# NTSB CHI02IA270: Fokker 100, N1473K, Minneapolis, MN, September 5, 2002 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: September 5, 2002, 06:40 local (11:40 UTC) - Place: Minneapolis, MN - Coordinates: 44.880001, -93.216667 - Nearby events: https://openairdocs.org/map.md?lat=44.8800&lon=-93.2167&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 33 uninjured - Status: Completed, report September 30, 2003 - Report: Approved by Office Director - Parties: American Airlines, FAA - Minneapolis FSDO - NTSB case key (mKey): 55802 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI02IA270 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/55802/pdf - Page: https://openairdocs.org/ntsb/CHI02IA270 ## Probable cause The improper installation of the #2 main landing gear wheel, including the axle nut not being properly torqued and safetied, which resulted in the wheel separation during takeoff. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, takeoff - landing gear,wheel - separation (cause) - maintenance,service of aircraft/equipment - improper, company maintenance personnel (cause) - miscellaneous,bolt/nut/fastener/clamp/spring - undertorqued (cause) - miscellaneous,bolt/nut/fastener/clamp/spring - not safetied (cause) ## Analysis During takeoff the #2 wheel separated from the left main landing gear assembly. A company mechanic stated that during a walk-around inspection he noted the #1 and #2 main landing gear tires needed to be replaced. The #1 & #2 tires are on the left main landing gear assembly; with the #1 tire being outboard of the #2 tire. The mechanic reported, "We removed & replaced #2 main landing gear [tire], with nothing unusual during the tire change." The axle nut/spacer assembly was found with the wheel. The axle nut lock-bolts were found installed in the axle nut/spacer assembly with safety wire connecting the lock-bolts to the axle nut. The lock-bolts were not damaged. The interfacing threads between the axle nut/spacer assembly and the axle were not stripped and the treads were not worn. A demonstration of a wheel installation and a review of the installation procedures were performed at the request of the NTSB. In order for the lock-bolts to engage the axle keyslot, the axle nut/spacer assembly had to be properly torqued and wheel bearings seated. ## Factual narrative On September 5, 2002, at 0640 central daylight time, a Fokker 100, N1473K, operated by American Airlines, Fort Worth, Texas, sustained minor damage when the number two main landing gear wheel separated from the axle during takeoff from Minneapolis-St. Paul International Airport (MSP), Minneapolis, Minnesota. Visual meteorological conditions prevailed at the time of the incident. The scheduled passenger flight was operating under the provisions of 14 CFR Part 121 on an instrument flight rules (IFR) flight plan. The flightcrew and passengers reported no injuries. The flight made an uneventful landing at Chicago O'Hare International Airport (ORD) at 0735. A company mechanic stated that during a walk-around inspection he noted the #1 and #2 main landing gear tires needed to be replaced. The #1 & #2 tires are on the left main landing gear assembly; with the #1 tire being outboard of the #2 tire. The mechanic reported, "We removed & replaced #2 main landing gear [tire], with nothing unusual during the tire change." The mechanic stated the #1 main landing gear tire was then replaced and "nothing unusual" was encountered during that tire change. During takeoff the #2 wheel separated from the left main landing gear assembly and was found near the end of runway 12L. The axle nut/spacer assembly was found with the wheel. The axle nut lock-bolts were found installed in the axle nut/spacer assembly with safety wire connecting the lock-bolts to the axle nut. The lock-bolts were not damaged. The interfacing threads between the axle nut/spacer assembly and the axle were not stripped and the treads were not worn. A demonstration of a wheel installation and a review of the installation procedures were performed at the request of the NTSB. In order for the lock-bolts to engage the axle keyslot, the axle nut/spacer assembly had to be properly torqued and wheel bearings seated. ## Aircraft - Registration: [N1473K](https://openairdocs.org/deregistered/N1473K-2004-06-04), registration cancelled 2004-06-04, S/N 11515, built 1994 (OpenAirDocs) - Reported make and model: Fokker 100 - Registry model: [Fokker F.28 MK 0100](https://openairdocs.org/model/fokker-f-28-mk-0100) (registry code 4990807) (OpenAirDocs) - Registry engine: [Rolls-Royce TAY-650-15](https://openairdocs.org/engine/rolls-royce-tay-650-15) (registry code 54557, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 11515 - Airframe hours: 20571.4 - Engines: Rolls-Royce 850-15 15000 lbs thrust turbo fan; Rolls-Royce 850-15 15000 lbs thrust turbo fan - Damage: Minor damage - Flight: Part 121 - Registered owner: American Airlines - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, September 5, 2002, 28.83 hours before - Departed: MSP, Minneapolis, MN - Destination: ORD, Chicago, IL - Flight plan: IFR - Airport: MSP, Minneapolis-St. Paul Intl, runway 12L, 8,200 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 43; injuries: none; commercial, flight instructor, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 1,425 in this make and model - Co-pilot; age 39; injuries: none; airline transport, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: right; flight hours: 236 in this make and model ## Weather - Conditions: Visual (VMC), Dawn - Wind: 150° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 63 °F, dew point 54 °F - Altimeter: 30.10 inHg ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Incident 20020905029409I](https://openairdocs.org/incident/20020905029409I), Sep 5, 2002: Fokker F28MK0100, Chicago, IL, Minor damage. (-23) On Thursday September 05, 2002 an inspector from the o'Hare flight standards district office (FSDO) received a telephone call from the amrcmo pmi terry… 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.