ORIGINAL: KidEpoxy
...Pylon Timing doesnt work in 15mph wind, when a Tigermoth can have negative groundspeed in foward flight.
Then, without the 15 mph headwind, the Tigermoth can't go any faster than 15 mph. Problem solved.
Seriously, one just needs to measure the time between pylons going both directions, then average the two to remove the effects of wind.