Nick,
A significantly inaccurate airspeed indicator should be fixed or replaced, IMHO. That's a key instrument. Do a good test with the procedure I mentioned earlier this afternoon: http://edburkhead.com/Ercoupe/airspeed_indicator_errors.htm When you go up next, get medium high and determine the minimum flying speed according to the ASI that's in the plane. Do your first final approach at or a smidgeon above 1.4 times that number on a runway long enough that there's no penalty for landing long. I flare and level out just a foot to a yard or so above the runway and hold it there and hold it there and . . . till it finally touches. The sink in ground effect is low enough that you should always touch down nicely. As you get mastery of that, you can do testing at final approach speeds a bit lower. Be very, very aware that, if you are too slow, a Coupe will develop a really strong sink rate. If needed, apply power. (As the Stromberg carburetor has no accelerator pump, I always counted one-thousand-one, one-thousand-two, one-thousand-three, one-thousand-four from idle to full power to be sure there would never be an engine stumble. (Other people only count to three. YMMV)) Ed
