- Date
- March 8, 2008, 15:00 local (20:00 UTC)
- Place
- Westport, OK
- Injuries
- 2 uninjured
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N5251BWilley Rotorway Exec 90
- Defining event
- Maneuvering: Electrical system malf/failure
- Weather
- Visual (VMC) · Day
- Status
- Completed · report April 30, 2008
- Report
- Approved by Office Director
- Parties
- FAA FSDO
- FAA report
- 20080308012169A
- Case key
- 67640
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
An unsuccessful precautionary landing due to an electrical system malfunction.
Findings · 2
NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.
Sequence of events
The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.
Analysis
The certified flight instructor and the student pilot were on an instructional flight to practice autorotations and simulated engine failures. About 45 minutes into the flight the instructor noticed the engine tachometer read lower than the rotor tachometer. The student pilot checked the battery voltage and said that it was "low". The instructor reported that the engine's fuel pump and ignition systems were not independent and he did not want to risk a downwind autorotation landing. When the instructor saw the rotor tachometer drop to 90 percent, he initiated an autorotation, assuming the helicopter had or was about to lose engine power. During the landing the left skid sank into the soft terrain and the helicopter subsequently rolled on to its side. The helicopter sustained substantial damage during the precautionary landing.
Factual narrative
The certified flight instructor and the student pilot were on an instructional flight to practice autorotations and simulated engine failures. About 45 minutes into the flight the instructor noticed the engine tachometer read lower than the rotor tachometer. The student pilot checked the battery voltage and said that it was "low". The instructor reported that the engine's fuel pump and ignition systems were not independent and he did not want to risk a downwind autorotation landing. When the instructor saw the rotor tachometer drop to 90 percent, he initiated an autorotation, assuming the helicopter had or was about to lose engine power. During the landing the left skid sank into the soft terrain and the helicopter subsequently rolled on to its side. The helicopter sustained substantial damage during the precautionary landing.
Aircraft
- Registration
- N5251B
- Reported as
- Willey Rotorway Exec 90
- Category
- Helicopter, amateur-built
- Serial number
- 5251
- Airframe hours
- 983
- Engine
- Rotorway RW-100, reciprocating
- Damage
- Substantial damage
- Flight
- Instructional · Part 91
- Airworthiness certificate
- Special, Experimental (Special)
- Last inspection
- Condition · March 1, 2008
- Departed
- 95F · Cleveland, OK
- Destination
- 4F1 · Westport, OK
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 · 2
As NTSB recorded them. NTSB leaves out names.
- Role
- Flight instructor
- Age
- 48
- Injuries
- None
- Certificate
- Commercial
- Airplane ratings
- Single-engine land
- Instrument ratings
- Helicopter
- Medical
- Class 2, With waivers/limitations
- Last flight review
- November 1, 2007
- Seat
- Front
- Flight hours
- 498 total · 22 in this make and model · 113 in the last 90 days · 19 in the last 30 days · 5 in the last 24 hours
- Role
- Student pilot
- Age
- 32
- Injuries
- None
- Certificate
- Sport Pilot
- Airplane ratings
- Single-engine land
- Medical
- Sport pilot
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 10° at 12 knots, gusting 16
- Visibility
- 10 statute miles
- Lowest ceiling
- 6,000 ft overcast
- Temperature
- 36 °F, dew point 23 °F
- Altimeter
- 30.13 inHg
- Observed at
- KRVS, 20 nm away
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.