Engine Power Loss Leads to Emergency Landing of Fokker 70 at Munich

Casualties unknown • Verkehrsflughafen München, DE

A Fokker 70-bound for Munich from Vienna was forced to perform an emergency landing in a snow-covered field after ice-related failures caused significant power loss in both engines.

What happened

On January 5, 2004, at 07:27, an Austrian-registered Fokker 70 departed Vienna for a scheduled flight to Munich. The flight proceeded normally until the aircraft entered the approach phase for Munich Airport. During the descent, the crew activated anti-ice systems as icing conditions were encountered.

While descending through flight level 90, the crew noted high vibrations in the right engine. Shortly thereafter, the aircraft experienced a significant drop in engine pressure ratio (EPR) in the left engine, followed by a similar decline in the right engine. Along with the loss of thrust, the crew reported loud, unusual noises and vibrations throughout the cabin. Due to the severe engine issues, the pilot-in-command declared an emergency and requested an immediate landing.

Unable to maintain the glide path due to the loss of thrust, the aircraft performed an emergency landing approximately 2.5 NM from the runway threshold. The aircraft struck a snow-covered field, sliding for 220 meters before coming to a halt on its fuselage. The aircraft sustained heavy damage, and while three persons sustained slight injuries, all occupants were able to evacuate the aircraft without assistance.

The investigation

The BFU investigation focused on the mechanical failure of the engines and the degradation of thrust. Investigators examined the engine components, specifically the low-pressure compressor rotors and the ice protection panels. The investigation also reviewed flight data recorder (FDR) and cockpit voice recorder (CVX) information, as well as meteorological data and maintenance records regarding the adhesive used for the ice protection panels.

Findings

  • Ice had formed on the low-pressure compressor rotors of both engines following a period of moderate icing conditions at low engine power.
  • The adhesion of the ice protection panels failed in both engines due to stresses caused by engine vibrations and the impact of ice shedding from the compressor rotors.
  • The detached ice protection panels became lodged in front of the low-pressure compressor guide vanes, disrupting the airflow and causing a significant reduction in thrust.
  • The loss of thrust was not immediately flagged by cockpit warnings, which prevented the crew from identifying the issue until a power demand was made during the descent.
  • The terrain chosen for the emergency landing was unsuitable for a commercial aircraft due to its physical characteristics.

Probable cause

The primary cause of the accident was the failure of the ice protection panels to remain attached to the engines, which led to airflow disruption and a critical loss of thrust. This failure was triggered by ice accumulation on the compressor rotors and subsequent vibrations.

Frequently asked questions

What happened in the 2004-01-05 Fokker Aircraft B.V. F28 Mk0070 accident near Verkehrsflughafen München, DE?

A Fokker 70-bound for Munich from Vienna was forced to perform an emergency landing in a snow-covered field after ice-related failures caused significant power loss in both engines.

What aircraft was involved and where did it happen?

The accident on 2004-01-05 involved a Fokker Aircraft B.V. F28 Mk0070, at Verkehrsflughafen München, DE.

What was the probable cause of the accident?

The primary cause of the accident was the failure of the ice protection panels to remain attached to the engines, which led to airflow disruption and a critical loss of thrust. This failure was triggered by ice accumulation on the compressor rotors and subsequent vibrations.

Loading the flight search…