737 RA CALLOUT

[Monkey can fly]

I am a 737NG pilot,during my training ,my instructor told me when the RA callout 50,that means the gear is 50ft above ground,but I doubt it.he told me the RA is calibrated to indicate gear height during flare.Is he wrong or not?Thanks!

[IRRenewal]

You're asking the question on the wrong forum. You might get a better response if you take a bit of time and effort to post in the correct forum.

What reason do you have to doubt your instructor? What do you believe the RA shows and what is that believe based on?

[Chesty Morgan]

Yes that is correct. It's why it reads a negative
value with the nose wheel on the ground.

[Banana Joe]

I'm quite sure this info is also in your manuals...

[Monkey can fly]

Yes that is correct. It's why it reads a negative
value with the nose wheel on the ground.
Thanks.But I recall the FCTM says when cross the threshold,the pilot eye height is around 50ft,and the wheel is around 35ft.So if the RA callout means wheel above ground.how come we hear 50 normally when we cross the threshold?

[PFD]

Hi. The Radar Altimeter will give you the height of the lowest wheels (Mainwheels) from the ground +/- 2 feet at 50 feet. If you have rising ground just before the runway threshold, then it might be possible that the flight deck would be lower than 50 feet as the Wheels pass 50RA, but unlikely this close to touchdown, especially as the RA is an important part of an autoland system. Have a good read of your FCOM.