FTW94LA144

NTSB accident investigation · Hiller UH-12E · Osage, AR · May 4, 1994

Accident · Minor injuriesLimited investigationFinal report
Date
May 4, 1994, 18:30 local (23:30 UTC)
Place
Osage, AR
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N90469Hiller UH-12E
Weather
Visual (VMC) · Day
Status
Completed · report November 14, 1994
Report
Approved by Office Director
Case key
19047

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

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Probable cause

Fuel exhaustion due to the pilot's failure to refuel and the lack of suitable terrain for a forced landing.

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.

Loss of engine power(total) - nonmechanicalCruise - normal
Fluid,fuel - exhaustionFactor
Refueling - not performedPilot in commandCause
Forced landingDescent - emergency
In flight collision with terrain/waterDescent - emergency
Terrain condition - mountainous/hilly
Terrain condition - none suitableCause

Analysis

According to the pilot, the helicopter was serviced with 30 gallons of fuel for an aerial application flight to dispense 100 gallons of pesticides. After a 45 minute sortie, the helicopter was en route back to the loading site, over heavily wooded mountainous terrain, when the pilot experienced a loss of engine power. The engine regained power temporarily, and lost power for a second time 5 to 8 seconds later. The pilot autorotated above the tree tops and settled through the trees coming to rest in an upright position. There was no evidence of a fuel spill and no fuel was found in the fuel cell. The average fuel burn rate is 25 to 26 gallons per hour. The engine was successfully run in an engine test cell.

Factual narrative

On May 4, 1994, at 1830 central daylight time, a Hiller UH-12E helicopter, N90469, was substantially damaged following a loss of engine power near Osage, Arkansas. The airline transport rated pilot sustained minor injuries. Visual meteorological conditions prevailed for the aerial application flight.

According to the operator, the turbine powered helicopter was supporting a gypsy moth eradication program within the Ozark National Forest. The pilot stated that the helicopter was serviced with 100 gallons pesticides and 30 gallons of Jet A fuel for the ninth sortie of the day.

Approximately 45 minutes later, while en route back to the load site, the engine lost power. The pilot stated that he entered autorotation, and the engine auto reignite restarted the engine. The pilot added that he turned towards an open field to make a precautionary landing, and approximately 5 to 8 seconds later, the engine lost power for the second time.

The pilot reentered an autorotation to the heavily wooded area ahead and was able stop all forward motion above the tree tops, settling through the trees. After falling 40 to 50 feet, the helicopter came to rest in the upright position lodged between the tree trunks.

According to the operator, the fuel cell and the fuel lines were not compromised during the crash sequence. No fuel was found in the fuel cell, and there was no evidence of a fuel spill on the ground. According to the engine manufacturer, the average fuel burn rate is 25 to 26 gallons per hour. A successful engine run was accomplished in a test cell, and no anomalies were found with either the fuel control or associated fuel system components.

Aircraft

Registration
N90469
Reported as
Hiller UH-12E
Category
Helicopter
Serial number
2358
Airframe hours
5,989
Engine
Allison 250-C20B, 420 horsepower, turbo shaft
Damage
Substantial damage
Flight
Aerial application · Part 137
Registered owner
Evergreen Equity Inc
Airworthiness certificate
Special, Restricted (Special)
Last inspection
100 hour · April 13, 1994 · 10 hours before
Flight plan
Company VFR

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
46
Certificate
Airline transport
Airplane ratings
Multi-engine land, Single-engine land
Instrument ratings
Helicopter, Airplane
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Left
Flight hours
10,146 total · 210 in this make and model · 9,086 as pilot in command · 12 in the last 90 days · 11 in the last 30 days · 4 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
350° at 10 knots
Visibility
15 statute miles
Lowest ceiling
None
Temperature
72 °F, dew point 46 °F
Altimeter
30.00 inHg
Observed at
HRO, 13 nm away

Other investigations on N90469 · 2

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