# NTSB FTW99LA145: Bellanca 8KCAB, N5500C, Lufkin, TX, May 21, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 21, 1999, 14:00 local (19:00 UTC) - Place: Lufkin, TX - Location: 31.2340° N, 94.7500° W: Placed by OpenAirDocs at ANGELINA COUNTY (LFK), within about a mile (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=31.2340&lon=-94.7500&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report August 3, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 46338 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW99LA145 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46338/pdf - Page: https://openairdocs.org/ntsb/FTW99LA145 ## Probable cause The loss of control due to the separation of the left main landing gear as a result of the fatigue failure of the U-bolt which attaches the landing gear to the airframe. ## 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,main gear attachment - fatigue (cause) - landing gear,main gear - separation (cause) - Loss of control - on ground/water, landing - roll - aircraft control - not possible, pilot in command ## Analysis The left main landing gear separated from the airframe following a normal wheel landing on runway 15. The separation resulted from failure of the 'U-bolt' attaching the left main landing gear to the fuselage. The left wing contacted the ground and the airplane came to rest on the west side of the 4,550 foot runway. A review of the maintenance history of the airplane revealed that the airframe had accumulated a total time of 708 hours. The failed landing gear U-bolt, part number 1-9805, was shipped to the NTSB Materials Laboratories in Washington, D.C., for metallurgical evaluation. The metallurgical evaluation revealed that the bolt failed as a result of fatigue. ## Factual narrative On May 21, 1999, at 1400 central daylight time, a Bellanca 8KCAB tailwheel equipped airplane, N5500C, was substantially damaged following a loss of directional control while landing near Lufkin, Texas. The flight instructor and the instrument rated private pilot receiving instruction were not injured. The airplane was owned and operated by Nacogdoches Taildraggers, Inc., of Nacogdoches, Texas. Visual meteorological conditions prevailed for the Title 14 CFR Part 91 flight for which a flight plan was not filed. The local instructional flight originated from the A.L. Mangham, Jr. Regional Airport (OCH), near Nacogdoches, Texas, at approximately 1330. According to the FAA inspector who responded to the accident site, the flight arrived at the Angelina County Airport (LFK), located near Lufkin, Texas, to practice takeoffs and landings. The flight instructor reported that following their second practice landing, a normal wheel landing on runway 15, the "U-bolt" attaching the left main landing gear to the fuselage failed, resulting in the separation of the left main landing gear. The left wing contacted the ground and the airplane came to rest on the west side of the 4,550 foot runway. Examination of the 1978 model aircraft revealed structural damage to the left wing and the left main landing gear attaching point. Additionally, one propeller blade was bent and the underside of the airframe was damaged. A review of the maintenance history of the airplane by the FAA inspector revealed that the airframe had accumulated a total time of 708 hours. The failed landing gear U-bolt, Bellanca part number 1-9805, was shipped to the NTSB Materials Laboratories in Washington, D.C., for examination and evaluation. The metallurgical examination revealed that the bolt fractured as a result of fatigue. See enclosed report for details of the examination. The surface winds at the time of the occurrence were reported from 200 degrees at 5 knots. ## Aircraft - Registration: [N5500C](https://openairdocs.org/aircraft/N5500C), registered now, S/N 401-78, built 1978 (OpenAirDocs) - Reported make and model: Bellanca 8KCAB - Registry model: [Bellanca 8KCAB](https://openairdocs.org/model/bellanca-8kcab) (registry code 1220801) (OpenAirDocs) - Registry engine: [Lycoming IO-320 series](https://openairdocs.org/engine/lycoming-io-320-series) (registry code 41509, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 401-78 - Airframe hours: 708 - Engines: Lycoming AEIO-320-E2B 160 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Michael R. Mclean - Airworthiness certificate: Standard, Aerobatic; Standard, Normal - Last inspection: Annual, May 3, 1998, 106 hours before - Departed: OCH, NACOGDOCHES, TX - Airport: LFK, Angelina County Airport, runway 15, 4,515 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 78; commercial, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: right; flight hours: 7,578 total, 12 in this make and model, 7,251 as pilot in command, 91 in the last 90 days, 32 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 86 °F, dew point 68 °F - Altimeter: 30.00 inHg - Observed at: LFK, 1 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 19990521021709A](https://openairdocs.org/incident/19990521021709A), May 21, 1999: Bbavia 8KCAB, Lufkin, TX, Substantial damage. On may 21, 1999, at 1400 central daylight time, a Bellanca 8KCAB, tailwheel equipped airplane, N5500C, was substantially damaged following a loss of direction… ## Other investigations on N5500C (1) 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. - [NTSB ATL83LA323](https://openairdocs.org/ntsb/ATL83LA323), Aug 12, 1983: Bellanca 8-KCAB-150 (N5500C), Kennesaw, GA, substantial damage 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.