# NTSB ATL90GA010: Hiller UH-12D, N63LC, Mentor, OH, October 23, 1989

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Final report
- Date: October 23, 1989, 14:05 local (18:05 UTC)
- Place: Mentor, OH
- Coordinates: 41.689479, -81.330116 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=41.6895&lon=-81.3301&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 2 serious
- Status: Completed, report March 25, 1991
- Report: Approved by Office Director
- NTSB case key (mKey): 8151
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL90GA010
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/8151/pdf
- Page: https://openairdocs.org/ntsb/ATL90GA010

## Probable cause

IMPROPER IN-FLIGHT PLANNING/DECISION BY THE PILOT. FACTORS RELATED TO THE ACCIDENT WERE: THE PILOT'S IMPROPER COMPENSATION FOR WIND CONDITIONS AND TREES.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of control - in flight, maneuvering
  - in-flight planning/decision - improper, pilot in command (cause)
  - compensation for wind conditions - improper, pilot in command (contributing factor)
  - directional control - not possible
- In flight collision with object, descent - uncontrolled
  - object - tree(s) (contributing factor)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE HELICOPTER (HEL) WAS BEING USED TO TAKE A RADIO TO A COUNTY EMERG OPNS CENTER TO TEST ITS RECEPTION AT 500' AGL. LOADED WITH THE RADIO, 27 GAL OF FUEL & A PAX, IT WAS WITHIN ITS WT & BALANCE LMTS. AS THE HEL WAS APCHG THE 500' LCTN &WAS BEING SLOWED IN LIGHT WIND (EST FM 160 DEG AT 5 KTS), THE PLT FELT A MODERATE VIBRATION. HE INTERPRETED THIS AS A TAIL ROTOR PROBLEM & REACTED BY ADJUSTING THE THROTTLE & OPERG THE PEDALS. HE STATED THAT THIS SEEMED ONLY TO OSCILLATE THE TAIL & CAUSE A LOSS OF LIFT. ALSO, HE NOTED THE VIBRATION SLOWED IN FREQ & BCM MORE VIOLENT. HE ATMTD TO INCREASE ENG RPM & RAISE THE COLLECTIVE TO GAIN ALT, BUT THE HEL BGN SPIRALING. IT THEN CRASHED ON WOODED TERRAIN & BGN BURNING, BUT THE OCCUPANTS EGRESSED. NO PREIMPACT PART FAILURE/MALFUNCTION WAS FND THAT WOULD HAVE RESULTED IN THE ACDNT, THOUGH SOME BINDING WAS NOTED IN THE PITCH CHANGE MECHANISM. SVRL WITNESSES INDCD THAT BEFORE THE ACDNT, THE HEL APCHD THE AREAFM THE NE & BGN SLOWING, AS IF THE PLT INTENDED TO HOVER. IT THEN BGN ROTATING TO THE RGT & SUBSEQUENTLY CRASHED.

## Aircraft

- Registration: [N63LC](https://openairdocs.org/deregistered/N63LC-1992-02-05), registration cancelled 1992-02-05, S/N 1402 (OpenAirDocs)
- Reported make and model: HILLER UH-12D
- Registry model: [Hiller UH-12D](https://openairdocs.org/model/hiller-uh-12d) (registry code 4360118) (OpenAirDocs)
- Category: Helicopter
- Serial number: 1402
- Airframe hours: 5094
- Engines: LYCOMING VO-435-23B 260 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Public aircraft, Part 91
- Registered owner: Lake Co Board Of Commissioners
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, July 16, 1988, 20 hours before
- Departed: 2G1, CONCORD, OH

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 58; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: center; flight hours: 770 total, 170 in this make and model, 643 as pilot in command, 15 in the last 90 days, 4 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 160° at 5 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 70 °F, dew point -0 °F
- Altimeter: 30.00 inHg

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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