Incident Overview
At 2059 mountain daylight time, a lightning strike caused a power outage in the air traffic control (ATC) tower at an airport. Electrical power was subsequently restored, but some equipment, including the radar computer and voice recorders, remained inoperative for a period.
Sequence of Events
At approximately 2121, a Cessna 402B, registration N25BH, contacted ground control (GC) and was cleared to taxi from the executive hangar to runway 28R for takeoff. About one minute later, a Piper PA-34, registration N3408Q, contacted GC and was cleared to taxi from the regional hangar to the departure runway. Dark night conditions and rain prevailed at the time.
As the Cessna proceeded eastbound on the parallel taxiway to runway 10L/28R, the PA-34 was exiting an adjacent ramp area where other aircraft were parked. The two airplanes converged at a taxiway intersection, but neither pilot saw the other aircraft in time to avoid a collision.
Damage
The Cessna's left wingtip/fuel tank was slashed open by the PA-34's right propeller, resulting in a fuel spill and substantial damage to the Cessna's left wing. The PA-34's right wing received minor damage.
Investigation Findings
Investigation revealed that GC did not provide any advisories after the initial taxi clearance. An alarm, caused by an equipment failure, distracted the tower controller(s), who never visually identified the PA-34.