FTW93LA228

NTSB accident investigation · Bell 206B · Pearland, TX · August 4, 1993

Accident · No injuriesLimited investigationFinal report
Date
August 4, 1993, 14:00 local (19:00 UTC)
Place
Pearland, TX
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Enroute
Aircraft
N16814Bell 206B
Weather
Visual (VMC) · Day
Status
Completed · report September 26, 1994
Report
Approved by Office Director
FAA report
19930804027659A
Case key
18807

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

Pilot's failure to maintain proper rotor RPM, the delayed flare, and improper touchdown. Factors were total failure of the power turbine due to oil starvation to the #8 bearing assembly.

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) - mech failure/malfClimb - to cruise
Fluid,oil - starvationFactor
Reason for occurrence undetermined
Engine assembly,bearing - failure,totalFactor
Forced landingDescent - emergency
Hard landingLanding - flare/touchdown
Autorotation - initiatedPilot in command
Rotor rpm - not maintainedPilot in commandCause
Flare - delayedPilot in commandCause
Touchdown - improperPilot in commandCause
Misc rotorcraft,tail boom - separation

Analysis

During a maintenance flight check following a turbine replacement, a total loss of engine power occurred. As the pilot began to cushion with collective during the autorotation the helicopter touched down, rocked forward and then back. The main rotors severed the tailboom. Examination of the engine revealed a lack of oil to the number eight bearing assembly.

Factual narrative

On August 4, 1993, at 1400 central daylight time, a Bell 206B, N16814, sustained substantial damage during a forced landing near Pearland, Texas. The airline transport rated pilot and a mechanic aboard the helicopter were not injured. Visual meteorological conditions prevailed for the local maintenance check flight.

The Pilot/Operator report and statement submitted by the pilot reported that he performed the preflight, and after a 10 minute ground run was cleared for takeoff. During initial climbout, at approximately 200 to 280 feet above the ground (AGL), the engine made a noise and decelerated.

An autorotation was initiated to an open field. The pilot stated that "at about 30 to 40 feet I began a gentle deceleration and reduced my ground speed to about 0 at about 4 feet and waited for the aircraft to settle, then I began to cushion with collective." He further stated "the aircraft touched down and rocked forward and then back." During the backward movement, the pilot heard a loud bang. Damage to the helicopter included a severed outboard portion of the tailboom.

The mechanic reported in the enclosed statement that he was aboard the helicopter for a maintenance operational flight check following a turbine replacement. He further reported that the engine "seized at about 300 feet" above the ground.

Examination of the engine by the operator and FAA inspectors (enclosed statement) indicated a lack of lubrication to the number eight bearing.

The representative of the engine manufacturer (enclosed report) examined the engine and found that the #8 bearing was "not fully engaged with the groove in the G. P. Support and the bearing had partially failed."

Aircraft

Registration
N16814
Reported as
Bell 206B
Category
Helicopter
Serial number
2229
Airframe hours
7,509
Engine
Allison 250-C20B, 420 horsepower, turbo shaft
Damage
Substantial damage
Flight
Part 91
Registered owner
Houston Helicopter, Inc.
Airworthiness certificate
Standard, Normal
Last inspection
100 hour · January 14, 1993 · 3 hours before
Departed
TX10
Destination
TX10

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
44
Certificates
Airline transport, Flight instructor
Instrument ratings
Helicopter
Medical
Class 2, Valid Medical--no waivers/lim.
Seat
Right
Flight hours
10,000 total · 2,500 in this make and model · 9,750 as pilot in command · 74 in the last 90 days · 35 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 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.

Other investigations on N16814 · 1

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