NLM CityHopper Flight 431

NLM CityHopper Flight 431 refers to a Fokker F-28-4000, registration PH-CHI, that was due to operate an international scheduled Rotterdam–Eindhoven–Hamburg passenger service. On 6 October 1981, the aircraft encountered severe weather on the first leg, minutes after taking off from Rotterdam Airport, and crashed 15 miles (24 km) south-southeast of Rotterdam. All 17 occupants of the aircraft – 13 passengers and crew of 4 – perished in the accident.[1]^:183[2]

NLM CityHopper Flight 431

The crash site of NLM Flight 431
Accident
Date	6 October 1981
Summary	Structural failure in severe turbulence[1]^:183
Site	Moerdijk, near Rotterdam Airport, Netherlands 51°42′N 4°31′E
Aircraft
Aircraft type	Fokker F-28-4000
Aircraft name	Eindhoven
Operator	NLM CityHopper
Registration	PH-CHI
Flight origin	Rotterdam Airport
Stopover	Eindhoven Airport
Destination	Hamburg Airport
Occupants	17
Passengers	13
Crew	4
Fatalities	17
Survivors	0

Aircraft and crew

PH-CHI, the aircraft involved in the accident, is seen here in May 1981

The aircraft involved in the accident was a Fokker F28-4000, registration PH-CHI, that was built in 1979 with c/n 11141. At the time of the accident the airframe had accumulated 4,485 flight hours and 5,997 cycles.[2]

The captain was 33-year-old Jozef Werner, who had been with NLM CityHopper for nearly 11 years. He had 4,900 flight hours, including 309 hours on the Fokker F28. The first officer was 28-year-old Hendrik Schoorl, who had been with the airline for three years and had 2,971 flight hours, with 2,688 of them on the Fokker F28.[3]

Description of the accident

During the weather briefing 44 minutes before takeoff, the crew was apprised to an area of strong thunderstorms with 3/8 (37.5%) sky coverage of cumulonimbus at a base of 1,200 feet (370 m), south-southwest winds 15 to 25 knots (28 to 46 km/h; 17 to 29 mph) strong, and 5 kilometres (3.1 mi) visibility at Rotterdam Airport (IATA: RTM).[2] The aircraft took off at 5:04 p.m. CET (UTC +1) from RTM.[2] The crew noted heavy rain in thunderstorms on the airplane's weather avoidance radar at 5:09 p.m., receiving clearance to avoid the area.[2] At 5:12 p.m. the aircraft entered a tornado while flying through clouds.[2] The weather system the aircraft entered into was apparently the same "tornado-like" system that Zeeland locals described as being responsible for considerable property damage.[4] Meteorologically, these vortices are indeed tornadoes, and the disintegrating airliner was seen exiting cloud cover. A police officer first photographed the tornado, then smoke from the burning plane a few minutes later. An investigation concluded that a sharp increase in altitude registered on the altimeter was not a change in altitude, rather a pressure drop associated with the tornado.[5][6]

Stresses experienced by the airframe owing to severe turbulence (due to a "downburst" or "mircroburst" of a few seconds)[7] resulted in loads of +6.8 g and −3.2 g causing the starboard wing to detach.[2][8] The Fellowship was designed for a maximum G-load of up to 4 g.[7] The aircraft spun down into the ground from 3,000 ft (910 m), crashing some 400 m (1,300 ft) from a Shell chemical plant on the southeastern outskirts of Moerdijk.[4] All 17 occupants of the aircraft perished in the accident.[2] While observing the unfolding incident from the ground, a firefighter suffered a fatal cardiac arrest.[3]

See also

• List of accidents and incidents involving commercial aircraft

References

1. • Learmount, David (23 January 1982). "Commercial flight safety: 1981 reviewed". Flight International. 121 (3794): 183. ISSN 0015-3710. Archived from the original on 22 January 2015. 
   • "Commercial flight safety: 1981 reviewed". Flight International: 184. Archived from the original on 22 January 2015. 
   • "Commercial flight safety: 1981 reviewed". Flight International: 185. Archived from the original on 22 January 2015. 
   • "Commercial flight safety: 1981 reviewed". Flight International: 186. Archived from the original on 22 January 2015. 
2. Accident description at the Aviation Safety Network. Retrieved on 14 November 2011.
3. van Tuyl, Johan. "F.28 Fellowship verongelukt bij Moerdijk" [F.28 Fellowship crash at Moerdijk]. AVIACRASH.NL (in Dutch). Archived from the original on 19 May 2006. Retrieved 27 October 2018.
4. "F.28 crashes in bad weather". Flight International: 1127. 17 October 1981. Archived from the original on 30 July 2013.
5. Grazulis, Thomas P. (2001). The Tornado: Nature's Ultimate Windstorm. Norman, OK: University of Oklahoma Press. pp. 260–1. ISBN 0-8061-3258-2.
6. Roach, W.T.; J. Findlater (February 1983). "An Aircraft Encounter with a Tornado". Meteorological Magazine. London: Meteorological Office. 112 (1327): 29–49.
7. "6 oktober 1981: Vliegtuigcrash Moerdijk" [October 6, 1981: Moerdijk plane crash]. ww5.zero-meridean.nl (in Dutch). Archived from the original on 14 January 2008. Retrieved 2 February 2021.
8. "F.28 wing loss followed severe turbulence". Flight International: 1124. 17 October 1981. Archived from the original on 30 July 2013.

External links

• Accident details at planecrashinfo.com