B737NG radio altitude landing callout
Hi all,
I got a question about the B737NG radio altitude callout when landing.
when the aircraft calls 50 40 30 20 10, and when it reaches 0, the lading gear touchs down.
But I know this altitude is not the distance from main landing gear to the ground, it`s the distance from the RA antenna to the ground.
I heard there is a program pin calibration in there between the RA and landing gear altitude. But I don`t quite know about it.
Can anybody tell me about this program pin? And from what altitude this calculation start?
Thanks a lot!