Bit of verbal diarrhea... but a bit more aint going to make a lot of difference...
During the mid nineties I was involved in bringing 5 ex-RCAF (CC-117) Falcon 20's onto the UK civil register. Three of these aircraft had previously been used for transport work and the other two for Electronic Warfare training. The transport variants were fitted with a detachable panel at the bottom of the fin. This panel carried a 121.5 / 243 /406(?) self powered Crash Locator Beacon; essential equipment given the RCAF operating environment in the wastes of the Arctic.
Deployment of the panel was initiated either by the crew and a switch in the cockpit, or in the event of a crash, by one of 5(?) Vacuum Crash switches, three along the lower fuselage and one in each wing tip. Operation of any one of these switches would deploy the panel and set the CLB to transmit. The boxes involved had been removed when the aircraft were retired but the activation mechanism was still in place...
As the Avionics Lead on the mod program, initially this and other role equipment wiring left me head scratching because the wiring diagrams for the said role equipment were 'not available'... but since we were going to remove all unidentifiable role equipment wiring it didn't matter too much. But the detective work was fun!
To the point however... I have often wondered why aircraft manufacturers don't design in something similar into modern airframes... an automatically deployable floating panel carrying a 406MHz ELT... ELT's are OK but once the aircraft submerges thats it... finito.
I always thought my former employers positioning of the required ELT was a bit stupid... the antenna was located forward of the tailcone at the base of the fin, but the ELT Transmitter was in the tail cone itself, the two connected by a length of RG-400 coax... in the case of a land crash the tailcone tends to separate from the rest of the airframe, thereby removing the Antenna from the transmitter... oops?