<<The current procedures also cause far more problems for both ATC and every other aircraft in the area, for in unnecessarily lengthening the time the aircraft in difficulties remains airborne, they inconvenience and delay all other traffic in the area much longer than they should>>
In 30+ years working Heathrow traffic I don't think I experienced more than a handful of true radio failures, ie those that lasted until after landing. Mostly the pilots did what we expected and we simply carried on with the landings allowing slightly larger-than-usual gaps around the RT failure so there was no serious delay. We had to assume it was simply radio failure otherwise the pilot would have squawked something more appropriate. One assumes that in a real emergency they'd come straight in - and in a radar-controlled environment such as the London TMA ATC is perfectly equipped to deal with such action.
What always worries me - especially in the context of the current thread - is that ATC has NO procedures for the event of total RT fail at their end. There are backup RT facilities at every position, but if they fail you're in bad trouble and you can't do much apart from sit back and watch what happens - and watching two a/c at the same level quietly heading straight for each other which you can't talk to is far more effective than Exlax. We can't squawk "RT Fail" and we can't use the outside phone to ring pilots' mobiles!! ("Directory enquiries, which name?" "Er.. can you give me the number for the BA 757 just turning inbound at Bovingdon?"). In my, albeit limited, experience of such events pilots sensibly reverted to the previous frequency or another ATC unit nearby... resulting on the guy on the "failed" sector suddenly receiving 20 phone calls asking "what do I do with the Midland/ Speedbird/ United?" etc.
Hey - it's great to be retired!!!