Saturday, July 8, 2017

Piper PA-28-140, N5808U: Accident occurred June 04, 2013 at Skagit Regional Airport (KBVS), Washington

Additional Participating Entity:
Federal Aviation Administration / Flight Standards District Office; Renton, Washington

Aviation Accident Final Report - National Transportation Safety Board: https://app.ntsb.gov/pdf

Investigation Docket - National Transportation Safety Board: https://dms.ntsb.gov/pubdms

Aviation Accident Data Summary - National Transportation Safety Board: https://app.ntsb.gov/pdf

http://registry.faa.gov/N5808U

NTSB Identification: WPR13LA262
14 CFR Part 91: General Aviation
Accident occurred Tuesday, June 04, 2013 in Burlington, WA
Probable Cause Approval Date: 06/11/2014
Aircraft: PIPER PA-28-140, registration: N5808U
Injuries: 1 Uninjured.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

During the landing roll, the airplane began to veer right, and the pilot applied left rudder and left braking action to align the airplane with the runway; however, both actions were ineffective. The airplane departed the right side of the runway and impacted an airport sign and a ditch. Postaccident examination of the left rudder bar assembly found that it had failed due to a fatigue crack. A rusted brown oxidized area near the center of the crack and surface features consistent with slow-growth fatigue indicated that the crack had been growing incrementally over a period of years. A review of the manufacturer’s periodic inspection checklist, maintenance manual, and Service Letter No. 671 indicated that the rudder bar assembly should be inspected every 100 hours specifically for cracks in the area where the airplane’s rudder bar failed. If maintenance personnel had inspected the airplane in accordance with these documents, the crack likely would have been found and the accident prevented. 

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
The failure of the rudder bar assembly during landing due to a fatigue crack. Contributing to the accident was the failure of maintenance personnel to perform an adequate inspection of the rudder bar assembly. 

On June 4, 2013, at about 0930 Pacific daylight time, a Piper PA-28-140, N5808U, was substantially damaged when it struck an airport sign following a loss of directional control during landing roll at Skagit Regional Airport, Burlington, Washington. The private pilot, the sole occupant, was not injured. The pilot/owner was operating the airplane under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the personal cross-country flight, which had originated from Friday Harbor, Washington, approximately 20 minutes before the accident. A flight plan had not been filed. 

The pilot said that while on landing roll, he applied left rudder to straighten the airplane, with no response. He said he attempted to correct the right veering tendency with left braking action, and that was ineffective as well. The airplane departed the right side of the runway and impacted an airport sign and a ditch, which damaged the right wing. 

Postexamination of the left rudder control bar found that it had failed. Examination of the rudder control bar at the NTSB Materials Laboratory found a fatigue crack, which originated from the edge of a weld. There was a rusted brown oxidized area near the middle of the crack, and the surface of this area had topography and crack patterns consistent with slow growth fatigue progressing from the exterior surface radially through the tube wall.

The airplane was manufactured in 1970, and according to the owner, it had an airframe total time of 3,479 hours when the accident occurred. The most recent annual inspection was completed on May 25, 2013.

A review of the Piper Aircraft's periodic inspection checklist, maintenance manual, and Service Letter No. 671 dated October 5, 1973, indicated that the rudder bar assembly should be inspected every 100 hours specifically for cracks in the area where the airplane's rudder bar failed. Further, the Service Letter stated that these periodic inspections could be discontinued if two reinforcement doublers were fabricated and welded to the rudder bar in the affected area. There were no reinforcement doublers on the airplane's rudder bar.

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