# NTSB ANC01LA055: Cessna 170B, N3143A, Fairbanks, AK, May 8, 2001 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 7, 2001, 19:56 local (May 8, 2001, 03:56 UTC) - Place: Fairbanks, AK - Coordinates: 64.813613, -147.859725 - Nearby events: https://openairdocs.org/map.md?lat=64.8136&lon=-147.8597&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report February 20, 2002 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA-AL-FAI FSDO 01 - NTSB case key (mKey): 52229 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC01LA055 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/52229/pdf - Page: https://openairdocs.org/ntsb/ANC01LA055 ## Probable cause A failure of the tailwheel spring assembly due to fatigue during touch and go landings. A factor in the accident was an inadequate annual inspection by maintenance personnel. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, landing - flare/touchdown - landing gear,tailwheel assembly - fatigue (cause) - maintenance,annual inspection - inadequate, other maintenance personnel (contributing factor) ## Analysis The commercial certificated pilot/flight instructor was conducting a local area instructional flight with the student pilot/owner of the airplane. The flight instructor reported that he was doing wheel landings with the student to a gravel runway. During the touch down on the third or fourth landing, the tailwheel assembly suddenly broke off. An FAA airworthiness inspector examined the airplane after the accident and found a preexisting crack in the tailwheel spring assembly that was about 1/16 inch deep, and about 1/2 inch long. The spring failed at the crack. When the tail wheel departed the airplane, it struck the bottom of the rudder, and the rudder trim tab. The bottom and aft portion of the rudder assembly was torn open. The spring assembly had accrued 126 hours, and 65 hours since the last annual inspection. ## Factual narrative On May 7, 2001, at 1956 Alaska daylight time, a wheel-equipped Cessna 170B airplane, N3143A, sustained substantial damage during landing at the Fairbanks International Airport, Fairbanks, Alaska. The airplane was being operated as a visual flight rules (VFR) local area instructional flight when the accident occurred. The airplane was operated by the student pilot/owner. The commercial certificated pilot/flight instructor, and the student pilot, were not injured. Visual meteorological conditions prevailed. The flight originated at the Fairbanks International Airport at 1917. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on May 9, 2001, the flight instructor reported that he was seated in the right seat, and was conducting wheel landings with the student on the ski strip, runway 19, at Fairbanks. During the touchdown on the third or fourth landing, the tailwheel assembly suddenly broke off. A Federal Aviation Administration (FAA) airworthiness inspector, Fairbanks Flight Standards District Office (FSDO), examined the airplane after the accident. He reported he found a preexisting crack in the tailwheel spring assembly that was about 1/16 inch deep, and about 1/2 inch long. He said the spring failed at the crack, and when the tailwheel departed the airplane, it struck the bottom of the rudder, and the rudder trim tab. The bottom and aft portion of the rudder assembly was torn open. In the Pilot/Operator Report (NTSB form 6120.1/2) submitted by the student pilot/owner, the owner indicated the tailwheel spring had a total time of 162 hours. The 6120.1/2 report noted an annual inspection was conducted on November 6, 2000, 65 hours before the accident. ## Aircraft - Registration: [N3143A](https://openairdocs.org/aircraft/N3143A), registered now, S/N 25787, built 1953 (OpenAirDocs) - Reported make and model: Cessna 170B - Registry model: [Cessna 170B](https://openairdocs.org/model/cessna-170b) (registry code 2072306) (OpenAirDocs) - Registry engine: [Continental C145 series](https://openairdocs.org/engine/continental-c145-series) (registry code 17012, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 25787 - Airframe hours: 4904 - Engines: Continental C-145 145 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Cordell T. Gray - Airworthiness certificate: Standard, Normal - Last inspection: Annual, November 6, 2000, 65 hours before - Departed: PAFA, FAIRBANKS, AK - Airport: PAFA, Fairbanks International, runway 19, 3,980 × 75 ft, gravel ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 62; injuries: none; commercial, flight instructor; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; last flight review May 9, 2000; seat: right; flight hours: 4,591 total, 210 in this make and model, 3,891 as pilot in command, 56 in the last 90 days, 48 in the last 30 days, 6 in the last 24 hours - Student pilot; age 39; injuries: none; student; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 83 total, 83 in this make and model, 28 as pilot in command, 39 in the last 90 days, 17 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 184° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: 5,500 ft broken - Temperature: 45 °F, dew point 30 °F - Altimeter: 29.63 inHg - Observed at: PAFA ## 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 20010507007849A](https://openairdocs.org/incident/20010507007849A), May 7, 2001: Cessna 170B, Fairbanks, AK, No damage. (.19)On may 7, 2001, at 1956 Alaska daylight time, a wheel-equipped Cessna 170B airplane, N3143A, sustained substantial damage during landing at the Fairbanks… 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.