[fulltlt]

"I would agree it could make identification difficult ... but it wouldn’t make your radar signature disappear. your blip would still exist"

Incorrect. If you fly low enough you can avoid radar. Hence the term, flying under the radar.

[sten]

true, but there would be the ‘descending below radar’ stage between that and normal cruising altitude

that would have appeared on radar as well... not just gone.

the early speculation of a missile was dismissed as falling debris would have been seen on radar as a descending cloud of reflective materials... and there was nothing descending

[jim_trent]

"Incorrect. If you fly low enough you can avoid radar. Hence the term, flying under the radar.

Something not mentioned so far is that IF the airplane was flown at low altitude, the range would be decreased substantially. Jets are not very efficient at low altitude. That would change the search area quite a bit.