History of Flight
On January 17, 2017, at 1055 Pacific standard time, an experimental amateur-built Harmon Rocket, N275JS, impacted terrain following a total loss of engine power during the initial climb from Corona Municipal Airport (AJO), Corona, California. The airplane was operated under Title 14 Code of Federal Regulations Part 91 as a local personal flight. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated at 1026.
According to witnesses, the airplane initially took off from runway 25, then landed on runway 07 and immediately departed. After reaching about 100–200 ft above ground level (agl), the engine lost power. The airplane made a steep turn back toward the airport and collided with terrain, coming to rest on flat, soft vegetation on airport property, about 1,650 ft from the departure end of runway 07.
Data from an Advanced Flight Systems AF-4500s multifunction display (MFD) showed that the airplane circled over Lake Mathews southeast of the airport, returned to AJO, and performed three practice takeoffs and landings on runway 25. It then conducted a 360° turn west of the airport and a touch-and-go on runway 07. The airplane became airborne at 1052:29 and climbed to about 770 ft mean sea level, at which point fuel flow dropped from about 20 psi to less than 1 psi. Engine rpm and exhaust gas temperature decreased drastically, consistent with a total loss of engine power. The airplane began a right turn about 1052:34 and impacted terrain at 1052:49.
Pilot Information
The front-seat pilot, owner and builder of the airplane, held a private pilot certificate with ratings for airplane single- and multi-engine land and rotorcraft, as well as a repairman experimental aircraft builder certificate. He was issued an FAA third-class medical certificate in October 2015 with a limitation for near vision glasses. He reported 2,000 total hours of flight experience on his most recent medical application.
The rear-seat commercial pilot held ratings for airplane single- and multi-engine land and sea; rotorcraft-helicopter; instrument airplane; and a flight instructor certificate. His most recent FAA third-class medical certificate was issued in January 2017 with a limitation for near vision glasses. He reported 20,000 total hours of flight experience, with 200 hours in the previous 6 months. It could not be determined who was acting as pilot-in-command.
Aircraft Information
The Harmon Rocket was a low-wing, single-engine experimental airplane constructed by the owner and completed in 2010 with serial number 0471. The last condition inspection was performed by the owner in October 2016, noting a total time in service of 90.71 hours. The airplane was equipped with a Lycoming IO-540-C4B5 engine, serial number L-5545-48, modified for experimental use. The engine was overhauled in May 2009 by Aircraft Engine Specialists.
The fuel system was a gravity-fed design with metal wing tanks, a selector valve, electric fuel pump, transducer, gascolator, engine-driven fuel pump, and a Bendix RSA-5AD1 fuel servo (part number 2524213-1, serial number 6507-T) manufactured in 1977. Maintenance records indicated the fuel servo was noted as serviceable during the engine overhaul; no other maintenance records for the servo were found. The servo retained its original black data plate, indicating it had not been overhauled since manufacture. Per Precision Airmotive, internal parts appeared original, and all regulator-side parts are required replacement items at overhaul; the servo should have been overhauled every 12 years per a 1991 calendar requirement.
Fuel Servo Examination
During postaccident examination, the fuel servo was removed and tested. When fuel was plumbed to the servo, no flow to the outlet was obtained. After replacing the accident servo with an exemplar, fuel flowed freely. The engine, fitted with an exemplar servo, started and ran successfully at various power settings.
Disassembly of the accident fuel servo revealed that the valve stem was separated from the regulator valve (ball). The regulator housing safety wire had a crimp stamped "AKB." When the accident servo was reassembled using the exemplar's regulator section, fuel flowed normally. Conversely, installing the accident regulator section on the exemplar servo prevented fuel flow. No other anomalies were found in the fuel system components examined, including the fuel selector valve, electric fuel pump, transducer, gascolator, and fuel manifold.