# NTSB SEA94LA213: Piper PA-24-180, N5063P, Nehalem, OR, August 14, 1994 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 13, 1994, 18:45 local (Aug 14, 1994, 01:45 UTC) - Place: Nehalem, OR - Coordinates: 45.699768, -123.859397 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.6998&lon=-123.8594&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report May 18, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 42000 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA94LA213 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42000/pdf - Page: https://openairdocs.org/ntsb/SEA94LA213 ## Probable cause THE SEPARATION OF THE LANDING GEAR TRANSMISSION ASSEMBLY FROM ITS ATTACH BRACKET RIVETS DUE TO UNDETERMINED REASONS. IT WAS NOT POSSIBLE FOR THE LANDING GEAR TO BE LOCKED DOWN DURING THE LANDING ROLL DUE TO THIS SEPARATION. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, landing - roll - landing gear,normal retraction/extension assembly - separation (cause) - gear down and locked - not possible (cause) - miscellaneous,bolt/nut/fastener/clamp/spring - sheared - Gear collapsed, landing - roll ## Analysis THE PILOT VERIFIED THAT THE LANDING GEAR WAS DOWN AND LOCKED SEVERAL TIMES DURING THE APPROACH. AFTER A NORMAL LANDING, THE LANDING GEAR SUDDENLY COLLAPSED DURING ROLLOUT. AN EXAMINATION OF AIRPLANE REVEALED THAT THE ATTACHMENT RIVETS OF THE LANDING GEAR TRANSMISSION HAD FAILED DUE TO UNDETERMINED REASONS, AND THE TRANSMISSION HAD COMPLETELY SEPARATED FROM THE ATTACH BRACKET. SOME OF THE RIVETS WERE SHEARED OUT PREVIOUS TO THE ACCIDENT FLIGHT. ## Factual narrative On August 13, 1994, about 1845 Pacific daylight time, N5063P, a Piper PA-24-180, operated by the owner/pilot, sustained substantial damage after the landing gear collapsed during landing rollout in Nehalem, Oregon. The private pilot and his three passengers were not injured. Visual meteorological conditions prevailed and a flight plan was not filed. The personal flight departed Vancouver, Washington, and was conducted under 14 CFR 91. According to an FAA Aviation Safety Inspector from Hillsboro, Oregon, the pilot stated that he confirmed the landing gear was down and locked during the final approach to runway 15 at the Nehalem Airport. This was corroborated by passenger statements. After a normal touchdown, the airplane rolled out about 100 feet and the landing gear suddenly collapsed, causing substantial damage to the belly of the fuselage. According to the FAA inspector, the main landing gear transmission mounting rivets appeared to have partially separated prior to the landing. After an examination of the separation, the inspector reported the following: The landing gear transmission was pulled out of it's attachment bulkhead between the front seats and under the floorboards. Further inspection reveals that , of the five (5) rivets attaching the transmission mount bracket on each side, (4) had been sheared on the right side and (1) on the left side at some time previously. This was evident by the aluminum oxides present on the ends of the sheared rivets, as opposed to the freshly sheared look of the remaining rivets. It is my opinion that the previously sheared rivets had been cut for some time since there was considerable black metal oxide surrounding each rivet. The aluminum sheet metal bulkhead, separating the transmission from the bracket, appeared to have been recently ripped out. This is to be expected since it was never designed to support the total loads imposed by the landing gear system. The FAA inspector also reported: The maintenance records show that immediately previous to the flight.... the mechanic also adjusted the landing gear down locks.... [The mechanic] stated that he had found the left main landing gear downlock to be excessively tight. He rerigged the downlock to factory specs and retracted the gear three times so that he could recheck the downlock rigging. He found it unchanged and the dimensions OK. The aircraft flew and additional (2) flights with (3) landings prior to it's flight to Nehalem Bay Airport. [The mechanic] feels that the excessive loads imposed on the transmission mounts by the left gear cable could have led to the shearing of the mount rivets. He noted that he has never seen this before, but, recently, the International Comanche Society has advised owners to increase the tension on the downlock for added safety. [The mechanic] disagrees with this advice since it is contrary to the manufacturer's instructions. ## Aircraft - Registration: [N5063P](https://openairdocs.org/deregistered/N5063P-1998-04-13), registration cancelled 1998-04-13, S/N 2469 (OpenAirDocs) - Reported make and model: PIPER PA-24-180 - Registry model: [Piper PA-24](https://openairdocs.org/model/piper-pa-24) (registry code 7102402) (OpenAirDocs) - Category: Airplane - Serial number: 24-69 - Airframe hours: 6520 - Engines: LYCOMING O-360-A1A 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Mcpartland, James R. - Registered owner: Mcpartland, James R. - Airworthiness certificate: Special, Provisional (Special); Standard, Normal - Last inspection: Annual, October 15, 1993, 59 hours before - Departed: 60S, VANCOUVER, WA - Airport: 3S7, Nehalem Bay State, runway 15, 2,350 × 50 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 49; private; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 963 total, 64 in this make and model, 5 in the last 90 days, 2 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 290° at 11 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 66 °F, dew point 57 °F - Altimeter: 30.00 inHg - Observed at: AST, 25 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 (OpenAirDocs). - [Accident 19940813027109A](https://openairdocs.org/incident/19940813027109A), Aug 13, 1994: Piper PA24180, Manzanita, OR, Substantial damage. Landing gear collapsed on landing. Prior overstress landings had sheared transmission attach bolts. Failed bulkhead From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.