Investigation Summary
The flight was the first leg of a scheduled service from Rotterdam to Hamburg via Eindhoven. During the pre-flight briefing, the crew was informed of thunderstorm activity in the area but no SIGMET (Significant Meteorological Information) had been issued. The aircraft departed at 17:04 CET and climbed into an unstable weather system where a warm front from the south met a cold low-pressure system from the west. At 17:09, the crew observed heavy weather on their radar and received clearance to deviate south to pass between two intense storm cells. At 17:12, the aircraft entered a localized tornado while flying through clouds. The sudden pressure drop associated with the vortex caused the altimeter to show a sharp, false increase in altitude. Simultaneously, the aircraft was subjected to violent vertical gusts. The airframe experienced G-loads of +6.8 g and -3.2 g, significantly higher than the +4 g limit for which the Fokker F28 was designed. These forces caused the starboard wing to bend upward and then sweep downward with such intensity that it detached from the fuselage. The crippled aircraft entered a spin and impacted a railway bridge near Moerdijk in an inverted position.
Final Conclusions
The investigation, conducted by the Raad voor de Luchtvaart (RvdL), concluded that the primary cause was the structural failure of the starboard wing due to extreme turbulence encountered within a tornado. The report (1983-01) noted that the weather reporting systems of the era were too slow to capture the rapidly evolving and localized nature of the tornado. The crew had followed standard procedures for weather avoidance based on the information available to them, but the intensity of the vortex was beyond the survivability of the airframe.
Photographic Evidence (1)
Video Analysis
That Time a Plane Crashed into a Tornado - NLM CityHopper 431 — A detailed breakdown of how a Fokker F28 regional jet flew into a tornado in the Netherlands, leading to a mid-air structural failure.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
Jozef Werner, aged 33. Had been with NLM CityHopper for nearly 11 years.
First Officer
Hendrik Schoorl, aged 28. Had been with the airline for three years.
Systems & Failure Modes
Weather Avoidance Radar
A rudimentary radar system used by the crew to identify precipitation cores; however, it could not detect the wind shear or the presence of a tornado vortex.
Starboard Wing Structure
The wing failed due to aeroelastic loads that exceeded the ultimate design strength of the Fokker F28-4000 airframe.
Interesting Facts
- 01The aircraft was named 'Eindhoven', which was also its intended destination.
- 02The G-loads recorded reached +6.8 g and -3.2 g, while the aircraft was only designed to withstand 4 g.
- 03A police officer on the ground photographed the tornado and the subsequent smoke from the crash site.
- 04A firefighter observing the accident from the ground suffered a fatal cardiac arrest.
- 05The altimeter showed a sudden altitude jump that was actually a result of the extreme low pressure inside the tornado vortex.
Safety Actions & Advisories
Weather Reporting Improvements
The accident highlighted the dangers of archaic weather reporting delays, leading to improvements in how rapidly changing severe weather data is disseminated to flight crews.
Tornado Encounter Probability Study
The Dutch Meteorological Office conducted a study following the crash, estimating that an encounter between an airliner and a tornado occurs approximately once every 300 million flight hours, emphasizing the rarity but necessity of considering such extreme convective phenomena in aviation safety.