I know it is common courtesy not to cut in front of anyone, but trying to enter a circuit which has 2 or 3 plane already circulating, you need to cut in front of one plane and position behind another. Then everyone needs to adjust their circuits as there is now one more plane circulating.
If you fly a six minute circuit, with three planes, then the spacing should be 2 minutes each. By adding one plane you either all need to be doing 8 minute circuits, or accept a 6/4 = one and a half minute spacing.
At the airfield at which I fly, it has been known for pilots to opt for an impromptu local flight, instead of joining in the already packed circuit traffic.
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