# NTSB ERA09CA006: Beech F17D, N18555, Moscow, TN, October 3, 2008 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: October 3, 2008, 12:15 local (17:15 UTC) - Place: Moscow, TN - Coordinates: 35.118331, -89.367774 - Nearby events: https://openairdocs.org/map.md?lat=35.1183&lon=-89.3678&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report January 22, 2009 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 69236 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA09CA006 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/69236/pdf - Page: https://openairdocs.org/ntsb/ERA09CA006 ## Probable cause The mechanical failure of the landing gear actuation chain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: gear extension and retract sys](https://openairdocs.org/ntsb-findings/01023230): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Beech F17D, 1 case](https://openairdocs.org/ntsb-findings/01023230/cases.md?model=1150558), [All aircraft, 416 cases](https://openairdocs.org/ntsb-findings/01023230/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094) (defining event); cases with it: [Beech F17D, 1 case](https://openairdocs.org/ntsb-events/094/sequence.md?model=1150558), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis According to the pilot/owner of the Beech F17D Staggerwing biplane, on the day of the accident, he took a passenger on a brief local flight, and then they returned for some landings and takeoffs. The winds were calm, and the first landing was uneventful. The pilot took off again, circuited the traffic pattern, and landed a second time. Shortly after touchdown, the airplane began to "sink." The pilot tried to raise the nose to offload the landing gear, and he shut down the engine, while the airplane continued to settle. The propeller struck the ground, and the airplane settled on the right lower wing before it came to a stop. The aft fuselage, propeller, lower cowl and outboard spar of the right lower wing were damaged. Postaccident examination indicated that the chain used to retract and extend the right main landing gear had fractured, which resulted in the partial retraction of the landing gear. According to maintenance records, the chain was installed new in the airplane in 1969, and it had accumulated approximately 910 hours in service. The pilot/owner estimated that the chain had accumulated 1,800 cycles, with each cycle consisting of one retraction and one extension. Visual examination revealed 29 fractures in the outer chain plates, and two completely fractured outer plates, not including the chain failure point. All fractures were oriented radially with respect to the link pivots. Every outer plate was stamped with the notation "ACME 40 SINGAPORE." The National Transportation Safety Board was unable to determine whether this failure mode was limited to this make and model chain. The airplane was manufactured in 1937, and the manufacturer had not established any time or cycle life limits for the chain. ## Factual narrative According to the pilot/owner of the Beech F17D Staggerwing biplane, on the day of the accident, he took a passenger on a brief local flight, and then they returned for some landings and takeoffs. The winds were calm, and the first landing was uneventful. The pilot took off again, circuited the traffic pattern, and landed a second time. Shortly after touchdown, the airplane began to "sink." The pilot tried to raise the nose to offload the landing gear, and he shut down the engine, while the airplane continued to settle. The propeller struck the ground, and the airplane settled on the right lower wing before it came to a stop. The aft fuselage, propeller, lower cowl and outboard spar of the right lower wing were damaged. Postaccident examination indicated that the chain used to retract and extend the right main landing gear had fractured, which resulted in the partial retraction of the landing gear. According to maintenance records, the chain was installed new in the airplane in 1969, and it had accumulated approximately 910 hours in service. The pilot/owner estimated that the chain had accumulated 1,800 cycles, with each cycle consisting of one retraction and one extension. Visual examination revealed 29 fractures in the outer chain plates, and two completely fractured outer plates, not including the chain failure point. All fractures were oriented radially with respect to the link pivots. Every outer plate was stamped with the notation "ACME 40 SINGAPORE." The National Transportation Safety Board was unable to determine whether this failure mode was limited to this make and model chain. The airplane was manufactured in 1937, and the manufacturer had not established any time or cycle life limits for the chain. ## Aircraft - Registration: [N18555](https://openairdocs.org/aircraft/N18555), registered now, S/N 157, built 1937 (OpenAirDocs) - Reported make and model: BEECH F17D - Registry model: [Beech F17D](https://openairdocs.org/model/beech-f17d) (registry code 1150558) (OpenAirDocs) - Registry engine: [Jacobs L6](https://openairdocs.org/engine/jacobs-l6) (registry code 35005, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 157 - Airframe hours: 2922 - Engines: Jacobs L6MB 300 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 23, 2008 - Departed: 4TN3, Moscow, TN - Destination: 4TN3, Moscow, TN - Airport: 4TN3, Hawk's Nest Airport, runway 36, 4,000 × 60 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 61; injuries: none; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review July 17, 2008; seat: left; flight hours: 2,659 total, 518 in this make and model, 2,150 as pilot in command, 21 in the last 90 days, 7 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 45 °F - Altimeter: 30.06 inHg - Observed at: OLV, 20 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 20081003847849A](https://openairdocs.org/incident/20081003847849A), Oct 3, 2008: Beech F17D, Moscow, TN, Substantial damage. (-23) On 10/07/2008, I investigated this assigned accident at hawk's Nest airport in Moscow TN. The pilot stated it was the second landing of the day and the… 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.