And since we're on this Prop/MP related thread, I would like to take advantage of the fact that the FLIGHT team is closely monitoring this forum to ask again, desperately :-) for a fix to the prop/reciprocating model in FLIGHT.

 

None of the three C/S prop models in FLIGHT (I can't speak for those without a cockpit because I am unable to monitor the RPM / MP there...) works correctly in as far as the RPM <--> Manifold Pressure relation is modelled.

 

Varying the RPM should have a noticeable impact on the MP - Increasing RPM reduces MP and lowering RPM increases MP.

 

Please fix this MS FLIGHT team ;-) preferably on the next DLC.

 

For me this is the kind of stuff (you may well not understand why...) that acts like a Go/No Go decision regarding the support/use I give to a flight simulation platform!...

 

I'm picky, you may say... Yes I am :-)

I haven't jumped to 'Flight', yet.. but these topics have always caught my attention.. especially if we're talking fixes, and that Microsoft is listening.

 

Along the lines of fixing the MP as RPMs change (with a set throttle, a change in RPM must alter the MP slightly).. I'm curious about the fuel-flow(FF) in Flight.... In previous versions.. FF was unrealistically tied to 'power' (or vice-versa).. IOW, you could set optimal mixture by peaking FF.

 

Scenario: Climb to 5000msl without leaning.. level off and begin leaning... FF would actually INcrease at first.. peak at optimal mixture, and THEN begin falling off. I just accepted that that was how we were 'punished' - less power for for non-optimal mixture. The FF gauge actually behaved more like a EGT gauge.. I'd even change the background bitmap, and install it AS a EGT gauge, in some models.

 

Does this 'bug' exist in Flight, too?

Does this 'bug' exist in Flight, too?

 

Yes, it's still there :-(... That's why I fear not having the Prop/MP fixed... speaking of which, depending on the engine/prop/etc... it is not allways that slightly that MP varies with prop ... ;-)

 

Nice to see you around here - been a loong time since I last read a post from you ;-)

There are variable pitch and constant speed propellers.

 

With variable pitch propellers the propeller lever directly controls blade angle. With constant speed propellers the propeller lever determines rpm and the constant speed mechanism changes the pitch angle as necessary to maintain the rpm.

 

Early Hurricanes and Spitfires had fixed pitch propellers. These were superseded by variable pitch propellers with only two settings - "fine" and "coarse". In turn these were superseded by variable pitch propellers.

Yes, it's still there :-(... That's why I fear not having the Prop/MP fixed... speaking of which, depending on the engine/prop/etc... it is not allways that slightly that MP varies with prop ... ;-)

 

Nice to see you around here - been a loong time since I last read a post from you ;-)

 

Thanks .. :) .. and yeah "slight" is relative. A normally aspirated engine's MP is function of available atmospheric pressure, throttle opening, and the rate at which the pistons are "evacuating" air from the manifold. At a set throttle, and constant atmospheric pressure.. higher RPMs = more 'vacuum', hence lower MP.

 

mgh, poins out and important distinction, though the terminology is always an issue. I was taught that a CS-prop, a controllable-pitch-prop, and a ground-adjustable-prop, are all "variable pitch props", as opposed to a fixed-pitch-prop.

 

As for CS-props.. this thread is pretty accurate, but the discussion still wanders off into the arena where people think of blade-pitch, and that the prop-control adjusts blade-pitch... ie. prop-control full forward equals fine pitch. Just keep in mind, that from takeoff roll, to climb, to cruise, to descent.. the physical blade-pitch can go from "coarest to finest", and back again, without ever touching the prop-control.

 

The best analogy I've heard (and have posted many times), is to visualize prop-blades as wings, so that their "airspeed" is RPMs, and the CS mechanism is the "pilot".

 

-Actual pilot constantly adjusts wing AoA during a climb, to maintain Vy

-CS mechanism constantly adjusts blade AoA to maintain a set RPM (the prop-blade's version of Vy)