What was found
(CAN) FLIGHT CREW REPORTED A "BANG" SOUND IN THE CABIN, FOLLOWED BY VIBRATION IN THE FUSELAGE THAT LASTED FOR A SHORT PERIOD, AND SUBSIDED. NO IMMEDIATE ACTION WAS TAKEN. UPON ARRIVAL AT DESTINATION, IT WAS FOUND THAT THE ELT ANTENNA HAD BROKEN APART. THE ACFT DEPARTED ON A SPECIAL PURPOSE FLIGHT PERMIT, TO A MAINTENANCE FACILITY AND HAD A SERVICEABLE ANTENNA INSTALLED BEFORE RETURNING TO SERVICE. SUBSEQUENT TO THIS EVENT, THERE WAS AN IDENTICAL EVENT ON A DIFFERENT ACFT, OPERATED BY THE SAME OPERATOR, WITH THE SAME ANTENNA.