- Date
- August 7, 1990, 12:30 local (20:30 UTC)
- Place
- Tok, AK
- Injuries
- 1 serious
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N58000Aerospatiale SA-315B
- Weather
- Visual (VMC) · Day
- Status
- Completed · report June 19, 1992
- Report
- Approved by Office Director
- NTSB office
- Alaska Regional Office
- Safety recommendations
- Yes
- FAA report
- 19900807031499A
- Case key
- 5420
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
Improper installation of the fuel filter element in the aircraft by company/maintenance personnel, and subsequent contamination of the fuel system by unfiltered fuel. Factors related to the accident were: inadequate design of the fuel filter assembly, which allowed the improper installation of the filter element, the mechanics lack of familiarity with the aircraft, and failure of ground personnel to insure that fuel from the fuel tanker was free of contamination.
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.
Analysis
The helicopter was being used in an external load opn to carry cargo with a 100 ft cable. While hovering out of ground effect, the eng lost pwr. A subsequent hovering autorotation resulted in a hard landing. An exam revealed the loss of power was due to fuel contamination although an airframe fuel filter was installed in the main fuel supply line. An exam revealed the filter element had been installed backward in the filter canister. This allowed contaminated fuel to bypass the filter element & enter the eng fuel ctl unit. The reverse instln also resulted in an inop 'fuel filter clogged' warning lgt & prevented the pressure differential button on the filter housing fm extdg. The filter had been inspected & reinstld drg a 100 hr inspn, 17 flt hrs bfr the acdnt. This work was done by a plt under supervision of a mechanic. The mechanic had no prev experience with this make & model of helicopter. 'Top' & 'bottom' were stenciled on the filter element in french. Contaminated fuel was also fnd in the fuel truck.
Aircraft
- Registration
- N58000
- Reported as
- Aerospatiale SA-315B
- Category
- Helicopter
- Serial number
- 2639
- Airframe hours
- 3,607
- Engine
- Turbomeca ARTOUSTE IIIB, 878 horsepower, turbo shaft
- Damage
- Substantial damage
- Flight
- Other work use · Part 133
- Registered owner
- Pegasus Helicopters, Inc.
- Airworthiness certificate
- Standard, Normal
- Last inspection
- 100 hour · August 4, 1990 · 17 hours before
- Departed
- TKJ · Tok, AK
- Flight plan
- Company VFR
- Airport
- NONE
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
- 43
- Certificate
- Commercial
- Airplane ratings
- Single-engine land
- Instrument ratings
- Airplane
- Medical
- Class 2, Valid Medical--w/ waivers/lim
- Seat
- Right
- Flight hours
- 13,000 total · 5,000 in this make and model · 13,000 as pilot in command · 265 in the last 90 days · 98 in the last 30 days · 4 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 220° at 10 knots, gusting 12
- Visibility
- 50 statute miles
- Lowest ceiling
- 5,000 ft broken
- Temperature
- 63 °F, dew point -0 °F
- Altimeter
- 29.00 inHg
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.