High
vlsrotate,
Welcome to PPRuNe! Good question, and sorry no one has yet risen to the challenge. Afraid I'm not going to be much help either.
However, just want to point out that, even when the a/c is fitted with two radar transceivers (as mine were), they are in close proximity and there's only one dish antenna. I once got struck bang on the nose on an approach into Bilbao (no, that wasn't the co-pilot losing his temper
). The result was a fist-sized hole in the radome and the failure of both TRx boxes.** I can't remember if the dish itself was damaged, but if the airspeed had been higher I suspect it would have been.
So maybe the case in your sister airline was fortunate. Perhaps one of our resident engineers will comment.
I don't know the probability of a TRx failing
spontaneously after despatch. Being equipped with two obviously reduces the probability of the a/c being unable to despatch because one TRx has failed when away from a suitable maintenance base - assuming your MEL is representative.
**
EDIT
On reflection (it's been many years...), the non-operating TRx
may not have been damaged. A new radome was sent by road from Madrid (my having declined the ground engineer's offer to repair the rain-soaked damage to its honeycomb-type material with speed tape
). But I think we
may have despatched the following day with one serviceable TRx, and I don't recall a replacement TRx being fitted.
(BTW, FWIW the a/c was an A320 and no other systems had been affected by the lightning strike, so the approach had been continued without further incident. EFIS, FMGC and EFCS continued operating without interruption.)