NTSB Factual Report

On September 23, 2008, about 1110 Pacific daylight time, an amateur-built Laurence Ray Simpson Amphibious weight-shift Trike airplane, N440LS, sustained substantial damage following a loss of control and impact with terrain at the Lake Chelan Airport (S10), Chelan, Washington. The certificated airline transport pilot, the sole occupant, was seriously injured. Visual meteorological conditions prevailed for the planned local flight, which was operated in accordance with 14 Code of Federal Regulations (CFR) Part 91, and a flight plan was not filed. The flight was originating at the time of the accident.

According to the Pilot/Operator Aircraft Accident/Incident Report (NTSB Form 6120.1), the pilot reported that during the takeoff roll at 40 miles per hour (mph) his scan shifted to the far end of the runway, and "...[the] wing lift was delayed by 'pulling in' (adjusted angle-of-attack). Shortly thereafter 'wing-out' was initiated and aircraft lifted off. [An] angle-of-attack adjustment was made [and the] aircraft swerved hard to the [left]. [A] correction was applied [and the] aircraft corrected back to [the runway] centerline. [A] second swerve to the left was uncorrected and impact with the ground became inevitable." In the report the pilot listed 48 hours of pilot-in-command time in make and model at the time of the accident.

Multiple witnesses adjacent to the accident site submitted witness statements to local law enforcement shortly after the accident. The first witness stated that he observed the accident airplane start its takeoff rollout slowly, and "After about 250 feet [it] became airborne. [The accident airplane] looked as though [it] was climbing quite rapidly. [Its] left wing dipped slightly and then severely. [It] had only traveled about 100 feet in the air when [it] changed direction and dove into the ground." The second witness reported the she observed the airplane begin its takeoff "...traveling from the far end of the runway towards us. Suddenly the left side (from my view) flipped up as if blown by a [wind] gust and the plane veered and flipped to the right." The third witness revealed, "I did not observe the initial part of the takeoff. I heard my wife exclaim, and looked up to see the ultra light approximately 30 feet above the ground in a steep nose down attitude (50 degrees nose down) left wing low. I observed the impact." The fourth witness reported observing the airplane about 75 feet to 100 feet above the ground with its left wing down. She stated that the wind was a little gusty at the time, "...but not unexceptionally so."

A Federal Aviation Administration (FAA) airworthiness inspector, who conducted a postaccident examination of the airplane, reported that all flight controls were intact, the wing did not separate from the airplane structure, and that the fuselage broke away from the floats. The inspector further reported that no pre-impact anomalies existed with the airplane that would have precluded normal operation. The inspector revealed that a review of the pilot's personal logbook indicated a total logged time in weight-shift aircraft of 26.5 hours.

In a statement submitted to the NTSB investigator-in-charge (IIC) dated December 3, 2008, a local certified sport pilot flight instructor reported, ["The accident pilot] brought his amphibious float trike to our training facility for assistance in getting his aircraft certified with an airworthiness certificate, as well as flight training in his own aircraft." The flight instructor further reported, "Upon [the accident pilot] receiving his airworthiness certification and prior to [the accident pilot] commencing any flight training, I threw my back out and was in bed for two weeks. At that time I had a conversation with [the accident pilot] about my condition, and that it would be a while before he could receive flight instruction from me. I offered to find him another instructor, but he decided that he would wait for me to get better. At that time I specifically stated to [the accident pilot] 'Do not attempt to fly this machine until [you] have received adequate training.' He assured me he would wait to receive training from me. I never saw his log book but was told by [the accident pilot] that he was a high time commercial pilot, with over 500 hours on general aviation float aircraft, and approximately 30 hours of land based Trike time and instruction, with 1 hour or so of float time in the back seat." The flight instructor revealed "...[the accident pilot] was flying a 19-meter wing, which has a tremendous lifting capacity; I have seen it before on the 19-meter wings with an inexperienced pilot. Once the pilot brings the trike up to full power the trike becomes light on the landing gear and the inexperience of the pilot makes him think he is airborne. Then the inexperienced pilot pushes out on the control bar thinking he will climb out. However, not having enough airspeed to sustain flight, the aircraft will begin to become a takeoff stall."

At 1055, the Automated Surface Observing System (ASOS) at the Pangborn Memorial Airport (EAT), Wenatchee, Washington, which is located 35 nautical miles south-southwest of S10, reported wind calm, visibility 10 miles, sky clear, temperature 11 degree Celsius, dew point -1 degree Celsius, and an altimeter setting of 30.25 inches of Mercury.

NTSB Probable Cause

The pilot's failure to maintain adequate airspeed during the initial climb, which resulted in an inadvertent aerodynamic stall. Contributing to the accident was the pilot's lack of experience in the float-equipped, weight-shift airplane.