# NTSB FTW97IA119: Boeing 727-2K5, N909PG, Dfw Airport, TX, March 10, 1997 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: March 10, 1997, 13:21 local (19:21 UTC) - Place: Dfw Airport, TX - Location: 32.8972° N, 97.0377° W: Placed by OpenAirDocs at DALLAS-FORT WORTH INTL (DFW), within about a mile (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=32.8972&lon=-97.0377&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report April 24, 1998 - Report: Approved by Office Director - NTSB case key (mKey): 20064 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW97IA119 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/20064/pdf - Page: https://openairdocs.org/ntsb/FTW97IA119 ## Probable cause failure of the outer bearing for undetermined reason(s). ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, takeoff - roll/run - landing gear,axle - undetermined (cause) - landing gear,axle - failure,total (cause) - landing gear,axle - separation - miscellaneous,bolt/nut/fastener/clamp/spring - fractured - landing gear,axle - overtemperature ## Analysis The right hand inboard main landing gear wheel assembly departed the aircraft during the takeoff roll. The crew returned the aircraft to the departure airport and the flight landed without further incident. Visual examination revealed that the outer cone-bearing seized. The bearing race, retainer ring, and axle were damaged and the inner ring of the outer wheel bearing exhibited deformation, rubbing, cracking, and galling. None of the bearing rollers were recovered. Metallurgical examination disclosed that the inner wheel bearing migrated approximately 1.5 inches in the inboard direction. The outer bearing ring showed rub damage on the circumference of the inner and outer diameter and the bearing cage. The bolt that locked the wheel retaining nut was fractured; however, it could not be determined if the fracture of the bolt contributed to or was the result of the bearing damage. The inner ring of the outer wheel bearing displayed heat damage and localized melting. The damage of the inner ring 'appeared to be more consistent with bearing deterioration caused by inadequate or loss of preloading rather than a bearing seizure event.' ## Factual narrative On March 10, 1997, at 1321 central standard time, a Boeing 727-2K5, N909PG, registered to Pegasus at San Francisco, California, operated by Aeromexpress as a Title 14 CFR Part 129 on demand cargo flight, experienced the separation of the number 3 main landing gear wheel during the takeoff at Dallas/Fort Worth International Airport, DFW Airport, Texas. Visual meteorological conditions prevailed and an instrument flight plan was filed. The 4 crew members were not injured and the airplane sustained minor damage. Air Traffic Control personnel reported that the flight departed runway 35R with a planned destination of Mexico City, Mexico. During the departure climb, ATC personnel informed the crew that a wheel assembly had departed the aircraft. The crew reported to ATC that all cockpit indications were normal and they would return to the DFW Airport for landing. The flight landed on runway 35L without further incident. Aeromexpress has operated the aircraft since July 1994, under an approved foreign air carrier aircraft maintenance program for 6,783:30 hours with 2,709 cycles. The last installation of the wheel and brake was accomplished on February 10, 1997. Total aircraft time was 40,423.07 hours with 17,036 cycles at the time of the wheel separation. Inspection of the wheel by the FAA inspector and the investigator-in-charge revealed that the outer bearing race, retainer ring, and axle were damaged and the inner ring of the outer wheel bearing exhibited deformation, rubbing, cracking, and galling. None of the bearing rollers were recovered. Metallurgical examination at Boeing disclosed that the inner wheel bearing of the right hand inboard main landing gear wheel assembly migrated approximately 1.5 inches in the inboard direction. The outer bearing ring showed rub damage on the circumference of the inner and outer diameter and the bearing cage. The bolt that locked the wheel retaining nut was fractured; however, it could not be determined if the fracture of the bolt contributed to or was the result of the bearing damage. The inner ring of the outer wheel bearing displayed heat damage and localized melting. The damage of the inner ring "appeared to be more consistent with bearing deterioration caused by inadequate or loss of preloading rather than a bearing seizure event." See the enclosed report for details of the examination. ## Aircraft - Registration: [N909PG](https://openairdocs.org/aircraft/N909PG), registered now, S/N 21852, built 1979 (OpenAirDocs) - Reported make and model: Boeing 727-2K5 - Registry model: [Boeing 727-2K5](https://openairdocs.org/model/boeing-727-2k5) (registry code 138004P) (OpenAirDocs) - Registry engine: [Pratt & Whitney JT8D series](https://openairdocs.org/engine/pratt-whitney-jt8d-series) (registry code 52053, turbo-jet) (OpenAirDocs) - Category: Airplane - Serial number: 21853 - Airframe hours: 40423 - Engines: P&W JT8D-17 16000 lbs thrust turbo fan - Damage: Minor damage - Flight: Part 129 - Operator: Aeromexpress - Registered owner: Pegasus - Airworthiness certificate: Standard, Transport - Last inspection: AAIP, March 17, 1907, 2,585 hours before - Departed: DFW - Destination: MEX, MEXICO CITY, OF - Flight plan: IFR - Airport: DFW, Dfw International, runway 36R, 11,387 × 200 ft, concrete ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 45; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 8,000 total, 3,727 in this make and model, 5,000 as pilot in command, 150 in the last 90 days, 50 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 20° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: 5,500 ft broken - Temperature: 59 °F, dew point 46 °F - Altimeter: 30.00 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 19970310007319I](https://openairdocs.org/incident/19970310007319I), Mar 10, 1997: Boeing 7272L5, Dallas-Ft Worth, TX, Minor damage. Narrative: on departure from Dallas/fort Worth international airport, aeromexpress flight 9501 lost the #3 main landing gear tire & wheel assy at approx 50'… 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.