throttle and RPM.

[Kenne]

is the throttle the one i have on my controls that increase MP?
if so, what does the control we use with the + and  - key on the keypad.

[BaldEagl]

Throttle controls manifold pressure and +/- on the keypad controls RPM (blade pitch).

[Kenne]

Throttle controls manifold pressure and +/- on the keypad controls RPM (blade pitch).

so if i use the +- to decrease the rpm, im in fact increasing the pitch of the blades?

in a cruise enviroment, would this be like OD in a car?

[ink]

so if i use the +- to decrease the rpm, im in fact increasing the pitch of the blades?

in a cruise enviroment, would this be like OD in a car?

more like a neutral....decreasing your RPM extends the gas mileage......

[Randy1]

Curious, is it modeled in AH that feathering the prop on a dead engine will decrease drag?

[Wiley]

Yes.

Wiley.

[kvuo75]

Curious, is it modeled in AH that feathering the prop on a dead engine will decrease drag?

yes

singles don't fully feather though

[Kenne]

more like a neutral....decreasing your RPM extends the gas mileage......

i understand that because i can see it in the ECB.

but if the +- decrease RPM it must be by increasing pitch.

so therefore i should reduce to max cruise by using the +- (prop pitch) instead of the throttle.

[ink]

i understand that because i can see it in the ECB.

but if the +- decrease RPM it must be by increasing pitch.

so therefore i should reduce to max cruise by using the +- (prop pitch) instead of the throttle.

yes

[BaldEagl]

i understand that because i can see it in the ECB.

but if the +- decrease RPM it must be by increasing pitch.

so therefore i should reduce to max cruise by using the +- (prop pitch) instead of the throttle.

No.  You should use both.  Max cruise requires reductions in both manifold and rpm.  E6B will give you the approximate settings.

[RTHolmes]

... so therefore i should reduce to max cruise by using the +- (prop pitch) instead of the throttle.

depends entirely on the engine. eg. for spits you should set full throttle and use the prop pitch to set the required boost level*. this method doesnt really work in the jug though where you need to set both pitch and throttle to the cruise settings.

your best bet is to grab a copy of the pilot notes for your favorite ride and do it by the book. this has worked for every aircraft Ive tried it on, which is pretty impressive - wtg HT!


* this is how you can climb to 25k in a spit XIV and still have 50mins cruise at 330mph

[Brakechk]

so if i use the +- to decrease the rpm, im in fact increasing the pitch of the blades?

in a cruise enviroment, would this be like OD in a car?

I always thought of rpm affecting pitch in terms of how hard the prop is digging in.  So less rpm...less pitch....less digging....less load on the engine...less fuel consumption but also less speed.

I'm obviously not a pilot lol

Zaphod

[mthrockmor]

Where do I find the "pilots notes" for the planes? I've never heard of this.

[FLS]

You may find a link to the POH in Wiki or AH Wiki when you look up the aircraft there or you can search the internet for "pilot operating handbook P-51" as an example. You won't find every POH and many sites are not free but you should be able to find most of the US and British aircraft.

[RTHolmes]

Pilot Notes for almost anything the RAF flew are available as cheap reprints on amazon, Operator's Handbooks or Operating Instructions for USN/USAAF birds the same. Axis handbooks not so easy to find, I have a couple for the Luftwaffe but good luck finding Russian or Jap stuff. www.scribd.com has quite a few viewable online otherwise google them, theres lots of PDF scans out there.