ATL88LA030

NTSB accident investigation · Hiller UH-12B · Newnan, GA · November 7, 1987

Accident · No injuriesLimited investigationFinal report
Date
November 7, 1987, 13:30 local (18:30 UTC)
Place
Newnan, GA
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Approach
Aircraft
N922TEHiller UH-12B
Weather
Visual (VMC) · Day
Status
Completed · report February 14, 1989
Report
Approved by Office Director
FAA report
19871107067439A
Case key
7671

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Airframe/component/system failure/malfunctionApproach - vfr pattern - final approach
Rotor drive system,tail rotor gearbox(90 deg) - vibrationCause
Rotor drive system,tail rotor gearbox(90 deg) - fatigueCause
Rotor drive system,tail rotor gearbox(90 deg) - separationCause
Autorotation - performedPilot in command
Roll overLanding
Directional control - reduced

Analysis

The tail rotor 90 degree gearbox mounting flange fractured during apch to land, while the helicopter was at about 75 ft AGL. The gearbox subsequently separated from the helicopter. The plt initiated an autorotation. The helicopter rolled over on ldg. Metallurgical analysis indicated that the flange failed as a result of extensive preexistent fatigue cracking, and that the cracking was the result of excessive vibration.

Aircraft

Registration
N922TE
Reported as
Hiller UH-12B
Category
Helicopter
Serial number
714
Engine
Franklin 6V-335-B, 210 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Unlimited Directions,Inc.
Registered owner
Unlimited Directions, Inc
Departed
Carrollton, GA

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
39
Certificate
Commercial
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Center
Flight hours
3,141 total · 28 in this make and model · 43 in the last 90 days · 2 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Lowest ceiling
None

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.

Other investigations on N922TE · 1

Matched to the same aircraft by N-number and date.