Our class C airspace at KRDU has a 4400 ceiling. If I fly Westbound above the airspace at VFR cruise, I'm expected to be at 4500. Since this is a tiny margin and I don't want to bust into the airspace by accident, do some pilots fudge on the cruise altitude and create a larger margin for themselves, flying at say 4600? I'm a lower hour pilot and while that's no excuse to bust minimums, just asking what you all think. Yes yes, flying at 6500 is also an option but this was a rather short XC scenario, plus let's assume a cloud layer at say around 6000MSL. :-)

  • $\begingroup$ Usually when I fly over a Class-C, I call approach and just let them know I'm overflying. If they respond to you at all (with your callsign), you are cleared to enter, so flying at 4500 isn't a problem. $\endgroup$
    – Ron Beyer
    Commented Nov 14, 2019 at 16:09
  • $\begingroup$ See aviation.stackexchange.com/q/15015/520 regarding Ron Beyer's comment. $\endgroup$ Commented Nov 14, 2019 at 17:19

1 Answer 1


I had a similar situation flying over the Class C at Albuquerque New Mexico. Albuquerque's Class C goes up to 9,400 and I was flying VFR at 9,500. In this case I was using flight following going from Las Cruces NM to Santa Fe NM and was handed off to Albuquerque Approach. Albuquerque Approach simply told me to notify them if I needed to make any altitude changes to remain VFR.

I think most pilots would simply call Approach in this situation and let them know they are flying over their airspace. You would need to know the correct altimeter setting anyway to make sure you are at the right altitude.

  • $\begingroup$ Correct me if I'm wrong, but you could simply get the ATIS to adjust your altimeter to? Still, I like the idea of notifying approach. Also: is there a good standard phraseology for relaying that particular piece of information? I don't mind just saying "FYI I'm flying 4,500 over the Class Charlie" but I'm also working on my ATC a bit more and want to sound more professional. $\endgroup$
    – saigafreak
    Commented Nov 14, 2019 at 21:19
  • $\begingroup$ @saigafreak: If you were not handed off through flight following I would tell approach that you are overflying the airfield at 4 thousand 5 hundred and give your intended route of flight. You could get a close enough altimeter setting through ATIS although the ATIS would not be updated every time the altimeter value changed. Also if you have dropped into the Class C due to turbulence you would not be in trouble since you are in contact with approach. $\endgroup$
    – DLH
    Commented Nov 14, 2019 at 21:39
  • $\begingroup$ @saigafreak I would prefer to hear something like "Approach, N12345, 20 miles to the west requesting transition over the Raleigh Class Charlie at 4500" (and your aircraft type code if you didn't use your type as part of your callsign). That lets them know that 1) you aren't an inbound and 2) you aren't requesting flight following all the way, just a transition through the airspace. We would ALWAYS prefer to be talking to you instead of not, even if you're technically not in the Charlie. $\endgroup$
    – randomhead
    Commented Mar 1, 2021 at 2:56

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