20110623012719A

Accident · Substantial damage

FAA accident report · Hiller UH-12E · Hanford, CA · June 23, 2011

Date: June 23, 2011 · 04:30 local
Place: Hanford, CA
Airport: N/A
Phase of flight: Hover/Holding
Operating rules: Agricultural (Part 137)
Operator: MEZG
Damage: Substantial damage
Aircraft: N99579
NTSB investigation: NTSBWPR11LA282
Reported as: Hiller UH-12E
People aboard: 1
Fatal injuries: 0
Other injuries: 0

N99579Registered now · Hiller OH-23GS/N 64-15224 Airframe modelHiller OH-23G

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.

At 0430 the aircraft was being service and refueling when the pilot noticed excess play and oil leaking from the tail rotor drive coupling while the aircraft was at idle. As the pilot moved the aicraft from the service truck to the ground for further maintenance the aircraft lost power to the tail rotor causing the aircraft to rotate 4 to 5 times before impacting the ground.

As the FAA filed it

AT 0430 THE AIRCRAFT WAS BEING SERVICE AND REFUELING WHEN THE PILOT NOTICED EXCESS PLAY AND OIL LEAKING FROM THE TAIL ROTOR DRIVE COUPLING WHILE THE AIRCRAFT WAS AT IDLE. AS THE PILOT MOVED THE AICRAFT FROM THE SERVICE TRUCK TO THE GROUND FOR FURTHER MAINTENANCE THE AIRCRAFT LOST POWER TO THE TAIL ROTOR CAUSING THE AIRCRAFT TO ROTATE 4 TO 5 TIMES BEFORE IMPACTING THE GROUND.

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 WPR11LA282Accident · No injuriesLimited investigationFinal reportHanford, CAThe separation of the tail rotor drive gear shaft due to torsional fatigue of its threaded portion, which resulted in a loss of tail rotor control.Jun 23, 2011 · Substantial damage