# NTSB FTW94LA296: Hiller UH-12E, N12RF, Grand Junction, CO, September 9, 1994

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: September 9, 1994, 12:40 local (18:40 UTC)
- Place: Grand Junction, CO
- Coordinates: 39.109741, -108.530654 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.1097&lon=-108.5307&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report April 5, 1995
- Report: Approved by Office Director
- NTSB case key (mKey): 19159
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW94LA296
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/19159/pdf
- Page: https://openairdocs.org/ntsb/FTW94LA296

## Probable cause

IMPROPER REMEDIAL ACTION IN CORRECTING FOR EXCESSIVE SPEED AND SINK RATE DURING AN AUTOROTATION. FACTORS WERE: HIGH DENSITY ALTITUDE, EXCESSIVE AIRSPEED AND SINK RATE.

## Sequence of events

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

- Hard landing, landing
  - weather condition - high density altitude (contributing factor)
  - autorotation - performed, pilot in command
  - proper descent rate - not maintained, pilot in command (contributing factor)
  - airspeed - excessive, pilot in command (contributing factor)
  - remedial action - improper, pilot in command (cause)

## Analysis

WHILE ON A SOLO INSTRUCTIONAL FLIGHT, PRACTICING TOWARDS GAINING A HELICOPTER RATING, THE PILOT WAS CONDUCTING A PRACTICE  AUTOROTATION TO A SAND BAR. THE AIRSPEED AND SINK RATE BECAME EXCESSIVE AND THE HELICOPTER LANDED HARD RESULTING IN THE MAIN ROTOR BLADES STRIKING THE TAIL BOOM.

## Factual narrative

On September 9, 1994, at 1240 mountain daylight time, a Hiller UH-12E helicopter, N12RF, sustained substantial damage during a hard landing.  The pilot was not injured on this local area solo instructional flight which departed Grand Junction, Colorado, at 1219.  No flight plan was filed and visual meteorological conditions prevailed.

The pilot was not helicopter rated and was in the process of receiving instruction towards gaining that rating.

The pilot stated he was practicing autorotations to a sand bar near the Colorado River. He said his forward speed and descent rate became excessive and he applied aft cyclic to recover.   Touchdown was hard and the main rotor struck the tail boom.

Density altitude at the time of the accident was approximately 7,500 feet and the wind was light and variable.

## Aircraft

- Registration: N12RF (not matched to a registry record)
- Reported make and model: HILLER UH-12E
- Category: Helicopter
- Serial number: 2102
- Airframe hours: 7868
- Engines: LYCOMING VO-540-C2A 305 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Fowler, Richard L
- Registered owner: Helicopter One
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, April 5, 1994, 71 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; commercial; airplane ratings: single-engine land, multi-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 11,175 total, 12 in this make and model, 11,150 as pilot in command, 85 in the last 90 days, 34 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 70 statute miles
- Lowest ceiling: 10,000 ft broken
- Temperature: 84 °F, dew point 39 °F
- Altimeter: 30.00 inHg
- Observed at: GJT, 3 nm away

## 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 19940909026059A](https://openairdocs.org/incident/19940909026059A), Sep 9, 1994: Hiller UH12E, Grand Junction, CO, Substantial damage. Practice autorotation to sandbar. Allowed rotor speed decay. Landed hard. Rotors chopped off tailboom.

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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