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ASN Wikibase Occurrence # 246996
Last updated: 2 December 2021
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Date:22-APR-2010
Time:
Type:Schempp-Hirth Nimbus 4M
Owner/operator:
Registration:
MSN:
Fatalities:Fatalities: 0 / Occupants: 1
Other fatalities:0
Aircraft damage: Written off (damaged beyond repair)
Category:Accident
Location:nr Lenningen -   Germany
Phase: En route
Nature:Test
Departure airport:Haheneweide
Destination airport:Haheneweide
Investigating agency: BFU Germany
Narrative:
The flight was carried out in order to confirm in practice the proof of flutter stability of the aircraft type, which had already been provided by the manufacturer on the basis of calculations. This was to test the compliance with certification conditions for a major change to the aircraft type, the increase of the maximum take-off mass by 50 kg to 850 kg. After a flight duration of 1:12 hours, with changing altitudes and speeds, the complete tail unit broke off from the fuselage tube at an altitude of about 1600 m AMSL at a speed of about 160 km/h. The pilot was able to escape with the parachute.
The pilot was able to save himself with the parachute and remained uninjured; the aircraft crashed into a meadow.

Conclusions:
The properties and load-bearing capacity of the aircraft's fuselage structure were altered or weakened compared to the original design due to the various extraordinary loads in the aircraft's life cycle and the repairs carried out.
This led first to the detachment of the rib 11 from the structure and finally to the breakage of the entire tail unit.

Sources:

https://www.bfu-web.de/DE/Publikationen/Untersuchungsberichte/2010/Bericht_10_3X038_Nimbus4M_Lenningen.pdf?__blob=publicationFile

Accident investigation:
cover
  
Investigating agency: BFU Germany
Status: Investigation completed
Duration: 10 years and 9 months
Download report: Final report


Revision history:

Date/timeContributorUpdates
23-Jan-2021 15:08 harro Added

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