DAVID LEARMOUNT / LONDON
A lack of evidence of any aircraft or navigation aid malfuction has led German accident investigators to focus on human factors in most of their interim recommendations relating to last year's Crossair BAE Systems Avro RJ100 crash in Germany. The aircraft crashed into a forest on a poor-weather night approach to runway 28 at Zurich airport, Switzerland, on 24 November 2001 (Flight International 4-10 December 2001).
The recommendations passed by the German accident investigation agency (BFU) to the Swiss federal aviation authority are effectively aimed at the recently restructured airline Swiss, of which the former Crossair is now part. The BFU said the airline's crew-pairing practices should be better defined. Swiss says in this case it believes that the BFU refers to the fact that, although the captain was experienced, he had recently been the young co-pilot's instructor, possibly making the co-pilot less likely to challenge the captain's actions.
Pilot selection and training, says the BFU, should take account of gaps in each pilot's performance or knowledge, but the agency was not specific about why the recommendation was made. The RJ100 accident, however, is one of two fatal Crossair crashes being investigated, the other being the 10 January 2000 loss of a Saab 340 on departure from Zurich, which is believed to have resulted from pilot disorientation leading to loss of control.
The BFU says all completed studies indicate there was no malfunction of the aircraft or the ground-based navigation equipment. Other recommendations include:
airlines should be cautious about changing the manufacturer's recommendations for procedures in non-precision approaches; new-generation aircraft should be fitted with enhanced ground proximity warning systems (EGPWS). The Crossair aircraft had standard GPWS. checks should be made to ensure that weather information available to Zurich air traffic control for the relatively little-used runway 28 approach is good enough; air traffic control should have a minimum safe altitude warning system for the runway 28 approach as it has for 14 and 16; the Swiss aviation authority should ensure that Jeppesen approach charts show all flight obstacles on approaches.The crew had originally been cleared for an instrument landing system (ILS) to runway 14, but at 22:00, a recently approved noise abatement procedure came into force that meant they had to change to a VOR/distance measuring equipment approach to 28 instead. The BFU has made no recommendations so far about the effect of noise abatement rules on safety, but a recommendation was made soon after the accident to install an ILS for runway 28, and this has been approved.
Source: Flight International
