TCAS Altitude incorrect.

[Kirkus]

TCAS altitude shows -24 for both aircraft despite being at the same level. The pilot off the CPA813 messaged me to tell me that my level on their TCAS was being displayed as -24. and I was also displaying them as -24.

Both planes were at 37000.

 

 

Edited March 2 by Kirkus

[RogerWilco]

Same issue. I am on 410, aircraft in front of me 390... TCAS says -36