# NTSB FTW98LA048: Cessna 150F, N7934F, Brigham City, UT, November 1, 1997 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 31, 1997, 18:30 local (Nov 1, 1997, 01:30 UTC) - Place: Brigham City, UT - Coordinates: 41.509338, -112.040489 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.5093&lon=-112.0405&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 26, 1998 - Report: Approved by Office Director - NTSB case key (mKey): 20483 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW98LA048 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/20483/pdf - Page: https://openairdocs.org/ntsb/FTW98LA048 ## Probable cause failure of the pilot to maintain lateral (or vertical) clearance from a tree, during takeoff. Related factors were: the tree, and the pilot's improper use of flaps. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with object, takeoff - initial climb - object - tree(s) (contributing factor) - altitude/clearance - not maintained, pilot in command (cause) - lowering of flaps - improper, pilot in command (contributing factor) - In flight collision with object, emergency landing after takeoff - object - fence (contributing factor) ## Analysis The pilot was attempting to take off from an off-airport field and admitted he 'allowed impatience. . .to cloud (his) judgment.' He monitored the local AWOS (Automatic Weather Observation Station) broadcast and determined the wind to be from 315 degrees at 8 knots. The proposed takeoff direction was aligned with the wind. The temperature was 55 degrees F. The pilot determined there was 30 percent more field available than that required for a short-field takeoff. The takeoff ground roll was about 300 feet using 20 degrees of flaps. After liftoff, the right wing struck a tree, and the pilot decided to make an immediate landing. During the landing, the airplane struck a fence that surrounded the field. The Cessna 150F Pilot's Operating Handbook limited flaps to 10 degrees for short-field takeoffs. The investigation also revealed the pilot's third class medical certificate had expired, and he had not accomplished a recent biennial flight review. ## Factual narrative On October 31, 1997, approximately 1830 mountain standard time, a Cessna 150F, N7934F, was substantially damaged when it struck a tree and fence posts during takeoff from a field near Brigham City, Utah. The private pilot, the sole occupant aboard, was not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight being conducted under Title 14 CFR Part 91. The flight was originating when the accident occurred. The pilot's son, a student pilot, had used the airplane earlier in the day to make a round robin cross-country flight to Ogden, Utah. He made a forced landing in an open field near Brigham City Airport due to fuel exhaustion. The cause of the fuel exhaustion, according to an FAA inspector, was that the fuel filter housing was leaking. No airplane damage or occupant injuries were sustained in the forced landing. The airplane owner went to the site with the intention of ferrying the airplane to Brigham City, located about 3 miles to the north. He was concerned about vandalism and was reluctant to transport the airplane by truck, admitting "I allowed impatience and fear of vandalism to cloud my judgment." He serviced the airplane with 5 gallons of 87 octane autogas [the airplane has an STC (Supplemental Type Certificate) for autogas usage]. He then preflighted the airplane and found no discernible damage as a result of the forced landing. Monitoring Brigham City's AWOS (Automatic Weather Observation Station) broadcast on the aircraft's radio, the pilot said the wind was from 315 degrees at 8 knots and the proposed takeoff direction was aligned with the wind. The temperature was 55 degrees F. The pilot said he "stepped off" the field. Consulting the Pilot's Operating Handbook, he determined there was 30 percent more field available than that required for a short-field takeoff. The pilot took off using 300 feet for the ground roll with the flaps set at 20 degrees. About five feet above the ground, he initiated a shallow right turn. The airplane "over-responded and rolled too far to the right." The pilot leveled the wings but found the airplane wanted to fly "with the right wing down." He concluded the wing had struck the ground during the turn and damaged the aileron. He decided to make an immediate landing. During the landing, the airplane struck the fence surrounding the field. Postaccident inspection revealed damage to the right aileron and wing, left horizontal stabilizer, and fuselage skin near the left landing gear attach point. An FAA inspector who went to the scene determined that the right wing had struck a tree during the takeoff attempt. According to the Cessna 150F Pilot's Operating Handbook, the use of "10 degrees wing flaps reduces the total distance over an obstacle by approximately 10%. Flap deflections greater than 10 degrees are not approved for takeoff." The investigation also revealed the pilot's third class medical certificate had expired and he had not accomplished a recent biennial flight review. ## Aircraft - Registration: [N7934F](https://openairdocs.org/aircraft/N7934F), registered now, S/N 15064034 (OpenAirDocs) - Reported make and model: Cessna 150F - Registry model: [Cessna 150F](https://openairdocs.org/model/cessna-150f) (registry code 2071814) (OpenAirDocs) - Registry engine: [Continental 0-200 series](https://openairdocs.org/engine/continental-0-200-series) (registry code 17020, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 150-64034 - Airframe hours: 5468 - Engines: Continental O-200-A 100 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Herbert N. Pedersen - Airworthiness certificate: Standard, Normal - Last inspection: Annual, January 1, 1997, 25 hours before - Departed: NONE - Destination: BMC, UT ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 70; private; airplane ratings: single-engine land; medical: class 3, expired; seat: left; flight hours: 235 total, 118 in this make and model, 147 as pilot in command, 2 in the last 90 days ## Weather - Conditions: Visual (VMC), Dusk - Wind: 315° at 8 knots, gusting 12 - Visibility: 5 statute miles - Lowest ceiling: none - Temperature: 55 °F 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.