# NTSB FTW97LA035: Stinson 108-3, N798C, Tyler, TX, November 3, 1996 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: November 3, 1996, 13:30 local (19:30 UTC) - Place: Tyler, TX - Location: 32.3823° N, 95.4072° W: Placed by OpenAirDocs from NTSB’s distance and direction from TYLER POUNDS RGNL (TYR), within about a mile (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=32.3823&lon=-95.4072&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report February 1, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 20109 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW97LA035 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/20109/pdf - Page: https://openairdocs.org/ntsb/FTW97LA035 ## Probable cause a loss of engine power due to failure of the crankshaft. 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, approach - vfr pattern - base leg/base to final - engine assembly,crankshaft - failure (cause) - Forced landing, emergency descent/landing - Nose over, emergency landing - terrain condition - ditch - terrain condition - none suitable (contributing factor) ## Analysis According to the pilot, he observed the 'tachometer RPM changing drastically' while the airplane was on a 2 to 2.5 mile extended downwind leg for landing on runway 13. The pilot reported the anomaly to the tower, advising that he needed to land. The tower controller immediately issued the pilot a clearance to execute a left turn and proceed for a straight-in approach to runway 17. The pilot further stated that about 30 seconds after turning for runway 17, the engine started 'to make a loud popping and backfiring noise,' followed by total loss of power. The pilot notified the controller of his predicament and advised that he would not be able to reach the runway. The pilot elected to land the airplane on a nearby field to the right of his course, approximately 1.5 miles north of the threshold for runway 17. During the landing roll, the main gear hit a drainage ditch along the side of a road that crossed the field, and the airplane nosed over. Examination and teardown of the engine revealed that the crankshaft had failed in a heavy cast area (web) between the #1 and #2 rod journals. ## Factual narrative On November 3, 1996, at 1330 central standard time, a Stinson 108-3 airplane, N798C, was substantially damaged during a forced landing near Tyler, Texas. The airplane, owned and operated by a private owner, was being operated under Tittle 14 CFR Part 91. The private pilot and his passenger were not injured. Visual meteorological conditions prevailed for the personal flight for which a flight plan was not filed. The flight originated from the Cherokee County Airport near Jacksonville, Texas, at approximately 1245. According to the pilot, he observed the "tachometer RPM changing drastically" while the airplane was on a 2 to 2.5 mile extended downwind leg for landing on runway 13 at the Tyler Pounds Field. The pilot reported the anomaly to the tower advising them that he needed to land. The tower immediately issued the pilot a clearance to execute a left turn and proceed for a straight-in approach to runway 17. The pilot added that he complied immediately and aligned the airplane for landing on runway 17. The pilot further stated that about 30 seconds after turning toward runway 17, the "engine started to make a loud popping and backfiring noise," followed by the total loss of power. The pilot notified the tower of his predicament and advised them that he would not be able "to make the runway." The pilot elected to land the airplane on a field to the right of his course, approximately 1.5 miles north of the threshold for runway 17. During the landing roll, "the mains hit a drainage ditch along side a road crossing the field" and the airplane nosed over, coming to a stop in the inverted position. Examination of the airplane by the FAA inspector revealed that both wing struts sustained structural damage. Further examination and teardown of the engine by the owner revealed that the loss of engine power was attributed to the failure of the crankshaft in the heavy cast (web) area between the #1 and #2 rod journals. See enclosed report for further details of the examination. The 1947 vintage airplane was rebuilt by the pilot in 1993. He stated that at that time he outfitted the airplane with shoulder harnesses. He credited the absence of injuries to either occupants to the use of the shoulder harnesses. ## Aircraft - Registration: [N798C](https://openairdocs.org/aircraft/N798C), registered now, S/N 108-3798, built 1947 (OpenAirDocs) - Reported make and model: Stinson 108-3 - Registry model: [Stinson 108-3](https://openairdocs.org/model/stinson-108-3) (registry code 9230408) (OpenAirDocs) - Registry engine: [Franklin 6A4165 series](https://openairdocs.org/engine/franklin-6a4165-series) (registry code 27025, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 108-3798 - Airframe hours: 1883 - Engines: Franklin 6A4-165-BB 165 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Sam B. Bales - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 29, 1996, 13 hours before - Departed: JSO, JACKSONVILLE, TX - Destination: TYR - Airport: TYR, Pounds Field, runway 17, 4,849 × 150 ft, concrete ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 64; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 335 total, 233 in this make and model, 260 as pilot in command, 12 in the last 90 days, 8 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 5 knots - Visibility: 15 statute miles - Lowest ceiling: 25,000 ft broken - Temperature: 72 °F - Altimeter: 30.00 inHg - Observed at: TYR, 1 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 19961103034739A](https://openairdocs.org/incident/19961103034739A), Nov 3, 1996: Univar 1083, Tyler, TX, Substantial damage. Aircraft engine quit on downwind leg to runway and aircraft landed short of runway. (-23) engine failed while on base leg to runway at tyr. Pilot selected a… ## Other investigations on N798C (1) 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. - [NTSB FTW67D0336](https://openairdocs.org/ntsb/FTW67D0336), Nov 26, 1966: Stinson 108-3 (N798C), Houston, TX, substantial damage 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.