Columbia, CA, USA
N1364Q
CESSNA 150L
The flight instructor reported that the student pilot had recently purchased the airplane and that they intended to test fly it within the traffic pattern. Prior to departure, he noted that the wind was about 10-15 knots and favored a 2,600-foot-long turf runway. The instructor stated that he initiated a short field takeoff by holding the brakes, using 10 degrees of flaps, and applying full throttle. He recalled that the engine only produced 2,050 rpm, and that he expected the rpm to increase as he released the brakes. During the takeoff roll, the instructor felt that the tall grass slowed the acceleration of the airplane before it lifted off the ground at 55 miles per hour. He lowered the nose to gain airspeed in ground effect, but the airplane was not accelerating. Due to upward sloping terrain with trees and power lines in the flight path of the airplane, he turned left to avoid the obstacles. During the turn, the angle of bank increased due to a wind gust and the airplane stalled, entered a spin to the left, and impacted the ground in a nose low attitude. Examination of the airframe revealed no anomalies. Examination of the engine revealed that the number two cylinder top and bottom spark plugs were fouled with carbon deposits. These spark plugs would not have fired, resulting in a loss of power from the number two cylinder. The aircraft owner's manual states that during the initial takeoff phase the pilot should verify full throttle operation and that the engine should run smoothly and turn approximately 2,500 to 2,600 rpm with carburetor heat off.
On April 15, 2008, about 1600 Pacific daylight time, a Cessna 150L, N1364Q, sustained substantial damage when it impacted terrain following a loss of control during the takeoff initial climb from runway 29 at Columbia Airport (O22), Columbia, California. The flight instructor received minor injuries and the student pilot was not injured. The airplane was registered to, and being operated by, the student pilot as a 14 Code of Federal Regulations Part 91 instructional flight. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight, which was originating when the accident occurred. In a written statement, the flight instructor reported that the student pilot had recently purchased the airplane and the intention of the accident flight was to "test fly" it within the traffic pattern and land before planning their return flight to Idaho. Prior to departure, the instructor performed an engine runup and noted that the wind was from 300 degrees at 10 knots gusting to 15 knots, favoring runway 29, a 2,600-foot-long turf runway. Prior to initiating a short field takeoff, he held the brakes, selected 10 degrees of flaps, and applied full power while noting that the engine "only" produced 2,050 rpm. The instructor stated that he expected an increase in rpm as he released the brakes. During the takeoff roll, the instructor felt that the tall grass slowed the acceleration of the airplane before it lifted off the ground at 55 miles per hour. He lowered the nose to gain airspeed in ground effect, but the airplane was not accelerating. Due to upward sloping terrain with trees and power lines in the flight path of the airplane, he turned left to avoid the obstacles. During the turn, the "wind got under [the airplane's] right wing" and "steepened the bank." Subsequently, the airplane stalled, entered a spin to the left, and impacted the ground in a nose low attitude, resulting in structural damage to the fuselage and both wings. Examination of the airframe and engine on April 22, 2008, by representatives from Teledyne Continental Motors and Cessna Aircraft under the supervision of a Federal Aviation Administration (FAA) inspector revealed no anomalies with the airframe. The engine was separated from the airframe. All of the accessories remained attached to the engine crankcase. Continuity was established throughout the engine and valve train when the crankshaft was rotated by hand. Thumb compression was obtained on all four cylinders. The top and bottom spark plugs were examined and exhibited "worn-out normal" wear signatures when compared to the Champion Check-A-Plug comparison chart. The top and bottom number one, three, four, and top number two spark plugs exhibited dark gray deposits within the electrode area. The bottom number two spark plug exhibited an oily residue within the electrode area. A substance consistent with a carbon based material was observed bridging the gap between the ground and center electrodes on both the top and bottom number two cylinder spark plugs. It was noted that the right magneto ignition harness leads were connected to the upper number two and four cylinder positions and the bottom number one and three cylinder positions. The left magneto ignition harness was connected to the upper number one and three cylinder positions and the bottom number two and four cylinder positions. This is the reverse of the manufacturer's recommended connections. The right magneto drive shaft rotated freely with impulse coupling engagement and produced spark on three of the four terminals. The left magneto driveshaft rotated freely by hand with impulse coupling engagement and produced spark on all four terminals. The magnetos were removed and examined. The right magneto efficiency gap (E-gap) was measured at 10 degrees with a breaker point gap of .015 inches. The left magneto E-gap was measured at 21 degrees with a breaker point gap of .008 inches. The manufacturer specifies an E-gap of 10 degrees and a breaker point gap of .018 inches. No additional anomalies were noted with the engine. Review of maintenance records for the airframe and engine revealed that the airplane underwent its most recent annual inspection on December 14, 2007, at a total airframe time of 5,007.7 hours and an engine time since major overhaul (SMOH) of 440.7 hours. The most recent maintenance performed on the engine was an alternator removal and replacement conducted on April 5, 2008, at an engine time SMOH of 441.2 hours. At the time of the accident, the airframe and engine had accumulated 0.8 hours since the last annual inspection was performed. The owner's manual for a 1971 Cessna 150 states on page 11, under Take-Off, subheading Power Checks: "It is important to check full-throttle engine operation early in the takeoff run. Any signs of rough engine operation or sluggish engine acceleration is good cause for discontinuing take-off. If this occurs, you are justified in making a thorough full-throttle, static runup before another take-off is attempted. The engine should run smoothly and turn approximately 2,500 to 2,600 RPM with carburetor heat off."
The flight instructor's decision to attempt takeoff with an engine discrepancy and subsequent failure to abort takeoff when the airplane did not attain adequate airspeed during the initial climb, resulting in an aerodynamic stall. Contributing to the accident was the partial loss of engine power.
Source: NTSB Aviation Accident Database
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