# NTSB FTW84LA099: Hiller UH-12C, N63MC, Imperial, TX, December 16, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: December 16, 1983, 14:30 local (20:30 UTC)
- Place: Imperial, TX
- Coordinates: 31.269086, -102.690719 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=31.2691&lon=-102.6907&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 21236
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW84LA099
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/21236/pdf
- Page: https://openairdocs.org/ntsb/FTW84LA099

## Sequence of events

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

- Miscellaneous/other, cruise - normal
  - reason for occurrence undetermined (contributing factor)
  - fuselage - vibration
- Hard landing, landing - flare/touchdown
  - precautionary landing - performed, pilot in command
  - level off - improper, pilot in command (cause)

## Analysis

THE PLT REPORTED THAT WHEN HE WAS IN CRUISE FLT AT 300 FT AGL, A SUDDEN VIOLENT SHUDDER WENT THRU THE WHOLE HELICOPTER, THEN THE SHUDDER STOPPED. HE NOTED NO CHANGE IN THE FLIT CHARACTERISTICS OR ENG POWER. THE PLT ELECTED TO MAKE A PRECAUTIONARY LANDING BY FLYING DIRECTLY TO THE GROUND WITH NO HOVER. DURING THE LANDING, THE TAIL BOOM STRUCK THE GROUND, THEN THE MAIN ROTOR BLADES STRUCK THE TAIL BOOM. NO CAUSE FOR THE 'SHUDDER' WAS FOUND.

## Aircraft

- Registration: [N63MC](https://openairdocs.org/deregistered/N63MC-2014-12-16), registration cancelled 2014-12-16, S/N 915 (OpenAirDocs)
- Reported make and model: HILLER UH-12C
- Registry model: [Hiller UH-12C](https://openairdocs.org/model/hiller-uh-12c) (registry code 4360116) (OpenAirDocs)
- Registry engine: [Franklin 6VS-335 series](https://openairdocs.org/engine/franklin-6vs-335-series) (registry code 27040, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 915
- Airframe hours: 2941
- Engines: FRANKLIN 6V4-200-C33 210 horsepower reciprocating
- Damage: Substantial damage
- Flight: Business, Part 91
- Registered owner: James R. Blair
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, March 25, 1983
- Departed: FORT STOCKTON, TX
- Destination: MAF, MIDLAND, TX

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 43; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 4,997 total, 26 in this make and model, 4,997 as pilot in command, 132 in the last 90 days, 6 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 39 °F

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19831216061559A](https://openairdocs.org/incident/19831216061559A), Dec 16, 1983: Hiller UH12C, Imperial, TX, Substantial damage. Experienced a shudder in cruise flight. Elected to land. Tail boom hit ground, then chopped off by main rotor.

## Other investigations on N63MC (1)

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.

- [NTSB NYC78FHM27](https://openairdocs.org/ntsb/NYC78FHM27), Aug 29, 1978: Hiller 12C (N63MC), Neptune, NJ, substantial damage

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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