Can someone tell me the function of the radio altimeter in the 737NG? I seem to remember it has something to do with me decision height, as when I used to fly the PMDG 777, I used to set it for me Decision Height (I think)? Also, is there a way to have the 737 automatically call out "MINIMUMS" at the correct (as per published approach plate)decision height (Like I think it does in a real 737)?Thanks.Chris Catalano

Hi,The most important function of the Radio Altimeter is that, unlike the normal altimeter, it gives you the aircraft's height above ground level (AGL).Charlie

you also can set it to "baro" if you push just a bit above the knob itself.The BARO function is in function with the Altimeter settings. So if you set the wrond pressersetting you also get a wrong baro.Thats why RA is safer.

To get the minimums callout, you need to set the callout altitude to what you want the callout at.Use the upper left dial on the MCP (center click sets to 200, clicks on either side adjust up or down, you will see Radio ### at the bottom right of the PFD)To have it go away for takeoff, you should be decrementing this to 0 (the Radio ### will disappear).Ray

TCAS II requires a radio altimeter as well. It is required for setting altitude-specific sensitivities, and most importantly for disabling descend RAs near the ground. You wouldn't want to be 600' AGL and be told "Descend, Descend" to go under traffic.In the NG, all RAs will be inhibited below approximately 1000' radio altitude.Lee Hetherington, PP-ASEL (KBED)

"Thats why RA is safer."Not if you're flying directly towards a cliff face :-) Rad Alt radio beams only look downwards ;-)There are many examples of aircraft crashing into "ordinary" mountains despite having Rad Altimeters.Cheers.Ian.