Judging GPS Receiver Reliability...

[Ironflight]

Perfection is an admirable goal John, and I salute those who strive for it. However, I have been in the aerospace vehicle flight test business all my life, and have yet to find the vehicle, system, machine, or piece of code that I would trust NEVER to fail. Make it idiot-proof, and someone will invent a better idiot.

Or better yet, give it to us Ops guys....and we'll figure out a way to break it! (I'm not saying that is a good thing....)

Paul

[OldAndBold]

Originally Posted by Ironflight

Perfection is an admirable goal John, and I salute those who strive for it. However . . .
Paul

Several years back, I inherited a embedded Java based flight display for a fighter aircraft photo recon pod. Both it and the system it was a part of were a nightmarishly bad design prone to frequent lockups and total system crashes. In particular, I knew that just three or four of the right button presses would lock up the system - not because the display software was wrong but because the rest of the system couldn't handle the inputs correctly. I tried to point this out to the manager but he objected saying that the pilot was supposed to know better than to press those buttons in that sequence. I felt bad for the poor flight crews that had to take that system out into the desert in Iraq at the beginning of the war and remember not to press the wrong buttons as they were trying to avoid SAMs.

The point is that there is a mindset in the (US?) aerospace industry now that thinks that it is OK and even unavoidable that the software occcasionally locks up or crashes. It is neither acceptable nor unavoidable nor even difficult to avoid. Perfect software? No. But highly fault tolerant? Definitely do-able. Like being able to detect and recover from a fault in between keypresses - should definitely be do-able.

When I started this thread I was expecting to find out that the GPS receivers were highly reliable and that almost noone had had any problems in flight. I am a bit suprised by the responses thus far.

(You should be able to tell that I am stalled waiting for a new R-710 to arrive...)

[Mel]

Unfortunately I think you are hearing from the "few". I've been flying with several different GPS systems since they became popular in the early '90s and have never had one "lock up".

[L.Adamson]

Originally Posted by Mel

Unfortunately I think you are hearing from the "few". I've been flying with several different GPS systems since they became popular in the early '90s and have never had one "lock up".

Owned three aviation data-based moving map Garmins, and one non-aviation Garmin model since 1993. No lockups either. The last is a 296, which gets more use in a ground vehicle, but still no lockup.

[OldAndBold]

Originally Posted by L.Adamson

Owned three aviation data-based moving map Garmins, and one non-aviation Garmin model since 1993. No lockups either. The last is a 296, which gets more use in a ground vehicle, but still no lockup.

OK, good, like I said I am just trying to get a feel for things. Thanks.

[RV8iator]

I had a brand new Garmin 496 die on me. Called the distributor down on the Gulf Coast and they had me try a few things and then said send it back. They replaced it with a new one as soon as they received my broken unit. It had about 5 hours on it and when it would switch on, the screen had a vertical stripe and it was frozen.
I also have a GXS250 and a map..