On Tuesday, 3 August 2021, the Commercially rated pilot departed Whiteman Airport (WHP) for Lake Isabella to perform some water landings. The pilot received his airplane single-engine sea rating one week prior on 27 July 2021 and had fewer than 20 hours in the accident aircraft. The pilot stated that he was “unable to takeoff from the water” at which point he decided to taxi up a boat ramp on the southeast side of the lake. The pilot stated that he attempted to “takeoff from the boat ramp” since he was unable to takeoff from the water.
As of August 4th, Lake Isabella is located at 2,534′ elevation, down 10′ from a high of 2,545′ on May 23rd. The lower lake level exposed the cottonwood trees that litter the bottom of Lake Isabella and were not completely removed when the lake was flooded. On the day of the accident, the temperature was 40C (104F) and the pressure was 29.80 with a density altitude of 5,970′ at the time of the accident.
The closest reporting METAR is KTSP at ~30NM.
KTSP 032215Z AUTO 31016G22KT 10SM CLR 34/05 A3013 RMK AO2
METAR KBFL 032154Z 29008KT 7SM CLR 36/07 A2990 RMK AO2 SLP118 T03610072
A weather station 3NM away reported 40C (104.5F) and 29.80 at the time of the accident with wind from the west at 10-15MPH.
The Lake Aircraft owners manual only specifies a takeoff performance for the LA4/200 (200HP model). The performance listed is 650’ for takeoff from a dry, paved surface at sea level on a standard day. Extrapolating the takeoff distance using an accepted ‘rule of thumb’ of an additional 15% for each 1,000’ of density altitude would require 1,527’ for takeoff. The measured distance of the boat ramp the pilot attempted a takeoff from is 237’.