- Date
- March 18, 2010, 14:55 local (21:55 UTC)
- Place
- Arlington, WA
- Injuries
- 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Landing
- Aircraft
- N66PBCarr RV-4
- Defining event
- Landing-landing roll: Landing gear collapse
- Weather
- Visual (VMC) · Day
- Status
- Completed · report July 18, 2011
- Report
- Approved by Office Director
- NTSB office
- Western Pacific Region
- Parties
- FAA FSDO
- FAA report
- 20100318029809A
- Case key
- 75552
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 failure of both main landing gear's drag link bolts in overstress and the subsequent collapse of the landing gear during landing rollout.
Findings · 1
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 pilot said that when he took off and retracted the airplane's landing gear, only the tailwheel retracted. He lowered the landing gear and saw three green lights, indicating that all three landing gear were down and safe for landing. He then proceeded to his destination with the main landing gear down. During landing rollout at his destination, the left main landing gear collapsed. The airplane departed the left side of the runway before the right main landing gear collapsed as well. When the left wing's main landing gear collapsed outward, it damaged the wing structure and punctured the left fuel tank. The skin on the top of the right wing and the right aileron were wrinkled. Postaccident examination of the landing gear revealed that both main landing gear drag link bolts failed. These bolts were welded to the back of each main landing gear as part of their landing retraction system. Examination of photographs of the broken bolts by an NTSB metallurgist revealed that each bolt exhibited cantilever beam bending in overstress. The quality of the photographs was inadequate to determine if fatigue played a role.
Factual narrative
On March 18, 2010, approximately 1455 Pacific daylight time, a Carr RV-4 experimental amateur-built airplane, N66PB, sustained substantial damage when the left main landing gear collapsed during landing rollout at the Arlington Municipal Airport, Arlington, Washington. The airline transport pilot, the sole occupant, was not injured. The owner/pilot was operating the airplane under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the personal flight, which had originated from Burlington, Washington, approximately 1430. A flight plan had not been filed. The pilot said that when he took off and retracted the airplane's landing gear, only the tail wheel retracted. He lowered the landing gear, and got three green lights indicating that all three landing gear were down and safe for landing. He then proceeded to Arlington, where during the landing roll out on runway 34, the left main landing gear collapsed. The airplane departed the left side of the runway and subsequently the right main landing gear collapsed. When the left wing's main landing gear collapsed outward, it damaged the wing structure and punctured the left fuel tank. The skin on the top of the right wing and the right aileron were wrinkled. Postaccident examination of the landing gear revealed that both main landing gear drag link bolts failed. These bolts were welded to the back of each main landing gear as part of their landing retraction system. Examination of photographs of the broken bolts by an NTSB metallurgist revealed that each bolt exhibited cantilever beam bending in overstress. The quality of the photographs was inadequate to determine if fatigue played a role.
Aircraft
- Registration
- N66PB
- Reported as
- Carr RV-4
- Category
- Airplane, amateur-built
- Serial number
- 2953
- Airframe hours
- 635
- Engine
- Lycoming O&VO-360 SER, 180 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Personal · Part 91
- Operator
- Grover P. Best
- Registered owner
- Grover P. Best
- Airworthiness certificate
- Special, Experimental (Special)
- Last inspection
- Condition · November 3, 2009
- Departed
- BVS · Burlington, WA
- Destination
- AWO · Arlington, WA
- Flight plan
- Unknown
- Airport
- AWO · Arlington Municipal Arpt, runway 34, 5,332 × 100 ft, asphalt
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
- 69
- Injuries
- None
- Certificates
- Airline transport, Flight engineer
- Airplane ratings
- Single-engine sea, Single-engine land, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 3, With waivers/limitations
- Last flight review
- August 5, 2009
- Seat
- Front
- Flight hours
- 20,000 total · 435 in this make and model · 12,000 as pilot in command · 6 in the last 90 days · 2 in the last 30 days · 1 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 310° at 11 knots
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 50 °F, dew point 37 °F
- Altimeter
- 30.46 inHg
- Observed at
- AWO
Docket · 2
The files NTSB released with the investigation on June 7, 2011, on NTSB’s docket system: statements, records, photos and specialists’ reports. 490 KB in all.
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 N66PB · 1
Matched to the same aircraft by N-number and date.