# NTSB FTW98LA169: Aeronca 7DC, N4484E, Wright, WY, March 31, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 31, 1998, 11:00 local (18:00 UTC) - Place: Wright, WY - Coordinates: 43.749774, -105.490684 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.7498&lon=-105.4907&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 8, 1998 - Report: Approved by Office Director - NTSB case key (mKey): 20568 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW98LA169 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/20568/pdf - Page: https://openairdocs.org/ntsb/FTW98LA169 ## Probable cause The pilot's use of unsuitable terrain for takeoff. Factors were snow and rock covered terrain, inadequate aircraft preflight, improper aircraft servicing, and the fuel contaminated by water. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, cruise - fluid,fuel - contamination,water (contributing factor) - aircraft service - improper, pilot in command (contributing factor) - aircraft preflight - inadequate, pilot in command (contributing factor) - Forced landing, emergency landing - On ground/water encounter with terrain/water, takeoff - roll/run - unsuitable terrain or takeoff/landing/taxi area - selected, pilot in command (cause) - terrain condition - snow covered (contributing factor) - terrain condition - rock(s)/boulder(s) (contributing factor) ## Analysis After about 2 hours of flight, the aircraft was in cruise at 100 feet agl when the engine lost all power. The pilot landed in a field and drained water from the fuel. When he got the engine restarted, he attempted to take off, and during his takeoff roll the main landing gear entered a snow-covered area and the aircraft swerved into rocks. The pilot said that between flights he stored the aircraft with partially filled tanks in an area with high temperature variations over a 24-hour period. This practice enhances distillation of water in the tanks due to condensation. ## Factual narrative On March 31, 1998, at 1100 mountain standard time, a Aeronca 7DC, N4484E, received substantial damage when it struck rocks during takeoff roll from a field 60 miles south of Gillette, Wyoming. The private pilot and sole occupant was not injured. The flight was a local area flight operating under Title 14 CFR Part 91 and no flight plan was filed. Visual meteorological conditions prevailed. According to information provided by the pilot via his written report (NTSB Form 6120.1/2) and a telephone interview, after about two hours of flight the aircraft was in cruise at about 100 feet above ground level (agl) when the engine lost all power. The pilot performed a forced landing in a field and drained water from the fuel. After he got the engine restarted, he attempted a takeoff from the field and his main landing gear entered a snow covered area which caused the aircraft to swerve into rocks. In his telephone interview, the pilot said he normally did not refuel the aircraft until he was preparing for the next flight, which often was at an interval of several days or longer. Thus, his aircraft was sitting with partially filled fuel tanks in an environment where the differential temperature over a 24 hour period varies greatly. According to information provided by several aircraft manufacturers while this investigator was investigating similar accidents where water was found in the fuel, partially filled fuel tanks create a condition in which the fuel tank performs like a "still" and the tank will manufacture water by condensation. The greater the temperature variation, the more water is manufactured. ## Aircraft - Registration: [N4484E](https://openairdocs.org/deregistered/N4484E-2011-04-11), registration cancelled 2011-04-11, S/N 7DC-104, built 1948 (OpenAirDocs) - Reported make and model: Aeronca 7DC - Registry model: [Aeronca 7DC](https://openairdocs.org/model/aeronca-7dc) (registry code 2110116) (OpenAirDocs) - Registry engine: [Lycoming 0-290 series](https://openairdocs.org/engine/lycoming-0-290-series) (registry code 41506, 4 cycle) (OpenAirDocs) - Category: Airplane - Serial number: 104 - Airframe hours: 3737 - Engines: Continental O-320 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Daniel L. Morgan - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, April 5, 1997, 193 hours before - Departed: GCC, GILLETTE, WY ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 41; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: front; flight hours: 874 total, 250 in this make and model, 840 as pilot in command, 80 in the last 90 days, 42 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 240° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 28 °F, dew point 23 °F - Altimeter: 29.00 inHg - Observed at: GCC, 60 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 19980331005289A](https://openairdocs.org/incident/19980331005289A), Mar 31, 1998: Bbavia 7DC, Wright, WY, Substantial damage. Cruising 100FT AGL engine quit. Force landed in field. Drained water in fuel hit snow departing. Veered into rocks. (.4)after about 2 hours of flight, 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.