OK.....technical statements for the masses 102.
"So mr pilot why have we climbed so high?"
"We have climbed to 10000 feet because the airplane performs better at altitude"
"OK, but the Airspeed indicator is showing 10 kts less than cruise at a lower altitude?"
"That is because the air is thinner"
"but how can a propeller be more efficient through thin air?"
Any suggestions on a succinct simple explanation to explain the above to a lay person over the noise of lycoming IO-540s 2 metres away?
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Those who restrain desire do so because theirs is weak enough to be restrained.
William Blake