19970515010809A

Accident · Substantial damage

FAA accident report · Bell 47G-3B · Snohomish, WA · May 15, 1997

Date: May 15, 1997 · 16:10 local
Place: Snohomish, WA
Phase of flight: Go Round (Aborted VFR)
Operating rules: General operating rules (Part 91)
Damage: Substantial damage
Aircraft: N8491E
NTSB investigation: NTSBSEA97LA112
Reported as: Bell 47G3B
Reported engine: Lycoming TVO435B1A
Fatal injuries: 0
Pilot’s flight hours: 775 total36 in this make and model60 in the last 90 days

N8491ERegistration cancelled Jan 26, 2018 · Bell 47G-3BS/N 2712 · Built 1961 Airframe modelBell 47G-3B Engine modelLycoming TVO-435-GIATurbo-prop

From the FAA’s Accident/Incident Data System (AIDS), through its Aviation Safety Information Portal, as reported. The NTSB investigates accidents separately, and its record of an accident is the fuller one. The aircraft is matched to the registry by N-number and event date, checked against the reported make and model; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

What happened

The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.

(.4) The pilot was in a commercial helicopter pilot upgrade training program. He was not yet rated for helicopters, but did hold an instructor's endorsement granting helicopter solo privileges. At the time of the accident, he was aborting a practice landing in wind conditions which were conducive to an unanticipated right yaw (also known as loss of tail rotor effectiveness, or lte) event. As he completed a turn to downwind, the helicopter made an uncommanded right turn. Despite the application of left pedal and forward cyclic by the pilot, the helicopter 'continued to rotate violently until impact on the left side.' FAA inspectors, who examined the helicopter at the accident site, reported that they found no evidence of a mechanical malfunction; they stated that the tail rotor system was intact.

As the FAA filed it

(.4) THE PILOT WAS IN A COMMERCIAL HELICOPTER PILOT UPGRADE TRAINING PROGRAM. HE WAS NOT YET RATED FOR HELICOPTERS, BUT DID HOLD AN INSTRUCTOR'S ENDORSEMENT GRANTING HELICOPTER SOLO PRIVILEGES. AT THE TIME OF THE ACCIDENT, HE WAS ABORTING A PRACTICE LANDING IN WIND CONDITIONS WHICH WERE CONDUCIVE TO AN UNANTICIPATED RIGHT YAW (ALSO KNOWN AS LOSS OF TAIL ROTOR EFFECTIVENESS, OR LTE) EVENT. AS HE COMPLETED A TURN TO DOWNWIND, THE HELICOPTER MADE AN UNCOMMANDED RIGHT TURN. DESPITE THE APPLICATION OF LEFT PEDAL AND FORWARD CYCLIC BY THE PILOT, THE HELICOPTER 'CONTINUED TO ROTATE VIOLENTLY UNTIL IMPACT ON THE LEFT SIDE.' FAA INSPECTORS, WHO EXAMINED THE HELICOPTER AT THE ACCIDENT SITE, REPORTED THAT THEY FOUND NO EVIDENCE OF A MECHANICAL MALFUNCTION; THEY STATED THAT THE TAIL ROTOR SYSTEM WAS INTACT.

NTSB investigation

The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.

NTSB SEA97LA112Accident · Minor injuriesLimited investigationFinal reportSnohomish, WAthe pilot's encounter with of a loss of tail rotor effectiveness (LTE) situation, and his subsequent inadequate remedial action. Related factors included: wind conditions that were conducive to an unanticipated right yaw event, and the pilot's limited…May 15, 1997 · Substantial damage