What happened
On May 15, 1986, a Malév-Airlines Tupolev TU-134, registration HA-LBH, was performing a scheduled passenger flight from Budapest to Zurich. During the approach to runway 14, the crew utilized a VOR/DME procedure, which was being used as a substitute because the primary ILS for runway 14 was out of service for upgrades.
As the aircraft descended, the crew believed they were aligned with runway 14. However, due to the specific geometry of the VOR/DME approach, the aircraft was actually tracking toward the threshold of runway 16. Upon visual contact with the ground, the crew realized the error. The captain took control from the co-pilot and attempted a late correction to intercept the correct runway. This maneuver resulted in an unstable approach, and the aircraft touched down approximately 500 meters past the runway 14 threshold. During the correction, the left main landing gear struck two runway lights, causing damage to the aircraft's braking system.
The investigation
The investigation examined the technical aspects of the VOR/DME approach and the crew's decision-making. It was established that the VOR/DME 14 approach procedure was inherently critical because its centerline did not align with the runway axis, requiring a 10-degree left turn during the final stages. Furthermore, the approach track passed directly over the threshold of runway 16, which created a high risk of runway confusion.
Investigators also reviewed the flight data and cockpit voice recordings. They found that while the flight was within technical tolerances, the crew failed to verify the assigned runway early enough and did not initiate a missed approach once the error was identified.
Findings
- The primary cause of the incident was the approach to the wrong runway due to a flawed VOR/DME procedure that suggested runway 16 was the intended target.
- The approach procedure lacked any specific warnings regarding the high risk of runway confusion.
- The crew identified the error too late to perform a stabilized approach.
- The pilot in command failed to execute a go-around after realizing the aircraft was tracking toward the incorrect runway.
- The final phase of the landing was unstable due to the late corrective maneuver.
Safety action
The investigation noted that the VOR/DME 14 procedure had been suspended as of May 16, 1986. The commission recommended that the airport evaluate the permanent removal of this specific VOR/DME procedure in favor of more reliable precision approaches, such as the ILS for runway 16, to prioritize safety over noise or capacity considerations.