DA40 Diamond Star
Flight Crew Multiengine; Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Commercial
Flight Crew Last 90 Days 30; Flight Crew Total 250; Flight Crew Type 160
Communication Breakdown
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR
Aircraft Equipment Problem Dissipated; Flight Crew Overcame Equipment Problem
Aircraft
On an IFR flight; whenever we transmitted on 133.600 MGhz; our ELT would start going off. Even though the ELT transmits on 121.500; the signal was so strong it could be heard on all frequencies on both of our aircraft radios and a handheld radio that I had. Before we realized the ELT was blocking all our radios; we squawked 7600 because we could no longer hear ATC. Once we realized the ELT was causing the problem; I reset it and re-established contact with ATC. Every time we had to transmit; the ELT would sound off again; forcing me to reset it over and over. Finally when we got transferred to a different approach; the ELT stopped causing problems.I called our maintenance and they said that once in a blue moon; transmitting on certain frequencies causes the ELT to trigger. On our return flight we once again had to talk to center on 133.600 but the ELT did not sound off this time.
The reporter stated that the ELT sounded off only when he keyed the mic and it affected all the radios in his aircraft only. The only way he was able to communicate using frequency 133.600 was to use the reset button on the ELT. The reporter stated he communicated with other aircraft and they did not hear any interference. The reporter stated that he did not know the brand of the ELT he was using. He also stated that Maintenance checked it out and could not find any discrepancy with the unit.
A Diamond DA-40-180 pilot reported that while flying whenever they transmitted on frequency 133.600 MGhz (Atlanta Center) the Emergency Locator Transmitter would start going off blocking all frequencies.