# NTSB DEN03LA089: Beech A36, N2106L, Afton, WY, May 26, 2003 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 26, 2003, 11:00 local (17:00 UTC) - Place: Afton, WY - Coordinates: 42.711112, -110.941947 - Nearby events: https://openairdocs.org/map.md?lat=42.7111&lon=-110.9419&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report November 25, 2003 - Report: Approved by Office Director - Parties: FAA Flight Standards Field Office - NTSB case key (mKey): 57068 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN03LA089 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/57068/pdf - Page: https://openairdocs.org/ntsb/DEN03LA089 ## Probable cause the pilot's failure to achieve an adequate climb rate, resulting in an inflight collision with the sign. Contributing factors were the pilot's improper mixture leaning procedure, the high density altitude, his failure to abort the takeoff in a timely manner, and the highway sign near the end of the runway. ## 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 - mixture - improper use of, pilot in command (contributing factor) - aborted takeoff - not performed, pilot in command (contributing factor) - weather condition - high density altitude (contributing factor) - climb - inadequate, pilot in command (cause) - object - sign (contributing factor) ## Analysis The pilot had three passengers and 50 gallons of fuel on board when he made the first scenic flight. The density altitude was reported to be 7,200 feet msl. On the second flight, he had another three passengers and 38 gallons of fuel. Density altitude had increased to 8,500 feet msl. The mixture was leaned. The pilot said "the plane did not develop the same amount of power as on the previous takeoff" and the takeoff roll was longer. "The plane rotated approximately 200 yards before the departure end of the runway, and did not accelerate beyond 70 knots." He lowered the nose to gain airspeed. Airspeed slowly increased and the airplane "was ascending at about the same rate as the terrain. Approximately eight seconds after take off, I felt a slight surge in power and lifted the nose." He then heard a "pop" and "felt a slight shudder." He concluded he had "grazed over the top of some object with the stinger at the rear of the plane." Concerned about possible damage to the airplane, the pilot radioed the airport manager and asked that he inspect the airplane when he made a low pass over the airport. He lowered the landing gear and flew over the runway. The airport manager advised him that "everything looked fine." The pilot then proceeded with the flight. As the passengers disembarked, they noticed the rear foot step had been knocked off. Further investigation revealed a gash under the right wing, 2 feet outboard from the fuselage, that extended from just aft of the leading edge to the flap. Based on a maximum gross weight of 3,600 pounds and a density altitude of 8,500 feet, it was computed that the airplane would require 2,100 feet for the takeoff roll and would climb approximately 600 feet per minute. According to the engine manufacturer, a full power setting is to be used for pre-takeoff leaning on all normally-aspirated reciprocating engines. This information is contained in the various engine handbooks. If the engine were to be leaned at a lower power setting, the mixture would become richer as power was increased beyond the setting used for leaning, and would result in lower rpm and reduced horsepower. ## Factual narrative On May 26, 2003, approximately 1100 mountain daylight time, a Beech A36, N2106L, was substantially damaged when it struck a sign during takeoff at Afton Municipal Airport, Afton, Wyoming. The private pilot and three passengers were not injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the personal flight being conducted under Title 14 CFR Part 91. The local flight was originating at the time of the accident. According to the pilot, he had 50 gallons of fuel on board and the density altitude was reported to be 7,200 feet msl when he took off with three passengers for a local scenic flight. When he returned about 45 minutes later, three other passengers asked to go on a similar flight. No fuel was added, and the pilot estimated he had approximately 38 gallons of fuel remaining. Engine start, taxi and run-up were uneventful. Density altitude was reported to be 8,500 feet msl, and the mixture was leaned. The pilot said "the plane did not develop the same amount of power as on the previous takeoff" and the takeoff roll was longer. "The plane rotated approximately 200 yards before the departure end of the runway," he wrote, "and did not accelerate beyond 70 knots." He lowered the nose to gain airspeed. Airspeed slowly increased and the airplane "was ascending at about the same rate as the terrain. Approximately eight seconds after take off, I felt a slight surge in power and lifted the nose." He then heard a "pop" and "felt a slight shudder." He concluded he had "grazed over the top of some object with the stinger at the rear of the plane." Concerned about possible damage to the airplane, the pilot radioed the airport manager and asked him to inspect the airplane when he made a low pass over the airport. He lowered the landing gear and flew over the runway. The airport manager advised him that "everything looked fine." The pilot then proceeded with his scenic flight which lasted about 25 minutes. After an uneventful landing and as the passengers disembarked, they noticed the rear foot step had been knocked off. Further investigation showed a gash under the right wing, 2 feet outboard from the fuselage, that extended from just aft of the leading edge to the flap. The pilot said he had struck a "highway sign." The performance charts in the Beech A36 Pilot Operating Handbook/FAA Approved Airplane Flight Manual were consulted. Based on a maximum gross weight of 3,600 pounds and a density altitude of 8,500 feet, it was computed that the airplane would require 2,100 feet for the takeoff roll, and would climb approximately 600 feet per minute. According to Teledyne Continental Motors, a full power setting is to be used for pre-takeoff leaning on all their normally-aspirated reciprocating engines. This information is contained in the various engine handbooks. If the engine were to be leaned at a lower power setting, the mixture would become richer as power was increased beyond the setting used for leaning, and would result in lower rpm and reduced horsepower. ## Aircraft - Registration: [N2106L](https://openairdocs.org/aircraft/N2106L), registered now, S/N E-878, built 1976 (OpenAirDocs) - Reported make and model: Beech A36 - Registry model: [Beech A36](https://openairdocs.org/model/beech-a36) (registry code 1151604) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: E878 - Airframe hours: 3715 - Engines: Continental IO-520-BB56B 285 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 16, 2003, 41 hours before - Departed: KAFO, Afton, WY - Airport: AFO, AftonMunicipal, runway 34, 5,220 × 75 ft, concrete ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 57; injuries: none; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; last flight review April 14, 2002; seat: left; flight hours: 396 total, 250 in this make and model, 240 as pilot in command, 52 in the last 90 days, 28 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 68 °F, dew point 43 °F - Altimeter: 30.11 inHg - Observed at: JAC ## 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 20030526010459A](https://openairdocs.org/incident/20030526010459A), May 26, 2003: Beech A36, Afton, WY, Substantial damage. (-23) During take off at the Afton, Wyoming airport the aircraft N2106L, with Mr. James l. crandell acting as pilot-in-command struck a wood sign post causing… 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.