# NTSB FTW93LA171: Ayres SR2-T34, N6051F, Harrisburg, AR, May 31, 1993 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 31, 1993, 15:30 local (20:30 UTC) - Place: Harrisburg, AR - Coordinates: 35.559658, -90.71997 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.5597&lon=-90.7200&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 30, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 18760 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW93LA171 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/18760/pdf - Page: https://openairdocs.org/ntsb/FTW93LA171 ## Probable cause THE LOSS OF ENGINE POWER DUE TO THE FAILURE OF THE REDUCTION GEAR ASSEMBLY DUE TO FATIGUE. A FACTOR WAS THE LACK OF SUITABLE TERRAIN FOR THE FORCED LANDING. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, cruise - reduction gear assy,reduction gear - jammed (cause) - reduction gear assy,reduction gear - fatigue (cause) - Forced landing, descent - emergency - In flight collision with terrain/water, landing - flare/touchdown - terrain condition - dirt bank/rising embankment - terrain condition - none suitable (contributing factor) ## Analysis AN AGRICULTURAL AIRPLANE WITH A FULL LOAD OF PESTICIDES WAS EN ROUTE TO A FIELD TO BE SPRAYED WHEN THE ENGINE OIL PRESSURE DROPPED AND THE ENGINE CHIP DETECTOR ILLUMINATED. WITHIN SECONDS, THE ENGINE LOST POWER AND THE PILOT ELECTED TO EXECUTE A FORCED LANDING TO A CULTIVATED FIELD. DURING THE LANDING FLARE, THE AIRPLANE STRUCK A LEVEE RESULTING IN STRUCTURAL DAMAGE TO THE AIRFRAME AND ENGINE FIREWALL. EXAMINATION OF THE ENGINE REVEALED THAT THE POWER LOSS WAS THE RESULT OF FIRST STAGE PLANETARY SUNGEAR FAILURE DUE TO FATIGUE. ## Factual narrative On May 31, 1993, at approximately 1530 central daylight time, an Ayres Corporation SR2-T34 airplane, N6051F, was substantially damaged during a forced landing following a loss of engine power while in cruise flight near Harrisburg, Arkansas. The commercial pilot, sole occupant of the airplane, was not injured. Visual meteorological conditions prevailed for the aerial application flight. According to the operator, the airplane departed the May private airstrip near Harrisburg, with a full load of pesticides. While en route to the field to be sprayed, the engine oil pressure dropped and the engine chip detector illuminated. Within a few seconds, the engine lost power and the pilot performed a forced landing to a field. During the landing flare, the airplane struck a levee resulting in structural damage to the airframe and engine firewall. The engine was preserved and transported to an approved repair station for further inspection and examination. Inspection of the magnetic plug and the screen confirmed that ferrous deposits were present. A complete engine teardown was accomplished. According to the engine manufacturer's representative, "the failure of the engine appeared to originate in the first stage planetary system." A detailded examination of the first stage sungear revealed "some areas of fatigue along the axis of the splines, which resulted in the jamming of the first stage sun gear." The wreckage was verbally released to the owner at the accident site. ## Aircraft - Registration: [N6051F](https://openairdocs.org/deregistered/N6051F-1997-04-29), registration cancelled 1997-04-29, S/N T34193 (OpenAirDocs) - Reported make and model: Ayres SR2-T34 - Registry model: [Ayres S2R-T34](https://openairdocs.org/model/ayres-s2r-t34) (registry code 0970106) (OpenAirDocs) - Category: Airplane - Serial number: T34-193 - Engines: P&W PT6A-34 750 horsepower turbo prop - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Ken Grubbs Aero, Inc. - Airworthiness certificate: Special, Restricted (Special) ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 29; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 8,731 total, 550 in this make and model, 8,600 as pilot in command, 500 in the last 90 days, 50 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 10° at 8 knots - Visibility: 12 statute miles - Lowest ceiling: 2,600 ft broken - Temperature: 64 °F, dew point 50 °F - Altimeter: 29.00 inHg - Observed at: JBR, 19 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 19930531016049A](https://openairdocs.org/incident/19930531016049A), May 31, 1993: Ayres S2RT34RESTD, Harrisburg, AR, Substantial damage. En route to spray. Lost power. Struck levee landing. Damaged airframe. Engine first stage planetary sungear failed. 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.