Newps wrote:

Whole deal might last 10-15 seconds but it
seems like forever if you have a lot of traffic. No data is lost in
this process.

Do it the way the phone company does. Everything runs off of battery. If
the commercial power feed fails and the diesels have to kick in, there's
no discontinuity of service.

Now, every once in a while a substation goes down and nobody notices
(happens once in about 50 years or so). In that case, somebody loses
service after about two days. Think ATC would notice a problem by then?

There is one practical difference. The phone company is running off of
48 volt DC, and ATC is using standard AC (I presume). Still shouldn't be
a problem for a decent engineer.

George Patterson
The optimist feels that we live in the best of all possible worlds. The
pessimist is afraid that he's correct.
James Branch Cavel