Light Transport; Low Wing; 2 Turboprop Eng
Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Aircraft Equipment Problem Less Severe; Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Weather; Aircraft; Human Factors
While training a third party student I was making radio calls on CTAF at GUC. I had previously verified that the radio I was using (Comm 1) was operative. After several approaches (both to missed and to landings); during which I continued to make calls on CTAF; we ended up head to head on the runway with another airplane. Both aircraft were fully stopped while still a great distance from one another (probably more than 1000 feet). I made another call on CTAF and we taxied back to the FBO to find out what happened.We were informed that no one had heard our calls; so I went back out to the airplane in order to check the radios. I could not discern why Comm 1 was inoperative; so I wrote it up first and then called Maintenance. Maintenance Control asked the usual questions; including checking the volume and making sure the radio was on (both these things I had already checked); and then suggested I check the circuit breaker. The breaker was popped so I reset it as per Maintenance Control's directive and I cleared the write up according to the instruction of the Maintenance person I was talking to.Asking for frequent radio checks from the FBO are the only way I can think of to avoid this happening again. It was very hot (over 100 degrees F) in the cabin; despite having the temp control set to full cold. This might have had something to do with the circuit breaker popping.I am certain that for most of that training flight; we were hearing (and were heard on) CTAF. It was just right at the end when something happened.
Instructor pilot; practicing landings with a student and using CTAF procedures; finds himself nose to nose with another aircraft on the takeoff roll. After stopping with room to spare it is discovered that Comm1 had failed due to a tripped circuit breaker.