View Full Version : What is the allowable margin of error for a DME arc?
RTN11
22nd Sep 2014, 20:04
What is the allowable margin of error for a DME arc?
I thought it was +/- 0.5nm, but people I've been flying with lately (who are more senior than me) think it's +/- 1.0nm, and we're all struggling to find a reference.
Cough
22nd Sep 2014, 20:41
CAA standards doc for IR's (http://www.caa.co.uk/docs/33/SARG_Standards%20Doc%201%20v8%2022%20July%202014.pdf)
Check appendix 3
B737900er
22nd Sep 2014, 20:44
Depends is your following TERPS or Pans-ops.
In the UK, the CAA guidance document for candidates for the initial instrument rating test states +- 1nm for DME arcs.
OhNoCB
22nd Sep 2014, 21:10
1nm for IRT anyway as said above. Have heard this was simply due to some DME's only doing whole miles, but I have never seen one myself so don't know.
FWIW I think 1nm is a massive tolerance, I am no hotshot by any means but either I have a knack for DME arcs or it's a generous allowance, because I used to be disappointed to not keep it within +-0.1 when doing my IR.
Centaurus
25th Sep 2014, 11:49
In Australia the DME arc tolerance is plus or minus 2 DME and has been ever since the first DME was installed in this country. It is a common sense figure thank goodness.