Accident Overview
On July 22, 2022, at about 1330 Pacific daylight time, a Piper J3C-65 airplane, registration N3666K, was substantially damaged during an accident near Huntington Beach, California. The pilot sustained minor injuries. The flight was conducted as a banner towing operation under Title 14 Code of Federal Regulations Part 91.
Flight Path and Events
The pilot reported departing Compton-Woodley Airport (CPM) in Compton, California, and heading west toward the shoreline. After passing the intersection of Interstates 91 and 110, he switched to the right fuel tank. He then proceeded to Zuma Beach, where he reversed course and headed south toward Laguna Beach. Somewhere between Long Beach and Los Alamitos, he switched back to the left fuel tank. After passing the Huntington Beach pier, the engine lost all power. The pilot turned toward the beach but chose to land in the water, resulting in substantial damage to the wings and fuselage. He egressed the airplane unassisted.
ADS-B Data
Automatic dependent surveillance-broadcast (ADS-B) data from the Federal Aviation Administration (FAA) corroborated the pilot's description. The airplane began its takeoff roll at about 10:46 and flew westbound at about 1,200 ft mean sea level (msl). It crossed the I-91/I-110 intersection at 10:54, reached the shoreline at 11:02, then turned right and followed the shoreline north, about 2,000 ft offshore. The airplane descended to about 500 ft msl and remained at that altitude. At 11:45, near Zuma Beach, it turned 180° and followed the shoreline south, making a 3.5-nautical-mile orbit near Malibu Beach. It arrived near the Huntington Beach pier at 13:28. At 1330:10, while about 1 mile south of the pier, the airplane began a descent and turned left toward the shoreline. The last data point at 1330:33 showed the airplane at 0 ft msl, about 1.25 miles south of the pier. The flight time from the I-91/I-110 intersection to the start of the descent was about 2 hours 36 minutes.
Witness Accounts
Multiple witnesses on the beach reported that the airplane descended rapidly with no indication of engine operation or loss of control. The airplane struck the water nose-first and came to rest upright. The pilot egressed unassisted.
Postaccident Examination
On-scene examination revealed no fuel in the right fuel tank and no fuel leakage after the airplane was recovered from the water. A video from a local news agency showed the airplane, towing a banner, descending and impacting nose-first, with the fuselage submerged and wings floating. The operator stated the banner was 40 ft by 80 ft and weighed 55 to 60 pounds.
Immediately after the accident, samples from the gascolator and left fuel tank were clear and debris-free. No fuel was present in the right tank, and no evidence of fuel escaping from the engine or internal systems was found. A follow-up examination found the engine secured to its mounts, with saltwater inside. About one quart of oil remained in the engine case. No metal debris was in the oil pan strainer, and no overheated bearings were noted. There was no damage to intake runners or exhaust stacks. The crankshaft rotated freely after cylinder removal, though sand and saltwater corrosion were present in all cylinders, with no damage to cylinders or valvetrain. Both magnetos showed saltwater corrosion, but all ignition leads sparked after cleaning. The fuel strainer contained clean fuel. The carburetor accelerator pump functioned normally. No mechanical malfunctions or failures that would have precluded normal operation were found.
Fuel System and Weather
The pilot's operating handbook indicated the airplane had a Van Wagner fuel system with two 18-gallon tanks and a 2-quart header tank for each. The fuel selector/shut-off valve was near the front seat. Standard fuel consumption was 10.0 gallons per hour at 75% power and 8.8 gallons per hour at 65% power. The operator reported that the pilot calculated a burn rate of about 7.4 to 7.6 gallons per hour.
A fuel sample from the airport pump at CPM showed no contamination. The airport manager stated the pilot requested fuel for the fleet, including N3666K. The person who refueled the airplane reported that only 0.6 gallons could be added because the tanks were nearly full.
Weather at John Wayne/Orange County Airport, about 8 miles northeast, recorded at 1353: temperature 79°F, dew point 61°F. According to the FAA Special Airworthiness Information Bulletin on Carburetor Icing Prevention, these conditions were conducive to serious icing at glide power.