I agree with both Level Attitude, and Flybymike.
What level were you planning to fly?
If you must fly so close to the edge of the CTA, fly at 1400' on the Stansted QNH, then if you drift towards CAS you will be just below it.
Also, don't forget about the TMZ below the CTA.
In any case, at least use the Listening Squawk, and listen out with Stansted, but why not pre-empt the situation by calling them in good time, and saying that, as your track
may go just inside the CTA, you are requesting a crossing clearance.
MJ
