# NTSB LAX95LA073: Cessna 421C, N746CA, Chinle, AZ, December 14, 1994 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: December 14, 1994, 16:30 local (23:30 UTC) - Place: Chinle, AZ - Coordinates: 36.229972, -109.56916 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.2300&lon=-109.5692&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 5 uninjured - Status: Completed, report August 31, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 29010 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX95LA073 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/29010/pdf - Page: https://openairdocs.org/ntsb/LAX95LA073 ## Probable cause the overload failure of the nose gear trunion for undetermined reasons. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Gear collapsed, landing - roll - landing gear,nose gear attach point - overload (cause) - landing gear,nose gear attach point - failure,total (cause) ## Analysis THE COMPANY DID NOT REPORT THE ACCIDENT TO EITHER THE FAA OR SAFETY BOARD. AN FAA AIRWORTHINESS INSPECTOR FOUND THE DAMAGED AIRPLANE IN A HANGAR AT THE COMPANY BASE. THE PILOT AND A COMPANY MECHANIC ONBOARD THE AIRCRAFT DURING THE ACCIDENT SUBMITTED WRITTEN STATEMENTS. THE AIRCRAFT WAS ON A POSITIONING FLIGHT TO PICK UP A MEDICAL EVACUATION PATIENT AT A DIRT AIRSTRIP. BOTH THE PILOT AND MECHANIC SAID THE APPROACH AND TOUCHDOWN ON THE DIRT AIRSTRIP WERE NORMAL. THE MECHANIC SAID HE SAW THREE DOWN AND LOCKED GEAR LIGHTS BEFORE LANDING. AFTER TOUCHDOWN ON THE MAINS, THE NOSE OF THE AIRCRAFT SETTLED DOWN PAST THE NORMAL NOSE GEAR CONTACT POINT. THE MECHANIC SAID THE AIRCRAFT NOSE THEN WENT TO THE RIGHT AND THE AIRCRAFT BEGAN TO SLIDE SIDEWAYS. THE AIRCRAFT VEERED OFF THE RUNWAY TO THE RIGHT AND HIT A BARBED WIRE FENCE. NEITHER THE PILOT NOR THE MECHANIC REPORTED ANY UNUSUAL 'NOISES OR SENSATIONS' FROM THE NOSE GEAR DURING THE LANDING. BOTH THE PILOT AND MECHANIC STATED THAT THE LANDING GEAR TRACKS WERE STRAIGHT ON THE RUNWAY UNTIL THE NOSE GEAR 'DUG IN AND VEERED TO THE RIGHT.' THE FAA INSPECTOR SAID THE NOSE GEAR FAILED TO THE LEFT WITH EVIDENCE OF A SIDE LOAD. THE UPPER RIGHT TRUNION FRACTURED FROM THE NOSE GEAR CASTING, AND THE FRACTURE FACE APPEARED TO BE INSTANTANEOUS OVERLOAD, WITH NO EVIDENCE OF PRE-EXISTING CRACKS OR FLAWS. ## Factual narrative On December 14, 1994, about 1630 mountain standard time, a Cessna 421C, N746CA, sustained substantial damage following the collapse of the nose and left main landing gear at the Chinle, Arizona, airstrip. The aircraft was owned and operated by Critical Air Medicine, Inc., of San Diego, California, and was on a 14 CFR Part 91 positioning flight to pick up a discretionary medical evacuation patient. Visual meteorological conditions prevailed and no flight plan was filed. The aircraft sustained substantial damage. The certificated airline transport pilot and the four medical crew members were not injured. The flight originated at Tuba City, Arizona, on the day of the accident at 1530. The accident was reported to the National Transportation Safety Board by a Federal Aviation Administration (FAA) airworthiness inspector from the San Diego Flight Standards District Office on January 3, 1995, after he discovered the damaged airplane in a hangar at the company base. The company did not complete a Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), despite three separate requests. The pilot and a company mechanic onboard the aircraft at the time of the accident submitted explanatory letters to the FAA inspectors. According to both the pilot and mechanic, the approach and touchdown on the dirt airstrip were normal. The mechanic said he observed three down and locked gear indicator lights prior to touchdown. After touchdown on the main landing gear, the nose of the aircraft settled down past the normal nose gear contact point. The mechanic said that at that point, the aircraft nose went to the right and the aircraft began to slide sideways. The aircraft veered off the runway to the right and hit a barbed wire fence. Neither the pilot nor the mechanic reported any unusual "noises or sensations" from the nose gear during the landing. Both the pilot and mechanic stated that the landing gear tracks were straight on the runway until the nose gear "dug in and veered to the right." The FAA inspector who discovered the damage to the aircraft reported that the nose gear failed to the left with evidence of a side load. The upper right trunion fractured from the nose gear casting. According to the inspector, the fracture face appeared to be instantaneous overload, with no evidence of pre-existing cracks or flaws. ## Aircraft - Registration: N746CA (not matched to a registry record) - Reported make and model: CESSNA 421C - Category: Airplane - Serial number: 421C1049 - Airframe hours: 4022 - Engines: CONTINENTAL GTSIO-520N 375 horsepower reciprocating - Damage: Substantial damage - Flight: Positioning, Part 91 - Registered owner: Critical Air Medicine, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, September 30, 1994, 91 hours before - Departed: T03, TUBA CITY, AZ - Destination: Q32 - Airport: Q32, Chinle Airstrip, runway 35, 4,200 × 60 ft, dirt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 32; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 3,000 total ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 20 statute miles ## 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 19941214044019A](https://openairdocs.org/incident/19941214044019A), Dec 14, 1994: Cessna 421C, Chinle, AZ, Substantial damage. Nose and right main collapsed on landing roll. Veered into fence. Side loading. Fractured trunnion. EMS ferry flite 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.