The app author is releasing an updated iPhone app soon.
NCYankee wrote:
I use full throttle and max RPM for climb.
That is also what Bob Kromer recommended for the Mooneys. Unfortunately those articles have gone by now but they were quite good.
Basically the profile is Full throttle and max RPM for climb all the way to TOC and then fly WOT and 2500 RPM leaned to best power or best economy. He and others claim that this is the best profile you can fly a non turbo engine. Clearly, CHT must be monitored in certain installations, particularly in Mooneys, if flying with full power and several engines actually have limitations on the use of full take off power to a certain time limit.
I’ve done this twice, on departure from Samedan. The change in performance is noteworthy if you leave max RPM on.
Take off power reduction to 25/2500 often is used in Europe in particular for noise abatement. And clearly, 2500 RPM will reduce the ambient noise vs 2700. So that is why in terrain where max climb is not necessary, we still do it. Apart from that, the POH actually refers to 25/2500 as climb RPM.
What I’ve also seen in this regard is that while MP stays where it is (usually 26-27 in low elevations) only RPM is reduced for noise. By the time this is done, MP usually is close to 25 anyhow.
Basically the profile is Full throttle and max RPM for climb all the way to TOC and then fly WOT and 2500 RPM leaned to best power or best economy
Yes WOT is way to go for climb and cruise altitudes, anything else drags the engine…at low levels setting less throttle is OK in cruise
For RPM, I don’t think 2500rpm from Bob Kromer is the perfect number for cruise? 1/ with CSU propeller stays efficient down to 1950rpm (it may lose 1% theoritical efficiency but low rpm on 3 blades get you a reduction in froction, noise, blade interaction and -0.5gph in fuel burn) 2/ the propeller rpm has to be adjusted higher with altitude if you are after best power (100rop) above 10kft 3/ Mooney POH best economy (max egt to 25rop) is useless if one could operate smoothly in LOP with fuel flow, cht/egt monitors on each cylinder…
In 4 cylinders Mooneys,
For MP & RPM in climb, yes I do hear 25/25 in 4 cylinder Mooneys, I have not figured out where that comes from? poh clearly state wot/max for max climb and 26/26 in normal climb…I am sure the 25/25 relates to noise harmonics or maybe some undocumented CPL Complex training?
There is a fantastic amount of stuff out there about engine management and most of it is very old stuff based on no engine instrumentation and thus no understanding of what is going on.
Ibra wrote:
n 4 cylinders Mooneys, If one is looking to save fuel and cover distance: WOT, 2200rpm, 30lop is the sweet 55% economy in 6kft-8kft band (2200rpm & 28mp < 75% power and one can lean at any altitude) If one is looking to get there fast (as some think it’s the essence of Mooneys): WOT, 2500rpm, 100rop is the sweet 75% power in 6kft-8kft band
Yep.
One should not forget that Mooney always has been about speed, particularly in the US. Hence no wonder that their former top guy recommends going balls to the wall. Mooneys in many regards are looked at as “Ferraris of the skies” and that explains why those of us for whom the main advantage of a Mooney is efficiency get shot down in the community when asking about how to get the most gas mileage e.t.c.
If you follow Mooneyspace you might have noticed I got total lack of any understanding when I wondered aloud about how to operate the 3-blade prop I got as there are no power setting tables available for the regime the RPM restriction imposes. The answer I kept getting is, just get into the damn airplane and fly it and when you get short on fuel land, fuel and carry on. Which, in the US can be done, here the situation is different, you usually can’t do that particularly on a longer cross country and with all the PPR restrictions we have.
The fact that range is the best speed mod has not necessarily a lot of meaning in places where you have a suitable airport with gas every 15 minutes of the way.
