[Steve Morley]

..plus the transponder mode charlie may be under reading. Mine does (either that or Farnbro' is over reading and I now fly 250' below at least to stop them teling me I have busted CAS.

One of my group routinely flies odd altitudes in congested areas - 2150ft etc on the assumption that most people will be flying 2300 or 2400.

[Guest]

The Maximum permissable mode C transponder error is +/- 200 feet. More than that and you need to go and visit the avionics shop.

If you are showing 200 feet or more into controlled airspace when flying below it, the problem is yours.

[Steve Morley]

I know. Maybe I wasn't clear When I fly at 2400' Farnbro ask me my height and say I am showing just in CAS. Then I tell them and they say it's within tolerances. So I fly 2300'.

really. Do I have to explain everything to you SEP wallahs?

[buzzman]

An ATCO watching you on radar has a duty of care to you, whether they like it or not, and if equipped to prevent you from hitting another aircraft, this will override the limitations of the service that you are being offered, to the extent that this is technically and operationally possible.

Great idea but we weren't offered that then and I have never been offered it since.