- Date
- February 9, 1993, 14:55 local (21:55 UTC)
- Place
- Chandler, AZ
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Initial climb
- Aircraft
- N89678Cobb Intl Exec 90
- Weather
- Visual (VMC) · Day
- Status
- Completed · report November 15, 1993
- Report
- Approved by Office Director
- FAA report
- 19930209002169A
- Case key
- 27918
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
The manufacturer's inadequate quality control which resulted in the fatigue of the valve stem. The soft terrain contributed to this accident.
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's engine failed while on the crosswind leg. The surrounding terrain was congested forcing the pilot to land in an area which was downwind. The helicopter nosed down on landing in the soft terrain. Examination of the engine disclosed that an intake valve failed and lodged in the piston. Metallurgical examination revealed that the valve stem failed in fatigue. The fatigue was precipitated by the manufacturer's improper quality control which failed to assure that the valve was ground before it was plated.
Aircraft
- Registration
- N89678
- Reported as
- Cobb Intl Exec 90
- Category
- Helicopter
- Serial number
- R.I. 5026
- Airframe hours
- 541
- Engine
- Rotorway 162, 150 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Other work use · Part 91
- Operator
- Cobb International, Inc., doing business as Rotorway International
- Registered owner
- Cobb International, Inc.
- Airworthiness certificate
- Special, Experimental (Special)
- Last inspection
- Continuous airworthiness · January 11, 1993 · 20 hours before
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
- 37
- Certificates
- Commercial, Flight instructor
- Airplane ratings
- Single-engine land
- Medical
- Class 2, Valid Medical--no waivers/lim.
- Seat
- Left
- Flight hours
- 1,059 total · 611 in this make and model · 979 as pilot in command · 111 in the last 90 days · 55 in the last 30 days · 2 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 270° at 12 knots
- Visibility
- 35 statute miles
- Lowest ceiling
- None
- Temperature
- 61 °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 N89678 · 3
Matched to the same aircraft by N-number and date.