In Reply To:
I understand the fear that since they don’t control the system, the satellites could be “turned off” or the accuracy degraded without their knowledge,
I’ll bet that, as soon as the shooting hostilities begin in Iraq, we’ll start getting lots of RAIM warnings as the U.S. military intentionally degrades the GPS constellation signals to prevent others from using them for guidance. We probably won’t be doing much GPS-guided navigation for the duration of the shooting war, and I’ll be VERY surprised if we get ANY sort of NOTAMS about it beforehand. (Better brush up on your VOR-to-VOR and airways navigation and plan your IFR trips to airports that don’t have GPS-only or GPS in lieu of DME or ADF requirements! Also, how many of us actually ask FSS during briefings to check RAIM availablity at our destination ETA before launching?) If I was a European government, I wouldn’t put up with that uncertainty when my commerical and private air traffic depended on it! It relies too much on the good will of the U.S. gov’t, something that is in extremely short supply these days given the amount of political strong-arming our gov’t is doing right now!
Hypothetical example: If France, for instance, currently allowed widespread use of GPS-dependent navigation, the U.S. could have threatened to block or degrade the GPS signals, causing all sorts of air navigation issues in French airspace, in order to make France side with us on the Iraqi UN security resolution . Now, pick ANY other EU country we were trying to bully into compliance with our foreign policy…
I’ll bet that as soon as the EU gets their own GPS system up and running, they’ll allow GPS navigation, but you’ll probably have to have a box that receives different frequencies.