G'day Aussie Pilot,
You will find as many different opinions on the correct power settings to use as there are flying schools or engineers on the field. We own an Arrow II and the most popular teaching is that after takeoff and gear and flaps (if used) are retracted then 25" and 2500RPM are used for the climb. Then regardless of the required performance or altitude 23" and 2400RPM is stated as the power setting to use. This is to ensure that the so called "golden rule" of MAP not exceeding RPM is maintained. However, as you have pointed out, a closer look at the aircraft flight manual will reveal that this is not always the case. I don't have the Arrow II table here but from memory 75% pwr @ 2,000ft calls for 25" and 2400RPM.
Whilst the Mooney is a much more slippery aeroplane you can still apply good handling of the engine in the Arrow by planning the descent and reducing MAP by say 1" per thousand ft or every two minutes. Even greater reductions are not really going cause instantaneous cracking of cylinders (unless you close the trottle at 9,500 and descend at 150kts.) but in the interest of engine care, try and be as conservative as possible.
Listen to your instructors, talk to engineers and other experienced pilots and get their views on how they best handle the power settings.
Good luck with it.
[ 07 January 2002: Message edited by: Islander Jock ]</p>