Originally Posted by
bjr_93tz
For me, because just about every comp was far away and at sea level, so I always have that little nagging voice asking me "is the mixture going to be ok?" for the first flight.
I think dragging an electric out of mothballs and putting a battery in for round one on Saturday morning is a bit less worrying than trying to get a few passes in with the YS just to make sure it's ok..
My main flying field is around 1000ft and the other one I fly at regularly is at around 500ft. Going from one to the other of these doesn't require a mixture change, but the plane does fly a little different at the lower altitude.
In April, I went to Hawkes Bay, New Zealand, which is at sea level to compete in the Trans Tasman. The engine was a bit lean there, so I richened the reg 1/8th of a turn and the needle 5 or 6 clicks. 500ft shouldn't need retuning, but more than that, depending how big the altitude change is, then richening the reg 1/8th and up to 1/4 a turn on the needle should be pretty close.