HISTORY OF FLIGHTOn May 22, 2014, about 1830 central daylight time, a special light sport P&M Aviation QuikR weight shift aircraft, N428PM, was substantially damaged at Jack Edwards National Airport (JKA), Gulf Shores, Alabama. The airline transport pilot sustained serious injuries. Visual meteorological conditions prevailed for the personal flight and no flight plan was filed for the local flight. The flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91.
According to the pilot's written statement, he performed a preflight inspection of the aircraft and then attempted to start the engine in an area surrounded by hangars. He applied full choke, set the hand throttle to idle, applied full left foot brake and placed the magnetos in the ON position. After making about four unsuccessful attempts to start the engine, the pilot moved the choke back and forth and left it about halfway. He introduced a "little bit of right foot throttle" and, after about four more attempts, the engine started and "immediately" advanced to "takeoff power." The pilot applied full left foot brake, but the aircraft moved forward at increasing speed. He attempted to keep the aircraft on the taxiway centerline by steering the nose wheel. The pilot also held the control bar with his left hand and groped the instrument panel with his right hand for the magneto cutoff. He eventually disengaged one of the two magnetos; however, the right wing of the aircraft impacted the cowling of a parked airplane located to the right of the taxiway centerline. The aircraft spun to the right, impacted a hangar door, and came to rest.
Postaccident examination of the accident aircraft by a Federal Aviation Administration (FAA) inspector revealed damage to the left wing spar. The parked airplane also sustained damage to the propeller and nose cowling. Further examination of the engine control system revealed that the foot pedal throttle and hand throttle both operated smoothly with no binding. PERSONNEL INFORMATIONThe pilot held an airline transport certificate with ratings for airplane single and multiengine land. He had accumulated about 12,737 total hours of flight time, of which 72 hours were in the accident airplane make and model. AIRCRAFT INFORMATIONAccording to the FAA Aircraft Registry, the accident airplane was manufactured in 2009. The special light sport weight-shift-control category aircraft was equipped with a three-bladed Warp Drive propeller and one Rotax 912ULS model four stroke engine, rated at 100 horse-power. The airplane's most recent condition inspection was completed on April 1, 2014, and at that time the airplane had accumulated 179.1 total flight hours.
Throttle System
The airplane was equipped with a foot throttle that automatically returned to the CLOSED position, similar to the accelerator in an automobile, and a friction-dampened hand throttle. The airplane was also equipped with a starter motor solenoid interrupt switch that prevented the engine from starting with the handle throttle engaged. The throttle cables connected to a splitter, which contained a single piston that was designed to open and close the butterfly valves to both carburetors when the throttles were moved. The carburetors were originally designed by the engine manufacturer to default to the open position in the event of a severed cable, but were altered by the airframe manufacturer to spring-shut. METEOROLOGICAL INFORMATIONThe 1835 recorded weather observation at JKA included wind from 240 degrees at 9 knots, temperature 27 degrees C, and an altimeter setting of 30.09 inches of mercury. AIRPORT INFORMATIONAccording to the FAA Aircraft Registry, the accident airplane was manufactured in 2009. The special light sport weight-shift-control category aircraft was equipped with a three-bladed Warp Drive propeller and one Rotax 912ULS model four stroke engine, rated at 100 horse-power. The airplane's most recent condition inspection was completed on April 1, 2014, and at that time the airplane had accumulated 179.1 total flight hours.
Throttle System
The airplane was equipped with a foot throttle that automatically returned to the CLOSED position, similar to the accelerator in an automobile, and a friction-dampened hand throttle. The airplane was also equipped with a starter motor solenoid interrupt switch that prevented the engine from starting with the handle throttle engaged. The throttle cables connected to a splitter, which contained a single piston that was designed to open and close the butterfly valves to both carburetors when the throttles were moved. The carburetors were originally designed by the engine manufacturer to default to the open position in the event of a severed cable, but were altered by the airframe manufacturer to spring-shut. WRECKAGE AND IMPACT INFORMATIONThe initial impact point was the cowling of a parked airplane located about 150 feet from the accident pilot's hangar. According to the FAA inspector, the left wing spar was broken and there was torn cloth on both the left wing and top center sail. All flight control surfaces remained attached to their respective airframe components, and flight control continuity was traced from each flight control surface to the cockpit. All three carbon fiber propeller blades had separated; blade A was broken outboard, blade B was broke mid-span, and blade C was broken inboard near the hub.
Further examination took place in a secure hangar at JKA by a representative of the airframe manufacturer under the supervision of a FAA inspector. The engine case was undamaged and free of oil or fuel leaks. The right throttle foot pedal was operated several times and some abnormal friction was noted; however, both carburetors opened and closed each time the foot pedal was depressed and released. The hand throttle was also advanced to the ON position and retarded to the OFF position several times, and during each operation both carburetors opened and closed. During each operation of the hand throttle, the hand throttle interrupt switch could be heard, which indicated that the solenoid switch was engaging. The hand choke also functioned normally and no binding or damage was noted.
The foot throttle cable extended from the right foot pedal behind a pod support bracket and to the left foot position along the basetube. Postaccident examination revealed two snag hazards that caused the foot throttle to remain in the open position. In one example, when the foot throttle was depressed the throttle cable could be manipulated by hand to snag on a bolt that fastened the pod support bracket to the fuselage. In another example, the foot throttle cable could be manipulated by hand to snag on the pilot's left foot, which unseated the throttle cable end and caused the foot throttle to stick open. ADDITIONAL INFORMATIONStarting Instructions
According to the section entitled "6.3 Starting Engine" in the manufacturer's operating instructions:
6.3 Starting Engine
The pilot must always start the engine when sitting in the cockpit with seatbelts secured and helmet worn.
Pre-start checks:
1. Passenger should also be strapped in and briefed.
2. Throttles both working and fully shut (never use the hand throttle for engine control on the
ground).
· If starter interrupt switch is fitted, starter will not operate unless hand throttle is CLOSED.
Warning: Engine start-up is always a potentially dangerous time. Make sure that you have done all your checks, that you are not disturbed while doing them, and that you are entirely happy that the aircraft is in a fit state to be started-up. Finally, before start-up, ensure that the aircraft is pointing away from people/vehicles/buildings etc, and that there are no pets or other animals which could panic after start-up. Double check that the propeller is clear and hand throttle is closed before starting the engine.
STARTING: check visually again that the propeller area is clear and call "Clear Prop" loudly. Pause. Turn on the key switch, set the contacts to ON, then push the button in 5 seconds bursts. Release the button as soon as the engine fires. If the engine refuses to start after 5 or 6 attempts, close the controls and switch OFF the ignition before investigation.