- Date
- July 7, 1994, 11:25 local (18:25 UTC)
- Place
- Portland, OR
- Injuries
- 2 uninjured
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N42WCRobinson R-22M
- Weather
- Visual (VMC) · Day
- Status
- Completed · report December 2, 1994
- Report
- Approved by Office Director
- FAA report
- 19940707017769A
- Case key
- 41968
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
Tail rotor gearbox failure due to inadequate assembly and inspection procedures by the manufacturer.
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 pilot attempted an autorotation after loss of tail rotor effectiveness. The tail boom and rotor struck the surface when the float equipped helicopter landed in the river. Investigation revealed that the tail rotor gearbox output shaft pinion retaining key had not been installed during assembly. The tail rotor hub and blade assembly were free to turn on the shaft at the time of investigation.
Factual narrative
On July 7, 1994, at 1125 Pacific daylight time, a Robinson R-22M, N42WC, sustained substantial damage during an autorotational forced landing to Ross Island beach, Portland, Oregon. The student pilot and certified flight instructor sustained minor injuries. No flight plan was filed for the instructional flight, which had departed Hillsboro, Oregon about 1105.
The pilot stated that he had lost tail rotor effectivness and attempted an autorototation from about 75 feet AGL. The pilot stated that the aircraft continued turning through two or three rotations before toching down. The aircraft landed near shoreline, with the tail rotor and boom striking the water.
Inspection revealed that the tail rotor gearbox (P/N A021-1) output shaft pinion (A545-1) retaining key (A114-2) was not installed at the time of factory assembly, allowing the tail rotor hub and blade to become disengaged.
Aircraft
- Registration
- N42WC
- Reported as
- Robinson R-22M
- Category
- Helicopter
- Serial number
- 1531M
- Airframe hours
- 460
- Engine
- Lycoming O-320-B2C, 131 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Instructional · Part 91
- Operator
- Hillsboro Helicopters, Inc.
- Registered owner
- West Coast Building Fasteners
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · January 28, 1994 · 22 hours before
- Departed
- HIO · Hillsboro, OR
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
- 38
- Certificates
- Private, Flight instructor, Commercial
- Airplane ratings
- Single-engine land
- Medical
- Class 2, Valid Medical--w/ waivers/lim
- Seat
- Left
- Flight hours
- 1,822 total · 1,475 in this make and model · 257 in the last 90 days · 101 in the last 30 days · 5 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 330° at 8 knots
- Visibility
- 30 statute miles
- Lowest ceiling
- None
- Temperature
- 81 °F, dew point 57 °F
- Altimeter
- 30.00 inHg
- Observed at
- HIO
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 N42WC · 1
Matched to the same aircraft by N-number and date.