Accident Details
Probable Cause and Findings
The pilot’s decision to perform a takeoff with an overweight float-equipped airplane, which resulted in diminished climb performance.
Aircraft Information
Registered Owner (Current)
Analysis
On September 22, 2019, about 1630 Alaska daylight time, a float-equipped Piper PA-18, N7071B, was substantially damaged when it was involved in an accident near Beluga, Alaska. The private pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
The pilot stated that, on the day of the accident, he and the passenger harvested a moose on a small lake that he estimated to be 750 ft in length and decided to use the float plane to shuttle the meat to their hunting camp on another lake. Before loading the meat, the pilot flew multiple passes over the small lake and observed no hazards. He then performed a confined area landing and a practice takeoff without the load to assess the hazards and wind conditions. He observed light and variable winds from 3 to 8 knots and no problem taking off within the short distance. The passenger stated that there was a headwind during the practice takeoff and no wind after the accident, and they loaded a portion of the meat in the belly pod and the floats. The pilot stated that he was experienced at estimating meat weight and that the airplane’s takeoff weight was below the maximum gross weight of 1,760 lbs.
According to the pilot, there were no known mechanical issues with the airplane and the runup was normal. He conducted the takeoff from the lake with one notch of flaps extended. At 40 mph indicated airspeed, he extended another notch of flaps, and the floatplane successfully lifted off the water but was unable to climb. The pilot and passenger stated that they did not observe or hear any abnormal engine indications. The airplane descended to the ground beyond the lake, the right float and wing impacted the ground, and the airplane sustained substantial damage to the fuselage and right wing.
The night of the accident, the pilot stated that he overloaded the airplane with the moose meat and was forced to land after takeoff; he later stated that he did not know what caused the lack of climb performance, but “maybe it was a lack of engine power.” The pilot provided the estimated weights as: crew 365 lbs, fuel 78 lbs, meat in belly pod 60 lbs, meat in floats 50 lbs, and survival bag 9 lbs. The total estimated weight was 1,716 lbs, and the allowable maximum gross weight of the airplane was listed as 1,760 lbs in the airplane’s most recent weight and balance document. The passenger stated that there were no mechanical issues with the airplane and that the only abnormalities he observed during the takeoff were the lack of climb performance and the engine going quiet immediately before impact.
Postaccident examination of the engine revealed that the engine was intact with no loose lines, leaks, or impact damage. Engine control continuity was established. The propeller was attached and turned smoothly by hand, and the blades were undamaged. The ignition harness and spark plugs were intact. A fuel sample obtained from the fuel filter was consistent with avgas and free of contamination. There were no abnormalities noted in the air intake or exhaust system. During a test run, the engine was started and advanced to 2,300 rpm with no anomalies noted.
The investigation did not obtain the actual weight of the airplane’s contents due to the remote location of the accident.
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# ANC19LA054