ASN logo
ASN Wikibase Occurrence # 40838
Last updated: 25 November 2021
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information. If you feel this information is incomplete or incorrect, you can submit corrected information.

Type:Silhouette image of generic FH11 model; specific model in this crash may look slightly different
Fairchild Hiller FH-1100
Owner/operator:Horizon Helicopters Inc
Registration: N8171U
MSN: 254
Fatalities:Fatalities: 1 / Occupants: 1
Other fatalities:0
Aircraft damage: Written off (damaged beyond repair)
Location:Dewitt, MI -   United States of America
Phase: En route
Departure airport:Grand Ledge, MI
Destination airport:St. Johns, MI
Investigating agency: NTSB
A Hiller FH-1100 was destroyed on impact with terrain following the separation of a tail rotor blade in cruise flight. The tail rotor blade 'B' was separated 1/4 span from its root and was discovered 700 feet south of the main wreckage. Blade 'A' was found 850 feet south of the main wreckage. The tail rotor blades were overhauled and later removed for blade delamination on July 14, 1986. The inside surfaces of the blade 'A's' skin showed longitudinal streak patterns of debris. The skin trailing edge closure bond contained an adhesive that was bright purple in color. During 1967-1982 tail rotor blades were bonded with FM1000; a cream or off white colored adhesive. Since 1982, FM1000 bonded the skin and doubler and FM73, which is orange brown in color, between the root fitting and doubler. The rivet holes in the skin were worn on the skin surfaces under the upset heads of the rivets. No wear was visible under the manufactured heads. The rivet holes were not round and appeared to have two overlapping diameters consistent with double drilling. The Hiller FH1100 Overhaul Manual Tail Rotor Assembly, Repair - Tail Rotor Blade Assembly, states, '...Replacement of skin, doubler or rib ... is not permitted.' The Hiller FH1100 Inspection Guide described the inspection of the tail rotor blades during preflight, 100-hour inspection and 300-hour inspection. CAUSE: The rotor failure/malfunction due to debonding of the tail rotor blade. Also causal was the inadequate maintenance inspection of the aircraft by the company and the improper maintenance procedure by other maintenance personnel.



Revision history:

24-Oct-2008 10:30 ASN archive Added
21-Dec-2016 19:23 ASN Update Bot Updated [Time, Damage, Category, Investigating agency]

Corrections or additions? ... Edit this accident description