You do not think that thought has occurred to the satellite people by now and has been checked?
A number of governments know exactly what happened. They don’t want to let on what their surveillance capabilities are.
The bad guys did this as a dry run for a future multiple simultaneous hijackings. They need to know everything that needs to be shut down to avoid detection.
Well... unless they release a list of all the places they checked (even if we limit it to known airports), then I have no way to know or not know if they did.
The question is, are you absolutely sure they did think of it? Remember, they were searching the wrong ocean to begin with.