Background
On 14 November 1990, Alitalia Flight 404, a scheduled commercial flight, operated a DC-9-32 with registration I-ATJA. The aircraft departed from Linate Airport (LIN) runway 36R at 1836 hours, bound for Zurich Airport (ZRH). The pilot-in-command (PIC) served as the assisting pilot and handled radio communications, while the first officer (FO) was the handling pilot.
Flight Progress
After an uneventful climb via the CANNE departure to flight level (FL) 200, the crew listened to the Zurich VOLMET and learned that the surface wind was 240/08 kt. The crew discussed a possible landing on runway 28, although the ATIS indicated runway 14. During the descent, the crew calculated a QFE of 970 hPa from the QNH of 1019 hPa. They discussed approach procedures for runway 14, and the FO mentioned the outer marker height for runway 16.
Approach and Descent
Air traffic control instructed the crew to fly an ILS approach to runway 14. At 1900.01, the FO called for a "CAT JJ approach," which the PIC agreed to. As the aircraft descended, the PIC noted they were being brought in high. At 1906.20, ATC cleared the flight to 4000 ft QNH and heading 110; the PIC incorrectly read back heading 120, causing confusion. The aircraft passed through the localiser and descended through 4000 ft, approximately 1200 ft below the glide path. The altitude alert sounded, but the PIC cancelled it by setting the go-around altitude. Later, the FO called "GO AROUND," but the PIC countered with "No, no, no, no ... catch the glide." The crew then attempted to reduce the sink rate.
Collision
At 1911.18 hours, the aircraft struck the north slope of the Stadlerberg at an altitude of 1660 ft QNH. All 46 occupants were killed.
Probable Cause
The official investigation concluded that the accident was the consequence of the combination of the following factors:
- False indication of VHF NAV unit n°1 in the cockpit
- Probable altimeter misreading by the PIC
- No GPWS warning in the cockpit
- Pilots not aware of the possibility of incorrect indications in the NAV equipment in use (without flag-alarm)
- Inadequate failure analysis by the pilots
- Non-compliance by the pilots with basic procedural instructions during the approach
- Unsuitable cooperation between the pilots during the approach
- COPI's initiated go-around procedure aborted by the PIC
- The Approach Controller not observing the leaving of the cleared altitude of 4000 ft QNH before the FAP