B737 NG EGPWS test
Evening Ladies and Gents
Just wandering if anyone can shed a little problem. If you select test from the EGPWS control panel with the IRSs both off, no terrain video is shown on the displays. If the IRSs are turned on during a test, after about ten seconds the video appears. If they are on before the test is selected, the video is there from the start. It is as if the EGPWS requires some validity flag from the IRSs. Any avionics aces out their know if this is the case?
Would appreciate your help as I don't have enough documentation here to prove one way or the other.