> Maybe if the stealth plane was 50,000ft or lower, but considering comercial traffic usually flies up to 39,000ft, and some private traffic at 45,000ft, you pr

> Maybe if the stealth plane was 50,000ft or lower, but considering comercial traffic usually flies up to 39,000ft, and some private traffic at 45,000ft, you probably won't find stealth aircraft below 50,000ft. F-117 service ceiling was 45,000 ft according to Wikipedia - B-2's is 50,000ft. Ironically, the B-2 has some design compromises to allow it to operate at low altitudes for penetrating strikes, as stealth wasn't quite as trusted when it was being designed - and low altitudes allow operating below the horizon from radar installations. (The B-21 renderings look like they've dropped those compromises - high altitude penetration only) I'll agree that using cell phones to detect the presence of stealth aircraft is more than a little dubious, though.