NTSB Factual Report

HISTORY OF FLIGHT

On July 27, 2017, at 1943 central daylight time, an Aerofab, Inc., Lake LA-4-250 amphibious airplane, N1400P, was substantially damaged when it impacted water during takeoff from Vette/Blust Seaplane Base (96WI), Oshkosh, Wisconsin. The airline transport pilot and one passenger were fatally injured, and the pilot-rated passenger received minor injuries. The airplane was owned by the pilot who was operating it under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed at the accident site about the time of the accident, and no flight plan was filed for the personal flight, which was originating at the time of the accident with an intended destination of Southwest Regional Airport, Marshall, Minnesota.

The harbormaster and the chairman of the seaplane base both provided statements that indicated that the airplane arrived at 96WI about 1230 on the day of the accident. After landing, the pilot requested assistance during taxi because the left wing sponson was taking on water. Boats were used to tow the airplane to the seabase.

The pilot and two passengers departed the seaplane base and returned about 2 hours later. Around 1430 the pilot was taken to his airplane while it was moored in the bay. He started the engine while the airplane was stilled tied to a mooring plug and the airplane began to turn in a circle. When the volunteer boat crew stopped him and asked what he was trying to do he was very argumentative and said, "you can't prevent me from leaving with my aircraft." The volunteer proceeded to explain he simply wanted to help and that he wasn't going to be able to move the airplane unless he untied from the mooring plug. The airplane was then untied and towed to the ramp where the pilot drained water from the left sponson. Four to five gallons of fuel was also drained from the left sponson fuel tank (a separate tank isolated inside the sponson). At this time an inspection cover was discovered missing from the underside of the left wing, outboard of the sponson. A field repair was made to cover the hole. The airplane was subsequently moored and appeared to sit normally in the water. No additional issues were noted with the sponson taking on water prior to the airplane departing for the accident flight.

After the accident pilot drained the sponson, seaplane base personnel and other pilots expressed concern to the accident pilot regarding the rough water conditions and attempted to discourage him from departing. In order to convince the pilot of the conditions, the harbormaster and chairman took the pilot out on the lake by boat to observe the water conditions. The harbormaster described the waves being 1 ½ to 2 ft at that time. The chairman stated that the pilot indicated on two occasions during the boat ride that the waves were too big and the water conditions were unacceptable. The pilot later said he would take off parallel to the swells in a northwesterly direction. The chairman questioned the pilot as to why he would take off in that direction, since it would clearly be a downwind takeoff in large wave conditions. The chairman then told the pilot . "you will never get airborne with a Lake, with full fuel, three passengers, heavy wave conditions and downwind - never!" The chairman showed the pilot that all the seaplanes moored at the base were pointing southeast, into the wind. The pilot then asked to be taken back to the dock and to have the airplane fueled. The airplane's main tanks were fueled, but no fuel was put into either sponson tank.

The pilot later approached the seaplane base staff and indicated that he was ready for departure. The harbormaster towed the seaplane from the dock, through a narrow gap from the base to the bay referred to as "the cut", and into the bay outside the seabase. The pilot told the harbor master he was going to start the engine as the plane was being towed through the cut, and the harbormaster held up a finger to indicated not yet and to wait a minute (see figure 1). According to the harbormaster, the pilot asked to start the engines several more times as the airplane was still under tow, and the harbormaster indicated to him to wait each time. Once the tow ropes were disconnected and the harbormaster moved out of the way, the pilot started the engine, which "went to full power" very soon thereafter. The sound of the engine starting and accelerating for takeoff can be heard on audio from a video taken before and during the accident. About 10 seconds elapsed between when the sound of the engine starting is heard and the sound of the engine power increasing is heard. The engine continues to run at high power throughout the takeoff and impact sequence.

The airplane began its takeoff run with the wing flaps retracted from the bay toward the northwest immediately after the engine power increased. Video of the takeoff showed the airplane accelerate across the water for about 60 seconds before it porpoised up and down two to three times and the nose rose steeply out of the water (see figure 2). The airplane then rolled to the left and the left wing impacted the water. The airplane subsequently spun to the left and turned about 180°. The nose entered the water and the airplane subsequently started to sink. The pilot-rated passenger was able to egress the airplane; the other two occupants were extracted by first responders who saw the accident and responded immediately to the airplane.

The pilot-rated passenger recalled the pilot verbalizing that the flaps were down and the trim indicator was "in the green" prior to starting the takeoff.

PERSONNEL INFORMATION

Pilot

The pilot, who was the owner of the airplane, was issued a third class Federal Aviation Administration (FAA) medical certificate on May 30, 2016, with limitations for corrective lenses and the use of hearing amplification. The certificate was not valid for any class after May 2017. At the time of the examination, the pilot reported 33,467 total hours of flight experience, with 30 hours civilian flight experience in the previous 6 months.

An FAA Form 8700-2, Comprehensive Medical Examination Checklist for a BasicMed medical certificate was found in the pilot's belongings. The checklist was completed; however, the checklist was not signed by a physician and no record was found that the checklist had been submitted to the FAA or that the BasicMed application process had been completed.

The pilot's flight logbook was recovered from the accident scene, but most entries were illegible due to water damage. One legible page contained a summary of flight time that indicated 33,309 total hours flight experience, 19,700 hours in single-engine airplanes, and 888 hours in single-engine seaplanes.

Pilot-Rated Passenger

The pilot-rated passenger told investigators he had about 3,000 total flight hours, 1,600 hours as a flight instructor, and about 150 hours in Lake LA-4-250 (Renegade) airplanes. He stated that he had provided the pilot with seaplane instruction and had conducted about 100 water landings in Lake Renegade airplanes. He also stated water takeoffs could be performed with the flaps retracted in the Lake Renegade.

AIRCRAFT INFORMATION

The elevator trim system is a hydraulic system. The hydraulic valves are opened and closed mechanically when the trim control is moved in the cockpit, which drives the hydraulic actuator located in the elevator which changes the position of the trim tab. There is a trim position indicator in the cockpit collocated with the trim control.

METEOROLOGICAL INFORMATION

WRECKAGE AND IMPACT INFORMATION

The wreckage was located about 0.7 mile northwest of the reported takeoff starting point. The airplane remained intact and came to rest in about 15 ft of water. The right wing was partially buried in mud under the water. The airplane was recovered 4 days after the accident and taken to a secure location for examination. Both left and right wing spars exhibited buckling. The right wingtip was bent upward into the right aileron and the fuselage exhibited buckling deformation immediately forward of the empennage. Continuity was verified between all control surfaces and the cockpit flight controls. The landing gear handle was in the UP position and the landing gear were found retracted. The flap lever was found in the UP position and the flaps were retracted.

The takeoff trim position indicator was near the neutral position and within the green band range for takeoff, and the takeoff trim tab was in a position close to or at its maximum up position. Continuity was verified from the Trim Tab to the indicator in the cockpit. The trim tab was in the full up position, and the trim control and indicator was near the neutral (no trim up or down) position on the indicator.

No preimpact anomalies were noted that would have prevented normal operation of the airplane or engine.

MEDICAL INFORMATION

The Fond du Lac County Medical Examiner, Fond du Lac, Wisconsin, performed an autopsy of the pilot. The cause of death was determined to be an anoxic brain injury due to near drowning. The results for toxicology testing performed at the FAA Forensic Sciences Laboratory were negative for all tested-for substances.

ADDITIONAL INFORMATION

The Airplane Flight Manual (AFM) for the Lake L-250 "NORMAL OPERATING PROCEDURES" states:

NOTE: Flaps are used for all takeoffs and landings.

Step 14 of the Before Takeoff checklist in the AFM also states: Wing flaps – DOWN.

During the wreckage examination, a printed checklist for a water landing and takeoff was found affixed to the instrument panel in a prominent location visible to the pilot. It stated in part, Flaps – Down.

The AFM also states,

WATER OPERATION – The maximum demonstrated wave height is 18" (trough to crest). This figure does not necessarily represent the limiting value for the airplane, which depends on the judgement of the pilot concerning airplane loading, wind conditions, wave height and form, and his own level of proficiency.

The FAA handbook for Seaplane operations, FAA-H-8083-23, states the following regarding the effects of water conditions on operations,

"Even relatively small waves and swell can complicate seaplane operations. Takeoffs on rough water can subject the floats to hard pounding as they strike consecutive wave crests. Operating on the surface in rough conditions exposes the seaplane to forces that can potentially cause damage or, in some cases, overturn the seaplane. When a swell is not aligned with the wind, the pilot must weigh the dangers posed by the swell against limited crosswind capability, as well as pilot experience."

According to an experienced Lake instructor pilot, a water takeoff with a 2 ft sea state is unadvisable unless the pilot is experienced. He also stated a rule of thumb taught to inexperienced pilots is to retard the throttle immediately during a water takeoff if the airplane starts porpoising and you feel one "thump" when the fuselage makes contact with the water. Experienced pilots should to retard the throttle immediately during a water takeoff if they feel 2-3 "thumps". He also stated that a takeoff downwind is never a good idea on the water, particularly in [the sea state present during the accident takeoff]. "A take off without flaps, downwind, in [the sea state present during the accident takeoff] is a disaster in the making."

NTSB Probable Cause

The pilot's failure to properly configure the airplane for takeoff and his decision to takeoff with a tailwind in unfavorable water conditions, which resulted in the airplane entering an aerodynamic stall and the pilot losing control.