FTW95LA368

NTSB accident investigation · Bell 206L-1 · Oklahoma City, OK · August 27, 1995

Accident · No injuriesLimited investigationFinal report
Date
August 27, 1995, 18:49 local (23:49 UTC)
Place
Oklahoma City, OK
Injuries
4 uninjured
Damage
Substantial damage
Phase of flight
Takeoff
Aircraft
N2070ZBell 206L-1
Weather
Visual (VMC) · Dusk
Status
Completed · report February 14, 1996
Report
Approved by Office Director
FAA report
19950827046139A
Case key
19560

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

The failure of the low side of the turbine governor. A factor the lack of suitable terrain for the 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 powerTakeoff
Turboshaft engine,free turbine governor - failure,partialCause
Forced landingEmergency landing after takeoff
Autorotation - initiatedPilot in command
Terrain condition - none suitableFactor
Terrain condition - congested/confined area
Terrain condition - rough/uneven
Hard landingEmergency landing after takeoff
Flare - delayedPilot in commandCause
Rotor rpm - not possiblePilot in commandCause

Analysis

After landing the EMS helicopter at the roof top helipad, the pilot was informed that the hospitals' elevator was inoperative and the stairway would not accommodate the incubator. Following the takeoff, a loss of engine power occurred, and the pilot initiated an autorotation. Below the helicopter was a full parking lot, a street, and trees. The pilot flared the helicopter over the trees and recalled lowering the pitch and applying forward cyclic in an attempt to regain RPM and airspeed. The helicopter touched down in an uneven field and skidded 30 yards before coming to rest. Damage occurred to the horizontal stabilizer winglets, main rotor blades, rear landing gear crosstube, and the tailrotor driveshaft cover. The company reported a 'low side governor failure' as the cause of the power loss.

Factual narrative

On August 27, 1995, at 1849 central daylight time, a Bell 206L-1, N2070Z, sustained substantial damage during a forced landing near Oklahoma City, Oklahoma. The airline transport rated pilot, two medical technicians, and one infant did not receive injuries. The flight was being operated as an Emergency Medical Service (EMS) flight by St. Louis Helicopter Airways, Inc., under Title 14 CFR Part 135. The flight originated in Hugo, Oklahoma, at 1728. Visual meteorological conditions prevailed and a company VFR flight plan was filed.

During interviews, conducted by the Federal Aviation Administration (FAA) inspector, and on the Pilot/Operator Report the following information was reported. The purpose of the flight was to transport the infant in an incubator to Mercy Hospital. After landing the helicopter at the roof top helipad, the pilot was informed that the elevator was inoperative and the stairway would not accommodate the incubator. The flight departed the roof top and during the descent toward the ground helipad, a loss of engine power occurred. The pilot initiated an autorotation; however, directly below the helicopter was "a full parking lot, then a row of trees, then a 4 lane street with more trees." Utilizing "pitch and aft" cyclic, the pilot flared the helicopter over the trees. Then the pilot recalled "lowering the pitch slightly and applying a little forward cyclic to try and build a little RPM and airspeed." The aircraft touched down in a "grassy, undulating field" and "skidded 30 yards" before coming to rest.

The FAA inspector examined the helicopter and talked with the chief pilot. Damage occurred to the upper portions of the horizontal stabilizer winglets, the lower surface of the main rotor blades, the rear landing gear crosstube, and the tailrotor driveshaft cover. The chief pilot reported "a low side governor failure as the cause of the power loss."

Aircraft

Registration
N2070Z
Reported as
Bell 206L-1
Category
Helicopter
Serial number
45730
Airframe hours
7,953
Engine
Allison 250-C28, 500 horsepower, turbo shaft
Damage
Substantial damage
Flight
Part 135
Registered owner
St. Louis Helicopter Airways
Airworthiness certificate
Standard, Normal
Last inspection
Continuous airworthiness · August 23, 1995 · 12 hours before
Departed
Hugo, OK
Flight plan
Company VFR

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
46
Certificate
Airline transport
Instrument ratings
Helicopter
Medical
Class 2, Valid Medical--no waivers/lim.
Seat
Right
Flight hours
7,583 total · 2,500 in this make and model · 6,850 as pilot in command · 41 in the last 90 days · 21 in the last 30 days · 6 in the last 24 hours

Weather

Conditions
Visual (VMC) · Dusk
Wind
180° at 5 knots
Visibility
5 statute miles
Lowest ceiling
None
Temperature
95 °F

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.