Crossair's fatal crash during final approach to Zurich Kloten airport on 24 November came just a month after a new noise abatement procedure began forcing pilots to use a non-precision approach to the airport at night.
Instrument landing system (ILS) precision approaches were available at Kloten on the night of the crash, when the visibility was poor in light snow, but only on runways affected by the new noise-abatement rules.
Crossair says that its BAE Systems Avro RJ100 (HB-IXM) was "too low" for that stage of its approach, though the airline does not yet know why. Inbound to Zurich from Berlin, it hit the ground in a wooded area 2nm (3km) from the threshold of runway 28. The airline confirms that 21 of the 28 passengers and three out of the crew of five died.
The pilots originally briefed for an ILS approach to runway 14, but were told the approach would be a VOR/DME approach to runway 28. This entails flying on range and bearing information from a navigation beacon on the airfield, but it does not give the glidepath guidance that an ILS provides.
The radio altimeter warned the crew when they reached 500ft (150m) and then 300ft above ground level (AGL), but the crew had still not reported the airfield in sight. Just after that, say investigators, the captain - who was the pilot flying - told the co-pilot he was going-around (abandoning the approach), but it was too late and the aircraft hit tree tops.
The new noise abatement procedures, agreed between Germany and Switzerland, rule out all except essential use of the two main ILS runways (14 and 16) after 22:00 because an approach from the north means the aircraft flies low over southern Germany. The accident occurred at 22:06. Switzerland's aviation authority says that Zurich has been planning to install an ILS for runway 28, but the authority says that it would be more than a year before it could be operational.
Source: Flight International
