Investigation Summary
The flight was originally prepared for an ILS approach to runway 14, but due to a 21-minute delay, it arrived after the 22:00 CET curfew that prohibited approaches over southern Germany. Zurich ATC redirected the flight to runway 28, which only offered a non-precision VOR/DME approach. This required the crew to manually monitor their altitude against distance (DME) and level off at a Minimum Descent Altitude (MDA) of 2,400 feet until the runway was in sight. During the descent, Captain Lutz maintained a steep glide path and failed to properly monitor his distance from the airport. Despite not having the runway in sight, he continued the descent below the MDA. The First Officer, who was significantly less experienced, failed to challenge the captain's decision to descend into the darkness. The aircraft was actually 7.4 kilometers from the runway when the captain's comments indicated he believed he was near the 4.1 kilometer (2.2 nautical mile) mark, a distance where a preceding aircraft had reported seeing the runway. The Ground Proximity Warning System (GPWS) eventually triggered a 'minimums' warning based on the radio altimeter, but the captain's subsequent call for a go-around came too late to prevent the aircraft from striking the treetops on a ridge near Bassersdorf. Investigators also noted that the captain's ability to analyze complex processes was adversely affected by fatigue.
Final Conclusions
The Swiss Aircraft Accident Investigation Bureau (AAIB) concluded the primary cause was the commander's deliberate descent below the MDA without visual contact. The investigation highlighted severe systemic failures within Crossair's pilot monitoring programs. Captain Lutz had a documented history of poor performance, including failing MD-83 type ratings due to navigation difficulties, accidentally retracting landing gear on the ground in 1991, and a near-collision with Lake Lugano. Despite these red flags, Crossair kept him in a passenger-carrying role due to pilot shortages. Contributing factors included the captain's fatigue, which impaired his decision-making; the lack of a Minimum Safe Altitude Warning (MSAW) system for runway 28; inadequate visibility reporting for that specific approach sector; and the use of an approach chart that did not clearly mark the hills in the flight path.
Photographic Evidence (1)
Video Analysis
Crossair Flight 3597 Zurich Airport Crash Investigation — Documentary investigation into the CFIT accident of Crossair 3597, examining pilot history and the impact of noise abatement laws on flight safety.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
Hans Ulrich Lutz. Had a history of navigational errors and failed certifications. 19,300 of his total hours were as Pilot in Command.
First Officer
Stefan Löhrer. Hired recently out of flight school.
Systems & Failure Modes
VOR/DME Approach
A non-precision approach providing lateral guidance via a VHF Omnidirectional Range station and distance via Distance Measuring Equipment, but no vertical glide slope.
GPWS
The Ground Proximity Warning System provided a 'minimums' alert based on the radio altimeter, but the warning occurred too late for the engines to spool up and clear the terrain.
MSAW
Minimum Safe Altitude Warning; a ground-based system that was notably absent for runway 28, which would have alerted controllers to the aircraft's low altitude.
Interesting Facts
- 01The crash killed 24 people, including American singer Melanie Thornton and two members of the Eurodance group Passion Fruit.
- 02The 33 occupants consisted of 28 passengers and 5 crew members.
- 03The captain had nearly 20,000 flight hours but had recently struggled with modern computerized navigation systems.
- 04The BFU investigation found the captain's ability to analyze complex processes was adversely affected by fatigue.
- 05Runway 28 at Zurich lacked an Instrument Landing System (ILS) and a Minimum Safe Altitude Warning (MSAW) system at the time.
- 06The hills the aircraft struck were not explicitly marked on the Jeppesen approach charts used by the crew.
- 07The captain had been relieved of flight instructor duties in 1991 after a ground accident involving a Saab 340 where he retracted the gear while parked on the apron.
Safety Actions & Advisories
MSAW Implementation
Zurich Airport installed Minimum Safe Altitude Warning systems for all approach paths, including runway 28.
Pilot Performance Monitoring
Recommendations were made to Swiss aviation authorities to ensure airlines strictly monitor and act upon repeated pilot training failures.