Sorry to hear that your mum and dad are caught up in the current problems. Years ago, I used to work in aviation and still take a passing interest in it. As many of the routes in and out of Luton and Heathrow pass over the locality, it is rare that there is not an airliner or two visible. They don't cause much noise but the current silence is eerily noticeable. I shall just have to content myself with watching the Red Kites in the area.
If you've been watching the TV news it is likely that you have heard mention of Capt. Eric Moody who was in command of a BA 747 near Indonesia back in 1982. All four engines ingested volcanic ash and turned the aircraft into a glider. They did get them going again but they were so badly damaged that they were scrapped. It is rumoured that, being British, he paused during the engine re-light drill to take tea
Carruthers