D-OCHO
What an earth is this nonsense????
but also leaned by an test pilot
Of course it was leaned by a test pilot when it was being tested for certification!!
This irreponsible posting could give young pilots the impression that leaning is some kind of 'msytic art' beyond PPLs, when in fact it is a straight forward operation that can be learned in a few minutes from a good instructor.
If you lean the engine per the instructions and then plan sensible fuel reserves, the risk of being caught out by fuel starvation is much reduced.
Also, if operating from high altitude airports, it is necessary to develop full power for take off.