What happened
Three Piper J3 aircraft departed from an airport situated in a valley characterized by nearby higher terrain. At the time of departure, the density altitude was approximately 3,000 feet. The flight path for all three aircraft involved turning toward rising terrain composed of canyons, lower finger ridges, and a higher main ridge.
The first aircraft, operated by a solo pilot, successfully climbed above the terrain elevation and turned downwind. The second and third aircraft, each carrying a pilot and one passenger, attempted to follow similar flight paths over the rising terrain.
The second aircraft, which was operating at gross weight, encountered descending air that forced the plane into the trees. The pilot of this aircraft reported no mechanical issues with the engine or the airplane itself. No fatalities were reported in the source text, though the impact involved trees.
Findings
Investigation of the second aircraft revealed it was equipped with a cruise propeller, an modification that increased cruise speed but simultaneously decreased the aircraft's rate of climb.
Additionally, although the pilots had been briefed on alternative departure routes that would have avoided the need for an immediate climb over rising terrain, those routes were not utilized during the flight.