Accident Summary
On January 31, 2015, about 1445 central standard time, an experimental amateur-built Rotorway Exec 162F, registration N162RB, sustained substantial damage during a hard landing following an emergency autorotation near Seadrift, Texas. The pilot and his passenger were not injured. The helicopter was operated under 14 CFR Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed. The local flight originated from Port Lavaca, Texas, about 1420.
Pilot's Account
The pilot reported flying at approximately 300 feet above ground level while returning to Port Lavaca after a 25-minute sightseeing flight. The LOW ROTOR RPM horn sounded, and the engine lost power. The pilot initiated an autorotation and selected a landing area. He arrested the rate of descent, but the helicopter retained excessive forward speed to land vertically. While maneuvering the helicopter into tall, heavy grass about 8 feet above the ground, main rotor speed decreased below the minimum safe rpm. The pilot stated the helicopter was still moving forward at high speed, and it landed hard, tearing off the landing gear.
Engine Modification and Previous Issues
According to the pilot, the stock Rotorway engine had been highly modified. An after-market Full Authority Digital Electronic Control (FADEC) system, designed specifically for the engine, had been installed. The FADEC system comprised two separate and redundant Engine Control Modules (ECMs). On one prior occasion, the engine failed to start after a brief flight. The pilot traced the issue to a fault in the No. 1 ECM. Both ECMs were sent to the manufacturer for examination and testing; no problems were identified, and they were returned. The pilot completed four additional uneventful flights totaling more than 3 hours before the accident flight.
Post-Accident Examination
After the accident, the pilot examined and tested the ignition system, as the manufacturer was no longer in business. With both ECMs on, the engine started and ran normally. When the No. 1 ECM was switched off, the engine continued to run on the No. 2 ECM. However, when the No. 1 ECM was switched back on, the engine quit. The only way to start the engine was to engage the No. 2 ECM and leave the No. 1 ECM off. Every time the No. 1 ECM was switched on, the engine would quit. The pilot swapped the wiring harnesses and confirmed that the problem followed the No. 1 ECM. He determined that the fault lay solely in the No. 1 ECM.