B17 - Engine Drag? Bug? Discuss

[Flipperk]

Ok so I was doing my bombing raids last night and on the way back I shut my engines off and press Alt + X and I start to do a nice decent. Well i noticed when I started my engines my b17 increased its descent rate by -1000 ft/min.

Here is the stats...engines shut OFF... descent rate is -1,100 Ft/Min

Engines on, but idle...descent rate is -2,100.


Seems to me that when the engines are on, even idle, some thrust is created and the descent rate should decrease. Plus with engines off there should be more drag due to non moving props...

This seems backwards....thoughts? 

[GNucks]

Prop feathering.

There have been threads discussing glide distances and what-not, I'll see if I can find them.

[Beefcake]

Ok so I was doing my bombing raids last night and on the way back I shut my engines off and press Alt + X and I start to do a nice decent. Well i noticed when I started my engines my b17 increased its descent rate by -1000 ft/min.

Here is the stats...engines shut OFF... descent rate is -1,100 Ft/Min

Engines on, but idle...descent rate is -2,100.


Seems to me that when the engines are on, even idle, some thrust is created and the descent rate should decrease. Plus with engines off there should be more drag due to non moving props...

This seems backwards....thoughts? 

Let me make sure I understand correctly. Are you saying with the engines off you're getting less drag than with them running? If so then that's correct.

The props on bombers auto-feather so they create as little drag as possible when not running. However, an engine at idle isn't producing any real thrust and the prop spinning is creating a lot of drag so an idle engine will slow the plane down a lot more than one that's off/feathered.

[Flipperk]

Let me make sure I understand correctly. Are you saying with the engines off you're getting less drag than with them running? If so then that's correct.

The props on bombers auto-feather so they create as little drag as possible when not running. However, an engine at idle isn't producing any real thrust and the prop spinning is creating a lot of drag so an idle engine will slow the plane down a lot more than one that's off/feathered.

Ok that makes sense, forgot about prop feathering lo 

[GNucks]

http://bbs.hitechcreations.com/smf/index.php/topic,308063.0.html

I think this is the thread I was thinking about.

[Beefcake]

A little bit more info. Since you were in a dive and the props were off the plane settled on a 1,100 FPM dive. When you started your engines and left them at idle it created a lot more drag so the auto pilot had the compensate by diving the plane more to equal your auto speed setting. This is why your dive increased to 2,100 FPM from 1,100 FPM.

Hope that makes sense.

[AHLongri]

Best way to stretch a glide is--and I bet ALL the pilots,CFI CFII are gonna hit me on "stretching comment"==I was taught by an ooold time FAA check pilot to set you speed about halfway between "best glide" and "stall dierty"--he said it was an old sail plane trick--gives more time in the air than best glide.

[MachFly]

See this thread: http://bbs.hitechcreations.com/smf/index.php/topic,313078.0.html

[smoe]

I would like to know if the engines auto-feather on multi-engine plane or not? I've always assumed yes because I couldn't get confirmation from the rpm gauge/prop levers if they were feathered or not. I messed around with a p-38 and it seemed to auto-feather just from flying performance.

[kvuo75]

I would like to know if the engines auto-feather on multi-engine plane or not? I've always assumed yes because I couldn't get confirmation from the rpm gauge/prop levers if they were feathered or not. I messed around with a p-38 and it seemed to auto-feather just from flying performance.

yes they do.

the prop is stopped, aint it?

[icepac]

Does the typhoon and the a6m3 feather?

They are both pretty rocklike in thier glide performance.

[Beefcake]

IIRC, all single engine planes props will windwill when the engine is off, all multi-engine planes with feather.

[Babalonian]

And a dead engine due to damage (for sure in single-engine craft) is not the same thing in the game as an engine that has been switched off and is windmilling.  It will retain whatever pitch you had your prop set at when the engine dies and the prop comes to a halt (a little trick is to immediately reduce your RPM as much as you can in the time between hearing your engine die and the prop stops spinning, otherwise you're stuck with what you had it set at for the remaining distance that you may or may not try to glide through).

I am not certain if this is also true for dead engines on multi-engine craft in the game, I have been under the assumption for a while that they auto-feather either dead or manually switched off.