The pilot reported that he was flying the Funk B85C about 700 feet above the ground in cruise flight when he felt the control stick “pop” and the nose of the airplane pitch down.
He pulled back the throttle and turned off the magnetos. The passenger adjusted the elevator trim, however, the pitch attitude did not change.
The pilot then entered a side slip, which brought the nose up to level. He straightened the nose of the airplane just prior to it hitting terrain near Leonard, Oklahoma.
The plane subsequently flipped inverted, resulting in substantial damage to the wings and fuselage, but no injuries to the pilot or passenger.
A post-accident examination revealed the UP elevator turnbuckle became detached at the elevator torque tube. The turnbuckle was not safety wired. New cables were installed in the airplane in 2007 and the turnbuckle most likely loosened over time.
Probable cause: The improper installation of the UP elevator cable turnbuckle, which became disconnected during the flight.
NTSB Identification: CEN15CA166
This March 2015 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
I have seen airplanes especially those of vintage years go for years without a true annual inspection by a truly qualified mechanic/IA. I would also suspect that the owner replaced the cables and failed to finish the job of safeting them.
I’m thinking that just before the turnbuckle ran out of threads to grab, there would have been substantial “slack” in the cable that might have been noticed by pilots who regularly flew that airplane.
Good point. A ground controls check should have indicated a dead band where the stick would move but the control did not. This would be apparent when the elevator was in the full nose-down position and you moved the stick towards nose up. There should be immediate movement but many pilots, especially low time ones, might not be aware of this important aspect of the controls check prior to flight. That comes down to the quality of the instruction they have received. Bottom line is most pilots do not understand the inner mechanics of the aircraft and would not realize the significance of such a deadband unless specifically trained to look for such.
Considering this was a certified production aircraft and therefore required an IA to sign off on Annuals I think someone’s license would be in jeopardy. The continuity of the control system and its proper rigging would seem to be a normal item of such an inspection. A simple visual inspection of the control system would show a turnbuckle that was not safetied which was a definite airworthiness item.
If the unsafetied turnbuckle was installed with new cables in 2007, and it’s now 2017, who inspected this aircraft over the last ten annual inspections ? This oversight is outrageous !!
They accident happened in 2015, but doesn’t make your point any less valid. That’s 7-8 annuals where it was overlooked.
Wow. Not sure I would have thought about that slide slip. Outstanding.
Agreed! That was an amazing recovery from a very bad situation!
This low time, 19 year old pilot was IMPRESSIVE!
According to the NTSB Factual Report his flight hours were:
140.9 hours (Total, all aircraft), 25.1 hours (Total, this make and model), 108.4 hours (Pilot In Command, all aircraft), 76.1 hours (Last 90 days, all aircraft), 17.6 hours (Last 30 days, all aircraft), 1.8 hours (Last 24 hours, all aircraft)
I agree at 140 hours I most likely wouldn’t have handled that situation that well. I would have maybe though of the trim, but the sideslip to level the nose is brilliant!