At 15:31 23 May 2020, Dave Springford wrote:
Hi Tim,

Sorry, I paraphrased too briefly, but the net effect of the code is that
FES typically doesn't meet the noise threshold and that MOP is therefore
necessary, per your last statement.

As Eric asked above, will ENL "hear" an FES that is running at low enough
power to double your L/D or reduce your sink rate in a thermal?

Anecdotal evidence suggests that it can not and some electric engine
gliders have been seen assisting themselves with power that is not being
recorded in an IGC file by ENL.

However, thanks to @kinsell for reading the OLC rules we now know why OLC
is rejecting FES claims without MOP.

I very much suspect that the ENL values with a FES are dependent on where
the recorder is mounted. If it is close to the engine then ENL may be
satisfactory, but if it is panel-mounted then maybe not so.

Good news for the two LX companies however as I believe they are the only
manufacturers of MOP boxes.