confused on which altitude offset to use

[Jason Fayre]

Hello,

I'm trying to read the aircraft altitude and am confused which offset to use.

Should I be using the radio altitude (31e4), or the altimeter reading (3324).

There are a few other offsets for altitude as well. Any help would be apreciated.

 

 

[Thomas Richter]

Hi,

it depends on what you are doing with the Offsets. In relation to flying you use Altitude with Baro settings and for i.e. landing you want to read Radio Alt (below 2500 ft).

0x3324 gives the Altitude not Baro corrected and is also depending on user settings Metric or US to show in meter or ft (0x0C18)

0x31E4 gives Radio Alt in m

0x34B0 gives the ambient pressure alt corrected by pressure setting (0x0330), Kollsman

So 0x3324 (m or ft) just reading the Altitude, 0x34B0 to read Altitude but you need to correct with 0x0330 pressure setting and 0x31E4 to read Radio Alt but you have to check the user setting (0x0C18) if it is m or ft.

Thomas