# NTSB SEA98LA073: Aero Commander 500-A, N9382R, Billings, MT, May 9, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 9, 1998, 11:05 local (17:05 UTC) - Place: Billings, MT - Location: 45.8078° N, 108.5435° W: Placed by OpenAirDocs at BILLINGS LOGAN INTL (BIL), within about a mile (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=45.8078&lon=-108.5435&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report February 15, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 42784 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA98LA073 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42784/pdf - Page: https://openairdocs.org/ntsb/SEA98LA073 ## Probable cause Failure of the main landing gear strut outer-body to inner-body needle bearing from the lack of lubrication and the development of corrosion. An inadequate manufacturer's inspection program was a factor. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, takeoff - initial climb - landing gear,main gear - corroded (cause) - maintenance,lubrication - not performed, company maintenance personnel (cause) - maintenance,aaip/progressive program - inadequate, manufacturer (contributing factor) - Gear collapsed, landing - roll ## Analysis The pilot reported that, after takeoff, the left-main landing gear would not fully retract. The pilot stated that he then extended the landing gear and performed various emergency procedures in an attempt to fully extend the left-main. The pilot was unable to get the left-main to lock in the down position and elected to land the airplane with the right-main and nosewheel extended. During the landing roll, the left-main gear collapsed and the airplane slid to a stop. Inspection of the left-main landing gear revealed that the upper-main landing gear strut's outer-body to inner-body needle bearing had failed, and the lower needle bearing was near failure. The lack of lubrication in this area was noted, along with evidence of severe corrosion development. The Manufacturer's Inspection Program for this model aircraft does not address a calendar and/or time inspection interval, or lubrication interval for the upper and lower needle bearing. ## Factual narrative On May 9, 1998, at 1105 mountain daylight time, an Aero Commander 500-A, N9382R, registered to and operated by Corporate Air as a 14 CFR Part 91 positioning flight, landed at the Billings Airport, Billings, Montana, with the left-main gear in the unlocked position. The left main gear collapsed during the landing roll. Visual meteorological conditions prevailed at the time and an instrument flight rules flight plan was filed. The aircraft was substantially damaged and the commercial pilot, the sole occupant, was not injured. The flight had departed Billings at 0810, and was destined for Minot, North Dakota. The pilot reported that after takeoff from Billings, the left-main landing gear would not fully retract. The pilot extend the landing gear and performed various emergency procedures for about three hours in an attempt to fully extend the left-main. The pilot was unable to get a down-and-locked indication on the left-main gear and elected to land the airplane with the right-main and nosewheel extended. During the landing roll, the left-main landing gear collapsed and the airplane slid down the runway. Inspection of the left-main landing gear by an inspector from the Federal Aviation Administration Flight Standards District Office, Helena, Montana, revealed that the upper-main landing gear strut's outer-body to inner-body needle bearing had failed and the lower needle bearing was near failure. The lack of lubrication in this area was noted, along with evidence of severe corrosion development. The right-main landing gear was also inspected, and during the disassembly, similar conditions existed for the right gear as was found for the left. The Manufacturer's Inspection Program for the 500 series aircraft does not address a calendar and/or time inspection interval, or lubrication interval for the upper and lower needle bearings. The manufacturer's inspection program maintenance manuals for the 600 and 700 series aircraft, which have the same design landing gear assemblies, identify procedures to overhaul and lubricate the landing gear at a five year or three thousand hour interval. ## Aircraft - Registration: [N9382R](https://openairdocs.org/deregistered/N9382R-2003-07-21), registration cancelled 2003-07-21, S/N 500A-899-8, built 1960 (OpenAirDocs) - Reported make and model: Aero Commander 500-A - Registry model: [Aero Commander 500-B](https://openairdocs.org/model/aero-commander-500-b) (registry code 0141106) (OpenAirDocs) - Registry engine: [Lycoming IGSO-540-B1A](https://openairdocs.org/engine/lycoming-igso-540-b1a) (registry code 41535, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 500A-899-8 - Airframe hours: 15233 - Engines: Lycoming IO-540-E1A5 290 horsepower reciprocating - Damage: Substantial damage - Flight: Positioning, Part 91 - Registered owner: Corporate Air - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, April 19, 1998, 30 hours before - Destination: MOT, MINOT, ND - Flight plan: IFR - Airport: BIL, Billings, runway 28R, 10,528 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 32; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 1,420 total, 215 in this make and model, 700 as pilot in command, 180 in the last 90 days, 60 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 310° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: 3,000 ft broken - Temperature: 46 °F, dew point 39 °F - Altimeter: 29.00 inHg - Observed at: BIL ## 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 19980509015569A](https://openairdocs.org/incident/19980509015569A), May 9, 1998: Gulstm 500A, Billings, MT, Substantial damage. (-23) Left main landing gear would not extend or retract. Upon landing, left gear collapsed with resulting damage to underside of aircraft. The cause of… 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.