Investigation Summary
The accident occurred as Flight 108 was conducting an ILS approach to Runway 24 at Düsseldorf Airport during a period of severe weather. Despite being warned by air traffic control that a preceding aircraft had just been struck by lightning, the crew continued their approach into a thunderstorm cell. At approximately 07:55 local time, a lightning strike hit the Metroliner, causing a catastrophic failure of the entire electrical system. This failure was likely exacerbated by damage to the electrical wiring, preventing the crew from restoring power. Without electrical power, the pilots lost their primary flight instruments, including the artificial horizons, and the cockpit was plunged into darkness. The aircraft was in an unstable configuration at the time of the strike, with the nose trimmed down and flaps set to the 'half' position. The crew suffered spatial disorientation and entered a series of uncontrolled descents and climbs. Ground witnesses observed the aircraft diving out of the clouds and pulling up sharply three times. During the final attempt to recover, the aerodynamic loads exceeded the aircraft's structural limits. The right wing separated, and the right engine propellers sliced through the forward fuselage, leading to a total mid-air disintegration.
Final Conclusions
The investigation concluded that the primary cause was the crew's decision to continue the flight into a known thunderstorm area where electrical discharges were expected. The resulting lightning strike caused a total loss of electrical power, which led to spatial disorientation and uncontrolled flight in Instrument Meteorological Conditions (IMC). The aircraft disintegrated due to structural overload during the crew's attempts to regain control. Contributing factors included the lack of an emergency power source for flight instruments, the crew's lack of preparation for a lightning strike, and the physical and mental impairment potentially caused by the strike itself. Additionally, the crew was briefly unable to communicate with each other after the strike because they were wearing headsets and the intercom system failed due to the power loss.
Photographic Evidence (1)
Video Analysis
Nürnberger Flugdienst 108 - [In-flight break-up 1) 2) 3)] — A detailed look at the loss of control and spatial disorientation following a lightning strike on NFD Flight 108, featuring aftermath footage and technical analysis.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
Hired by NFD in October 1987.
First Officer
Hired by NFD in July 1986.
Systems & Failure Modes
Electrical System
The total failure of the electrical system disabled all cockpit instruments, lighting, and the ability to operate the flaps and stabilizer trim.
Artificial Horizon
The aircraft was equipped with three artificial horizons, but all were dependent on the main electrical supply which failed after the lightning strike.
Flaps and Trim
These systems required electrical power for adjustment; their immobilization in a landing configuration contributed to the aircraft's instability during the high-speed descent.
Interesting Facts
- 01The aircraft was not equipped with an emergency power source for flight instruments, as it was not required by contemporary airworthiness regulations.
- 02The Metroliner III was at its full passenger capacity of 19 people.
- 03The investigation found that the trailing edge flaps failed due to overloading because they could not be retracted without electrical power.
- 04Air traffic control reported that a preceding aircraft experienced a lightning strike when it was approximately 6 miles from the runway.
Safety Actions & Advisories
Emergency Power Requirements
The accident highlighted the vulnerability of aircraft without independent emergency power sources for primary flight instruments, leading to reviews of certification requirements for regional aircraft.