# NTSB CHI98LA210: Cessna 180A, N9753B, Bay City, MI, June 21, 1998 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: June 21, 1998, 11:45 local (15:45 UTC) - Place: Bay City, MI - Coordinates: 43.59024, -83.879524 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.5902&lon=-83.8795&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 2 minor - Status: Completed, report February 16, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 10924 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI98LA210 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/10924/pdf - Page: https://openairdocs.org/ntsb/CHI98LA210 ## Probable cause a fatigue failure of the left nose gear caster bolt which resulted in a separation of the nose gear during landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Main gear collapsed, landing - flare/touchdown - miscellaneous,bolt/nut/fastener/clamp/spring - fatigue (cause) - landing gear,nose gear assembly - separation - Nose over, landing - flare/touchdown ## Analysis The pilot reported that during the landing roll a 'rumbling noise' was heard and the airplane pulled slightly to the left when he applied the brakes. He stated he pulled back on the elevator to no avail, and the airplane nosed down and flipped inverted. Post accident inspection revealed the front wheel on the left float separated from the airplane. The wheel attachment bracket then dug into the sod airstrip which resulted in the airplane nosing over. Metallurgical examination revealed the left caster axis bolt failed due to a fatigue fracture. ## Factual narrative On June 21, 1998, at 1145 eastern daylight time, a float equipped Cessna 180A, N9753B, operated by an airline transport rated pilot, nosed over on landing at a private airstrip in Bay City, Michigan. The pilot and passenger received minor injuries. The airplane was substantially damaged. The 14 CFR Part 91 personal flight was operating in visual meteorological conditions without a flight plan. The flight originated from the private airstrip at 1115 edt. The pilot reported that during the landing roll a "rumbling noise" was heard and the airplane pulled slightly to the left when he applied the brakes. He stated he pulled back on the elevator to no avail, and the airplane nosed down and flipped inverted. Post accident inspection of the airplane by an inspector from the Federal Aviation Administration (FAA) Grand Rapids, Michigan, Flight Standards District Office (FSDO), revealed the front wheel on the left float separated from the airplane. He also reported the wheel attachment bracket then dug into the sod airstrip which resulted in the airplane nosing over. The left and right forward wheel casters and associated hardware were forwarded to the NTSB North Central Regional Office from the Inspector from the Grand Rapids FSDO. It was noted that the axis bolt on the left wheel caster was separated from the caster. These parts were then sent to the NTSB Metallurgical Laboratory, Washington, D.C., for inspection. The metallurgist who inspected the parts reported, "Examination disclosed that about 90 percent of the bolt [left caster] fracture was flat, smooth, and contained crack arrest positions indicative of fatigue crack propagation." "The SEM examination of the separated bolt pieces revealed that both origins of fatigue cracking in the bolt from the loft bow gear were located at small steps, apparently created during machining of the transition radius between the thicker head and the thinner median portions of the bolt." See attached Materials Laboratory Factual Report for further details. ## Aircraft - Registration: [N9753B](https://openairdocs.org/deregistered/N9753B-2001-05-09), registration cancelled 2001-05-09, S/N 50051 (OpenAirDocs) - Reported make and model: Cessna 180A - Registry model: [Cessna 180A](https://openairdocs.org/model/cessna-180a) (registry code 2072604) (OpenAirDocs) - Category: Airplane - Serial number: 50051 - Airframe hours: 2249 - Engines: Continental O-470-K 230 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Alan W. Hayward - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 24, 1998, 10 hours before - Departed: PVT - Airport: PVT, Hayward Field, runway 9, 2,275 × 75 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 46; airline transport; airplane ratings: multi-engine land, single-engine land, single-engine sea; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 12,000 total, 500 in this make and model, 7,000 as pilot in command, 240 in the last 90 days, 80 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 135° at 8 knots - Visibility: 15 statute miles - Lowest ceiling: none - Temperature: 81 °F - Altimeter: 29.00 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). - [Accident 19980621014509A](https://openairdocs.org/incident/19980621014509A), Jun 21, 1998: Cessna 180A, Bay City, MI, Substantial damage. Acft landing gear collapsed on landing, acft flipped over in a field, Bay City, MI. (.4)the pilot reported that during the landing roll a 'rumbling noise' was… 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.