Hughes OH-6A N12UT

Summary

On 31 July 1994 at about 00:50 local time, a Hughes OH-6A registered N12UT was involved in an accident near Duchesne, Utah, United States. One person was on board and one died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

31 July 1994 at 00:50

Classification

Accident

Location

Duchesne, Utah, United States

Coordinates

40.4901, -111.8403

Aircraft

Hughes OH-6A

Registration

N12UT

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Public Use

Purpose of flight

Public Use

Phase of flight

Not recorded

Route

Salt Lake City → Unknown

Aircraft damage

Destroyed

Weather

Unk

Light

Day

NTSB number

SEA94GA203

1 person died.

THE PILOT'S IMPROPER IN-FLIGHT PLANNING/DECISION AND FAILURE TO MAINTAIN SUFFICIENT ALTITUDE/CLEARANCE FROM THE SURROUNDING TERRAIN. FACTORS RELATED TO THE ACCIDENT WERE: THUNDERSTORMS IN THE AREA (REQUIRING THE PILOT TO DEVIATE FROM THE DESIRED COURSE), HIGH MOUNTAINOUS TERRAIN, AND HIGH DENSITY ALTITUDE,

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

WHILE RETURNING TO SALT LAKE CITY FROM THE SOUTHEAST, THE PILOT REPORTED SEEING THUNDERSTORMS IN THE AREA. AT ABOUT 1843 MDT, THE HELICOPTER CHANGED COURSE AND PROCEEDED OVER MOUNTAINOUS TERRAIN WITH A MODE C ALTITUDE READOUT OF 9600 TO 9800 FEET MSL. THE TERRAIN ELEVATION ALONG THE FLIGHT PATH CHANGED FROM 7700 TO ABOUT 10,000 FEET. SHORTLY AFTER PASSING OVER TERRAIN NEAR 10,000 FEET, THE PILOT RADIOED A MAYDAY AND DECLARED THAT THE ENGINE WAS LOSING POWER. THE HELICOPTER BEGAN A DESCENT, ROUGHLY FOLLOWING A CANYON DRAINAGE AREA. SUBSEQUENTLY, IT CRASHED AT AN ELEVATION OF APPROXIMATELY 8850 FEET AFTER IMPACTING TREES. THE LONGITUDINAL WRECKAGE DISTRIBUTION WAS MINIMAL, INDICATING SLOW FORWARD VELOCITY AT TREE IMPACT. AN EXAM OF THE ENGINE REVEALED EVIDENCE OF POWER PRODUCTION DURING IMPACT; NO PREIMPACT PART FAILURE/MALFUNCTION WAS FOUND. THE DENSITY ALTITUDE WAS ESTIMATED TO BE ABOUT 12,000 FEET, AND THE HELICOPTER'S GROSS WEIGHT AT THE TIME OF THE ACCIDENT WAS ESTIMATED TO BE 1977 POUNDS. PERFORMANCE EVALUATION SHOWED THAT WITH THESE CONDITIONS, THE HELICOPTER WOULD HAVE BEEN UNABLE TO MAINTAIN A HOVER OUT OF GROUND EFFECT. THE ROTOR BLADES SHOWED ROTATIONAL ENERGY IMPACT SIGNATURES.

Quoted verbatim from the NTSB record.