Accident Details
On January 9, 2021, at approximately 1000 central standard time, a Robinson R44II helicopter, registration N322SH, was substantially damaged during an accident near Albany, Texas. The helicopter was operating under Title 14 Code of Federal Regulations Part 91 as a hog hunting flight. The pilot and two passengers were not injured.
According to the pilot, it was the second flight of the day. After an uneventful first flight, the helicopter returned to the airport for refueling and to pick up new passengers. While the passengers were boarding, a rifle was dropped on the dashboard, causing the alternator switch, master switch, and clutch switch to turn off. After the pilot turned the switches back on, he conducted a hover power and final systems check. The subsequent takeoff was uneventful.
When the helicopter reached an altitude of 120 feet above ground level, the engine sputtered once and then lost complete power. The pilot initiated a left-turning autorotation toward a field. During the descent, he increased throttle, but the engine did not respond. The helicopter struck trees before landing hard on a small mound of dirt, coming to rest nose low. The main rotor blade contacted and severed the tail boom.
Video Evidence
Video of the accident flight began with the helicopter on the ramp, the engine running, and the magneto key apparently in the OFF position. Additionally, when the pilot shut down the helicopter after impact, the key's position did not appear to change, despite the pilot's fingers touching it.
Postaccident Examination
During a postaccident examination, the airframe and engine were prepared for an engine run. The engine started normally and idled briefly, after which a magneto check was performed. Engine rpm decreased when the key was turned to the left magneto position, but rpm remained unchanged when the right magneto was selected. When the key was moved to the OFF position, the engine continued running. Manipulating, jiggling, or even removing the key from the ignition switch did not stop the engine.
The engine was shut down, and electrical continuity was verified from the ignition switch to the magnetos. The magneto grounding wires appeared properly secured; after disconnecting them, pulling and manipulating them revealed no anomalies. The grounding wires were tested with a volt/ohm meter and functioned normally. After reinstalling the grounding wires for each magneto, the engine was restarted and operated normally through several magneto checks.
The magnetos were removed from the engine. Their caps were removed, and no obvious anomalies were noted in the internal components. The ignition switch was also removed and disassembled, with no anomalies found.
The magnetos underwent a functional bench test and disassembly. During the bench test, the magnetos were heated to 190°F and performed normally. Disassembly revealed no anomalies with the E-gap, contact settings, condensers, coils, or distributor gear timing that would have prevented normal operation.
Checklist Reference
In the Robinson R-44II Pilot Operating Handbook, the "STARTING ENGINE AND RUN-UP" checklist includes: "Ignition switch…Prime, then Both," and "Mag drop at 75% RPM….7% max in 2 seconds." Both checklist items involve manipulating the ignition key prior to takeoff.