# NTSB FTW04LA124: Aeronca 7AC, N3708E, Fort Stockton, TX, May 8, 2004 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 8, 2004, 18:22 local (23:22 UTC) - Place: Fort Stockton, TX - Coordinates: 30.915555, -102.916114 - Nearby events: https://openairdocs.org/map.md?lat=30.9156&lon=-102.9161&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report September 29, 2004 - Report: Approved by Office Director - Parties: Lubbock FSDO - NTSB case key (mKey): 59180 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW04LA124 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/59180/pdf - Page: https://openairdocs.org/ntsb/FTW04LA124 ## Probable cause The pilot's improper leaning of the fuel/air mixture in-flight, which resulted in a loss of engine power. Factor were the wind gusts and the crosswind. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, cruise - mixture - improper use of, pilot in command (cause) - Forced landing, descent - emergency - On ground/water collision with object, landing - object - fence post - object - tree(s) - weather condition - crosswind (contributing factor) - weather condition - gusts (contributing factor) ## Analysis The 821-hour commercial pilot lost engine power while in cruise flight at 2,500 feet mean sea level approximately 25 miles west of his intended destination. While en route, he noticed the oil temperature gauge indicated 240 degrees (red line was 145 degrees). The pilot reduced engine rpm from 2,400 to 2,200, and increased the airplane's mixture setting. The oil temperature began to decrease. Shortly after, the engine suddenly began to lose power. The pilot increased the mixture setting to "full rich", and applied carburetor heat, but the engine continued to lose power. He was unable to maintain altitude and executed a forced landing to a service road on Interstate 10. Upon landing, the pilot was unable to keep the airplane straight due to the strong, gusting crosswinds and collided with a metal fence post and mesquite trees. Examination of the top and bottom spark plugs revealed the #2 and #4 plugs were oily, and the #1 and #3 plugs appeared white in color. The oil, which was changed approximately 8 hours before the accident, was dark in color. When asked how this accident could have been prevented, the pilot reported, "I probably leaned engine too much too long causing the oil temp[erature] to reach 240 degrees. Run aircraft more rich to provide better cooling to internal combustion chambers." Weather reported at an airport about 17 miles from the accident site were reported as wind from 130 degrees at 17 knots gusting to 24 knots. ## Factual narrative On May 8, 2004, approximately 1822 central daylight time, an Aeronca 7AC single-engine airplane, N3708E, registered to and operated by a private individual, sustained substantial damage during a forced landing to a road following a loss of engine power near Fort Stockton, Texas. The commercial pilot and the passenger were not injured. A visual flight rules (VFR) flight plan was filed for the cross-country flight that departed Culberson County Airport (VHN) near Van Horn, Texas, about 1710, destined for Fort Stockton-Pecos County Airport (FST), Pecos, Texas. Visual meteorological conditions prevailed for the personal flight conducted under 14 Code of Federal Regulations Part 91. In a written statement, the 821-hour pilot reported that while in cruise flight at 2,500 feet mean sea level approximately 25 miles west of Fort Stockton, he noticed the oil temperature gauge indicated 240 degrees (red line was 145 degrees). He reduced engine rpm from 2,400 to 2,200, and increased the airplane's mixture setting. The oil temperature began to decrease. Shortly after, about 17 miles west of Fort Stockton, the engine suddenly began to lose power. The pilot increased the mixture setting to "full rich", and applied carburetor heat, but the engine continued to lose power. He was unable to maintain altitude and executed a forced landing to a service road on Interstate 10. Upon landing, the pilot was unable to keep the airplane straight due to the strong, gusting crosswinds and collided with a metal fence post and mesquite trees. The pilot reported that the right wing and fuselage sustained structural damage. A Federal Aviation Administration inspector performed an examination of the engine. According to the inspector, the engine was manually rotated, and compression and valve train continuity were established for each cylinder. The top and bottom spark plugs were removed; the #2 and #4 plugs appeared to be oily, and the #1 and #3 plugs appeared white in color. The oil, which was changed approximately 8 hours before the accident, was dark in color. When asked how this accident could have been prevented, the pilot reported, "I probably leaned engine too much too long causing the oil temp[erature] to reach 240 degrees. Run aircraft more rich to provide better cooling to internal combustion chambers." Weather at Fort Stockton at 1753 was reported as wind from 130 degrees at 17 knots gusting to 24 knots, visibility 10 miles, and clear skies. ## Aircraft - Registration: [N3708E](https://openairdocs.org/aircraft/N3708E), registered now, S/N 7AC-7009, built 1947 (OpenAirDocs) - Reported make and model: Aeronca 7AC - Registry model: [Aeronca 7AC](https://openairdocs.org/model/aeronca-7ac) (registry code 2110102) (OpenAirDocs) - Registry engine: [Continental A&C65 series](https://openairdocs.org/engine/continental-a-c65-series) (registry code 17003, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 7AC-7009 - Airframe hours: 1985 - Engines: Lycoming O-235 108 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Stanley Hoffpauir - Airworthiness certificate: Standard, Normal - Last inspection: Annual, January 14, 2004, 6 hours before - Departed: VHN, Van Horn, TX - Destination: FST, Fort Stockton, TX - Flight plan: VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 62; injuries: none; commercial; medical: class 3, valid medical--w/ waivers/lim; last flight review December 26, 2003; seat: front; flight hours: 821 total, 81 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 17 knots, gusting 24 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 86 °F, dew point 59 °F - Altimeter: 29.94 inHg - Observed at: FST, 25 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 20040508007039A](https://openairdocs.org/incident/20040508007039A), May 8, 2004: Bbavia 7AC, Fort Stockton, TX, Substantial damage. (-23) On may 8, 2004, at approximately 1822 CDT local time, the pilot of N3708E, an Aeronca champ 7AC aircraft, experienced loss of power and subsequently made… ## Other investigations on N3708E (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 FTW85LA243](https://openairdocs.org/ntsb/FTW85LA243), Jun 1, 1985: Aeronca 7AC (N3708E), Edna, 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.