Done by: Ang Ching Yang (1303571B)
1.1 About the assignment
In international air transportation, airline flight operations play a critical part in ensuring passengers and cargo arrive at their destinations safely and on time. Having seen Crossair flight 3597’s crash, the objective of this assignment is to analyse the factual information, causes of the crash and thus learn valuable lessons from the errors committed that led to the crash.
2. Facts of Crossair flight 3597
2.1 About Flight 3597
Crossair Flight 3597 was a scheduled flight from Berlin-Tegel, Germany to Zurich in Switzerland on 24 November 2001. 28 passengers, 3 flight attendants and 2 flight crew were on board. The commander was the Pilot Flying (PF) and the first officer is the Non-Pilot Flying (NPF) or the support role of monitoring and handling radio communications.
2.2 Approach type
Events relevant to the accident started when Crossair flight 3597 received clearance to commence an approach to runway 28, Zurich Airport, at 20:58:50 UTC. At Zurich Airport, runway 28 was not equipped with an Instrument Landing System (ILS); the pilots must fly a non-precision or VOR/DME approach. The approach sector was not fitted with a minimum safe altitude warning system (MSAW) which triggers an alarm if a minimum safe altitude is violated. The range of the hills which the aircraft crashed into was missing on the approach chart used by the flight crew.
The weather conditions, particularly runway visual range, was measured by the airport from a station distant from runway 28, thus did not accurately reflect the actual visibility. The flight ahead of Flight 3597 advised that the weather condition was near minimums- they were not visual with the runway until the very last minute, at about 2.2 nautical miles. The valid visual minimums were thus inappropriate to use standard VOR/DME approach 28. Despite this, the pilots continued with their approach.
2.3 Descent through MDA
The pilots reached the minimum descent altitude (MDA) of 2,390 feet AMSL at 21:06:10. At this point, the captain advised the first officer that he had the ground contact and continued to descend below the MDA, which the first officer did not prevent. There was no indication that either pilot had the runway or approach lighting in sight, which were the requirements for descent below the MDA. According to the cockpit voice recorder (CVR), both pilots, especially the captain, were trying to spot the runway and keep the ground in sight throughout the rest of the sequence.
2.4 Lack of warnings
Despite being equipped with a basic Ground Proximity Warning System (GPWS), there were no urgent "terrain, terrain!" and "pull up!" warnings, as the aircraft was being flown in a profile conducive with landing, and therefore was outside of the flight envelope required for the warnings to be sounded. As the VOR/DME approach is done under the aircraft’s own navigation, no radar vectors were given by ATC.