I reckoned that the coming of INS was the greatest single advance in aviation in my lifetime, almost like the invention of the chronometer for the old time seafarers, sure GPS gets it's information in a more modern and different way, but it doesn't really present you with anything that we couldn't get from INS, just does it a bit more precisely, I guess, and the colours and maps are pretty, too !
Couldn't be bothered re-programming the panel mounted GPS for some info. the other day, so pulled a handheld from my pocket - Sextants on 707's and now TWO GPS's - on a Microlight !! ( LSA to the USA readers ) how the World has changed.
A colleague once remarked that the wheel had turned full circle, some of the old ( younger than I am now, but they seemed old then ) Captains that we started with couldn't fly an instrument letdown and approach to save their lives, literally ( well, some of them ) but pop out of cloud and say " the runways' over there - Sir " ( of course ) and they would straighten up and fly an immaculate visual approach to a copybook landing, but our students of the time, brought up by Mr. Microsoft and his Flight Sim. could probably fly an instrument approach better than we ever would, but then the had to put a real aircraft back on to the real Earth - and had difficulty.
I do wonder how some of them will cope one dark and dirty night when all the fuses have blown on their Yuppie, T.V. type instruments ?
( of course, you're going to tell me it will never happen. Yeah, right ! )
We were also told that the failure rate of the INS was about one in a Zillion hours - I had two fail on a 747 within 10 minutes of each other, dumped fuel and was on the ground smartish, to be criticised by the local outstation engineer for not returning to Base. Fat chance, how long was the third one going to last, and I didn't fancy a possible ILS in 200 metres with only the standby A.H. and compass. I'm on the ground, fix it Sunshine, sorry about your Saturday night party !