recommendations.

No mention has been made in the report of why Kloten air traffic control asked the crew to carry out a non-precision approach to runway 28 when an instrument landing system approach to runway 14 was available. When the crew had begun their descent from cruise, 14 was still the active runway. The approach path to 14 overflies southern Germany, which enforces an overflight curfew from 21:00 because of the noise of aircraft approaching Zurich. The aircraft crashed at 21:06:36.

Source: Flight International