long or why are there difficulties to do it here? have there been or are there now any consequences or ramifications with the airlines? reporter: so interesting, we have just seen a tweet from air india which operates some flights into the united states and it says it will have to change certain types of airplanes, that it will have to change certain types of routes because of this. the faa has proposed a notice to airmen in which it says pilots should be especially concerned because of errors in their radar altimeters, possible errors in radar altimeters, that they should be especially attuned to this. i ve seen what has happened in cockpits, what can happen in cockpits at the eaeronautical university. it can throw instrumentation errors, hard to determine what is happening in the airplane if your radar altimeter goes out. we know that american airlines has said it could delay or cancel flights to a magnitude in which it can t really understand