Aviation Accident Summaries

Aviation Accident Summary ANC19LA036

Chattanooga, TN, USA

Aircraft #1

C-GAFT

Stoddard Hamilton GLASAIR II

Analysis

While enroute, during a cross-country flight, the experimental amateur-built airplane experienced a complete failure of the electrical system, which resulted in a complete loss of engine power. The pilot subsequently made an off-airport landing in a meadow, however during final approach, the airplane aerodynamically stalled, landed hard, bounced, and nosed over. The airplane was equipped with a backup electrical circuit system which was labeled the essential bus. The pilot reported that during the accident sequence he failed to switch the power supply to the backup power. It is likely that the primary electrical system that the pilot installed failed for unknown reasons, and if he had switched to the secondary electrical system, the airplane would have likely restored electrical power.

Factual Information

On July 17, 2019, about 1540 eastern daylight time, a Stoddard Hamilton Glasair II FT experimental amateur built airplane, C-GAFT, made an emergency off-airport landing following a loss of electrical and complete loss of engine power about 30 nautical miles northwest of Chattanooga, Tennessee. The pilot sustained serious injuries, and the airplane sustained substantial damage. The airplane was registered to the pilot and was operated under the provisions of Title 14 Code of Federal Regulations Part 91 as a visual flight rules personal flight. Day visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed. The flight originated from the Cleveland Regional Jetport (RZR) Cleveland, Tennessee, about 1500. According to the pilot, while in level cruise flight the electronic flight instrument system and electrical system failed, followed by a complete loss of engine power. He added that, he went through the airplane's checklists and systems, but was unable to restore engine power. He attempted to glide to a nearby field for an emergency landing. He added that, by the time he was over the selected meadow, he did not have enough room for a straight in landing. He then maneuvered the airplane between a tree line to land in the next meadow. During the approach, the airspeed diminished, he pitched down for speed and tried to flare for landing, and the airplane aerodynamically stalled prior to touchdown. Subsequently, the airplane landed hard, bounced, one wing caught the ground, and the airplane nosed over. The pilot was also the mechanic who performed regular maintenance and inspections and had installed the following systems on the airplane. The ignition system consisted of an E-Mag Electronic Ignition with one E-Mag and one P-Mag; (the right P-Mag had been removed and EFII ignition coils were installed). The manufacture notes that, the E-Mag must have power supplied to it in order to properly function, and that the P-Mag has an emergency built-in backup alternator system that will still operate and produce spark when the engine is above 900+ RPM, and sometimes less. Both the E and P models need outside electrical power to start. It is also stated by the manufacturer that even a low battery that barely "bumps" the starter motor or can only "click" the solenoid will likely have enough energy to power the ignition for prop starting. The carburetor was replaced with an EFII electronic fuel injection system, and a VP-X Pro solid state electrical system was installed as the primary electrical system. The fuel injection system and both electric fuel boost pumps were supplied power through the VP-X Pro system. The owner had wired in a backup power supply/bypass system that supplied power directly to the essential electrical bus panel. The essential electrical bus panel was used to supply power from the battery to the fuel system, ignition system, engine control unit, and propeller system. The pilot further stated that, during the accident sequence he forgot to switch the power to the essential bus backup system. The essential bus is actuated by a switch that is mounted next to the master switch on the cockpit panel. The pilot added that, if he had switched to the backup essential bus, the accident likely would not have occurred. A Federal Aviation Administration aviation safety inspector completed a check of the battery and stated that it had a full charge and no anomalies were noted. He added that during the examination he did not find any burnt wires but did locate 1 AMP fuses that had blown. A NTSB aircraft systems engineer tested the solenoids, and both checked operational. A visual examination of the VP-X Pro revealed impact damage to the J10 and J12 connectors and a test of the unit was not accomplished. The reason for the failure of the primary electrical system that the pilot installed was undetermined based on the available evidence.

Probable Cause and Findings

The pilot's failure to switch to the secondary electrical system after the primary electrical system failed for unknown reasons.

 

Source: NTSB Aviation Accident Database

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