Multiple failures of electrical systems forces emergency landing of air attack aircraft

On July 26 the pilot and the Air Tactical Group Supervisor had a close call in an exclusive use Aero Commander 690 while flying a fire in Idaho. Thanks to their close coordination and crew resource management they landed safely at the Rexburg, Idaho airport.

Below is part of the report that was filed:


On Thursday July 26th while flying on the Grassy Ridge Fire, Air Attack XXXX experienced an in-flight emergency requiring an immediate landing at Rexburg {RXE} Airport which was approximately 4 minutes flight time from the fire. The nature of the in-flight emergency was that the ATGS and Pilot started smelling the odor produced from burning wire.

The ATGS immediately turned off the AC unit, as it had a breaker trip 2 days earlier and first thought was that maybe that could be the problem. However within a minute the Door Indicator Light came on, the Pilot went to reset the switch and it immediately popped off again. Then the Pilots radio and intercom went out.

The decision was made to head to the nearest airport which was identified as Rexburg showing 4 minutes on the GPS. The GPS turned off and then came back on. The Pilot and ATGS went through the Electrical Emergency Procedures Check List and set up for a straight in landing on Runway 17 {RXE}. The ATGS notified Dispatch and the IC of the emergency situation in route to the airport. The ATGS due to the Pilots radio being out made the calls on 122.8 of the approach and landing.

Upon landing more things started to fail, the right “Gen Out“ light went on and a couple circuit breakers popped out. Once the plane landed the gear down warning started to sound. The aircraft was taxied to parking and the Pilot went through the shut down procedures, however the engines would not shut down. The ATGS held in the door activation switch and the pilot reset a couple of the breakers and the engines shut down.

The pilot and ATGS did a quick survey of the aircraft to insure there was no fire and no smoke was visible, just the strong odor of the burning wire. With all power turned off the aircraft was monitored while the Pilot and ATGS made calls to Dispatch and company owner and mechanic.

The Owner and Head of Maintenance arrived in Rexburg about 1830 and began to do an inspection. The initial finding was that the Pulse Light on the right wing tip had caused the control switch to “melt“. For some reason a breaker or fuse did not trip and it cause the wiring to start to melt. This caused other wires to also “fry“ which was the cause of the loss of the pilot radio and other items turning off and circuits to pop. The company is starting the process of going through the wiring trunk and repair the damage caused by the incident.