No Hoper (and others) please correct me if I am wrong, but say you set the static timing carefully to 20 degrees before TDC.
When the engine is running at around 2500 RPM, the actual timing will be around 12 degrees BTC?
Yes – ‘ish’, on bog standard piston aero engines. The static timing depends on the specific engine model – some 22, some 24 for
example. The amount of delay between the points physically opening at e.g. 22 and 24 BTDC and the spark happening is in the order of half a dozen to a dozen degrees, depending
mainly on engine RPM.
The kind of timing referred to by No Hoper – using a strobe light – has its own built in delays. To put this another way around, the strobe does not flash the instant the points physically open. Often the strobe flash is triggered by the spark itself by a sensor on the spark lead, and the timing mark has been marked based on that assumption.
But I’ve had an awful revelation. I’ve just looked at the POH for one of the aircraft I usually fly, and have realised there is
no procedure for descent! That is, it doesn’t say lower the nose or pull the power or anything else about
how to get from cruise altitude to terra firma. What will I do?
