# NTSB SEA08LA029: Piper PA-44-180, N274ER, Byron, CA, November 14, 2007 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: November 14, 2007, 13:45 local (21:45 UTC) - Place: Byron, CA - Coordinates: 37.828609, -121.625831 - Nearby events: https://openairdocs.org/map.md?lat=37.8286&lon=-121.6258&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report March 31, 2008 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 67125 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA08LA029 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/67125/pdf - Page: https://openairdocs.org/ntsb/SEA08LA029 ## Probable cause The failure of the right main landing gear aft trunnion attach fitting due to overload during the landing roll. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Main gear collapsed, landing - roll - landing gear,normal retraction/extension assembly - overload (cause) - landing gear,normal retraction/extension assembly - fractured (cause) - On ground/water encounter with terrain/water, landing - roll - terrain condition - runway ## Analysis After touchdown during the landing roll, the flight instructor heard a "clunking" sound, followed by the airplane dropping slightly to the right. The flight instructor subsequently heard a second "clunk" as the airplane's right wing dropped to the runway. A post-accident examination revealed that the right main landing gear aft trunnion attach fitting had failed. A subsequent metallurgical examination revealed that although a fatigue region was identified on one of the 3 fracture surfaces, it was relatively small, and that the attach fitting most likely failed due to overload. ## Factual narrative On November 14, 2007, about 1345 Pacific standard time, a Piper PA-44-180, N274ER, sustained substantial damage following a right main landing gear collapse and a loss of control during landing roll at the Byron Airport (C83), Byron, California. The flight instructor, pilot-rated student and sole passenger were not injured. Visual meteorological conditions prevailed for the 14 CFR Part 91 instructional flight, and a flight plan was not filed. The flight departed the Hayward Executive Airport (HWD), Hayward, California, about 1200. In a statement dated November 27, 2007, the flight instructor reported that this was to be the fourth full stop landing with his student. The flight instructor stated that at the midfield point he verified that the landing gear was down by observing the 3 green landing gear down-and-locked lights illuminated. The flight instructor further stated the after touching down on the centerline and during the rollout, and after about 300 to 400 feet, "...I felt a 'clunking' sound, and the airplane dropped slightly to the right and started to pull to the right. I would estimate we were rolling 50 to 60 knots at this point." The flight instructor further reported that he then brought both throttles to idle and helped on the controls with the student to maintain directional control. The pilot stated, "Soon after there was a second 'clunk' and the right wing dropped to the runway, resulting in an uncontrollable slide off the right side of the runway." Examination of the airplane by a Federal Aviation Administration inspector revealed that the right main landing gear trunnion had failed. The component was forwarded to the Safety Board's materials laboratory for further examination. The examination revealed that the right main landing gear aft trunnion attach fitting (p/n 67042-13) was fractured at 3 locations intersecting the center bearing boss area. The outboard, forward and lower fracture surfaces each exhibited a rough and irregular appearance consistent with overstress in a cast aluminum alloy. It was also noted that a portion of the outboard fracture had a relatively flat plane of fracture with a curving boundary, features consistent with fatigue. ## Aircraft - Registration: [N274ER](https://openairdocs.org/aircraft/N274ER), registered now, S/N 44-7995083, built 1978 (OpenAirDocs) - Reported make and model: Piper PA-44-180 - Registry model: [Piper PA-44-180](https://openairdocs.org/model/piper-pa-44-180) (registry code 7104402) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 44-7995083 - Airframe hours: 13027.2 - Engines: Lycoming O-360 180 horsepower reciprocating; Lycoming O-360 180 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Flying Vikings - Airworthiness certificate: Standard, Normal - Last inspection: Annual, October 1, 2007, 85.1 hours before - Departed: HWD, Hayward, CA - Destination: C83, Byron, CA - Airport: C83, Byron Airport, runway 30, 4,500 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 32; injuries: none; commercial, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; seat: right; flight hours: 2,400 total, 170 in this make and model, 2,301 as pilot in command, 169 in the last 90 days, 40 in the last 30 days, 2 in the last 24 hours - Student pilot; age 20; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 1; seat: left; flight hours: 239 total, 14 in this make and model, 157 as pilot in command, 103 in the last 90 days, 21 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 330° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 73 °F, dew point 52 °F - Altimeter: 30.02 inHg - Observed at: SCK, 21 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 20071114827039A](https://openairdocs.org/incident/20071114827039A), Nov 14, 2007: Piper PA44180, Byron, CA, Substantial damage. (-23) The main landing gear trunnions showed signs of improper maintenance. No new grease was in the trunnion bushings, maintenance did not follow proper… 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.