Introduction
On 25 January 2001 at 21:24 local time, a Piper PA-34-220T (manufactured by New Piper) crashed into hilly terrain while on approach to Augsburg Airport. The aircraft, registered in the United States, was returning from Biggin Hill, England, on an Instrument Flight Rules flight. The planned approach was an ILS to runway 25. The accident resulted in the death of the pilot and three passengers; one passenger was seriously injured. The aircraft was destroyed.
Flight History
The flight departed Biggin Hill at 18:30. Radar data show the aircraft approaching Augsburg from the north at an altitude of 3,300 ft descending, heading 170°. Shortly thereafter, the heading changed to approximately 250°, placing the aircraft 0.72 nm right of the localizer centerline at 7.3 DME. The pilot was vectored by Munich Center. At 21:14, the aircraft contacted Munich Center and was identified. Radar vectors were given, and the pilot was cleared for the approach. At 21:21:57, the controller asked if the pilot was established on the localizer; the pilot replied, "Just the localizer." The controller then instructed the pilot to contact Augsburg Tower. The tower provided wind, QNH, and landing clearance. Immediately after, the aircraft initiated a descent from 3,300 ft at 4.2 DME. The descent did not follow the glideslope, and the lateral deviation persisted. Radar tracking ended at 2.9 DME at 2,200 ft. The aircraft struck terrain before the runway threshold.
Injuries and Damage
One pilot and three passengers were killed. One passenger sustained serious injuries. The aircraft was destroyed beyond repair.
Investigation Findings
The investigation by the German Federal Bureau of Aircraft Accident Investigation (BFU) identified multiple factors:
- The GPS was still active as the signal source for the horizontal situation indicator (HSI), which suppressed the glideslope display.
- A radar-visible lateral deviation from the approach centerline existed but was not detected by the crew nor communicated by air traffic control.
- There was a lack of coordination between the involved ATC units, and the radar data display system at Augsburg Airport was not utilized.
- During the night final approach, neither ground visibility nor visual contact with the airport was established before reaching the minimum descent altitude (MDA).
- The descent continued below the applicable MDA (2,140 ft, with glideslope inoperative) without visual reference.
Contributing factors included:
- Deficient design of the GPS/NAV switch illumination and arrangement, which hindered monitoring and made cross-checking impossible for a second pilot.
- The absence of an automatic direction finder (ADF) and the lack of use of an additional ILS display available in the aircraft.
- The Munich Center team misjudged the situation and did not react appropriately.
- The radar data display system was not exempted from its restricted use in special situations (such as loss of orientation) per local coordination procedures.
- The pilot, after a long duty day and high workload, failed to adapt to the ILS approach without glideslope information or recognized the lack of glideslope indications too late.
Probable Cause
The accident was attributed to the following causes: the GPS remained as the signal source for the HSI, suppressing glideslope information; a radar-visible lateral deviation was not detected or communicated; lack of ATC coordination and non-use of the radar display at Augsburg; no visual contact during the night approach; and descent below the MDA without visual reference. Contributing causes included poor switch design, missing ADF, lack of use of additional ILS, inadequate crew and ATC responses, and pilot fatigue.