Originally Posted by
43Inches
Yes that is what an encoder does, however a pilot flies via the information displayed on the Altimeter, so if that is in error so will his maintained height. However if the aircraft is flying level this will show as an erroneous altitude being flown to ATC out by the amount the altimeter is in error by. The passing altitudes on first contact on climb will only highlight a gross error say more than 300 ft from what the screen shows and the pilots reports. Considering an Cat 1 minima is 200ft then 300ft the wrong way could put you in the ground. Hence why lower approaches have altimetry check points. Cat 2/3 rely more on radio altimetry so its not as critical.
43Inches. You will see that my post was at time 7.48 - exactly the same time as yours. So we were posting in parallel and I was not disagreeing with the post that you were writing at the time but hadn't appeared. I agree with you. The purpose of my post was to correct the info on transponder altitude information posted by LB at 7.26.
Fly Safe
PJ