I have been reading the AOM regarding proper use of the APR and I am not quite sure I have this figured out. Looks like it is used during icing conditions on takeoff and automatically feathers a failed engine as well as providing a power increase. I am wondering if this is the case why it is not used on all takeoff's and landings.Mark.

Maybe I've been doing it wrong but I turn it on for all takeoff and approaches (in case of go around). I figure if it is going to help me in a single engine event then I want it.

Mark,APR use isn't limited only to takeoffs in icing conditions. Though that is one of the few times it's actually required to be used.It is used frequently for non-icing takeoffs when required by runway length or required climb gradient. In these conditions, though, it's often optional...you could simply take a weight penalty instead. But these penalties can be rather hefty, and since airlines are in the business of making money, bumping 4 or 5 people off the airplane isn't usually a viable alternative.When conditions allow, APR should be off and a reduced torque takeoff should be made. But when it's hot, you're on a 5,500ft runway, and there's mountains off the departure end, APR is the way to go.APR can also affect your maximum landing weight in circumstances where you're approach climb limited, do APR is often on for the approach too. If APR is inoperative, you can take weight penalties both on takeoff and landing, depending on the runway and conditions. As is often the case with detailed addons, it's hard to operate with full realism without the performance data that is normally consulted before every takeoff. Like the 747 or MD-11, the J41 has runway specific charts that spell out the max takeoff weight and takeoff torque setting.Regards,Nick

APR switch is turned on for take-off and landing (check relevant items in AFTER START and DESCENT/APPOARCH checklist).APR is operationally armed once RPM is greater than 99% (note white labels LAPR ARM, RAPR ARM lit on CAP).APR becomes active if an engine fails and torque on other engine is greater than 65% (green APR/ORVDE label on button below APR switch) . APR will feather the failed engine and boost torque (no more than 100%) and EGT of the operating engine. Also the EGT limit on the "good" side will increase by 40 C. APR is cancelled : if lit APR override button is pressed, if APR switch is turned off, if torque on good engine is less than 65% (a bit difficult this one...)Useless trivia : each hour of APR operation reduces service life by 300 hours and 12 cycles. Note : APR is tested prior to take off by pressing the APR override button below the switch. You will observe Torque/EGT/fuelflow rise and then press the override/test again to cancel.Hope this little info is short enough to digest.Vangelis

Thanks, great info.Mark.