The 109... questions

[adonys]

actually I remember that they had even less than 10, that being only 5 minutes of full power combat time above London.

it was the main reason Luftwaffe haven't completely obliterated britain fighters during BoB because someone decided to start it before having the fuel tank ready for the 109s (and the fact that all pilots bailing out were recovered and flying again the next day for britons, while was lost as PoW for germans).

[Al Schlageter]

Originally Posted by JG52Uther

When I get the time I will take off from France and fly to London at cruise settings,to see how much fuel is left.
I think in real life they had 10 minutes or so combat time over London,so it must have been pretty hair raising trying to get back while avoiding enemy fighters. I already flew one mission out in the channel,got a fuel leak and only just made it back to base with empty tanks and the fuel light on! That was bad enough,and no one was shooting at me!

Some data for the E-1/E-3

SL
Max continuous: 2200rpm, 254mph - 1.05hr, 267mi
Max economy: 1300rpm, 164mph - 2.02hr, 404mi

16,494 ft
Max continuous: 2400rpm, 323mph - 0.55hr, 286mi
Max economy: 1300rpm, 217mph - 1.50hr, 413mi

[II./JG1_Krupinski]

Originally Posted by Geronimo989

Ok a quite simple and maybe stupid question: Does more RPM always mean more power on the 109, with the risk of breaking the engine when exceeding the limit? Or do you get maximum power when staying in certain RPM range (2500) and you actually LOSE power when you exceeding it?

Absolutely not... However, power is dependent upon RPM. That is power is a "rate" of work being done.

Use the Prop Pitch control to regulate the engine load by maintaining a certain RPM. At a high pitch, it's harder for the engine to swing it than at a lower pitch.

All internal combustion engines produce power on what's called a power curve, named because the relationship between torque output and RPM is not linear - it's a curve. Hard to describe but imagine an engine running at idle may produce an increasing amount of torque at an increase of RPM (with a constant load) up to a peak.

Then any additional RPM beyond that peak will start reducing the torque output, even though RPM's are increasing. (Side Note: In internal combustion engines, the power and torque numbers are equal at 5252 RPM)

A dynamometer, is used to measure the power parameters of an engine. The dynamometer operator will increase the throttle from idle to max throttle and measure the RPM and torque output.

Using a variable pitch prop [bf109] or fixed pitch prop [tiger moth], the propeller can represent the constant load (assuming you don't change the variable pitch) exerted on the engine, and taking the throttle from idle to max throttle will exercise the engine across it's power curve.

If the propeller is a constant speed propeller (spit) then the propeller will adjust its pitch (adjust its load) automatically to maintain a certain load. Since the engine produces power on a power curve, you can stick the RPM to the peak level and then worry about one less thing. As you increase throttle, the engine RPM will increase until there is enough power to swing that prop at the given setting. A constant speed prop makes it easy to keep the engine at the best RPM for a given situation, such as MAX performance, or MAX economy.

A variable pitch propeller the pilot must adjust the propeller pitch to do the same thing, as an increase in throttle will increase the RPM of the engine, unless the pilot increases the load on the engine.

A fixed pitch prop, the pilot must adjust the RPM's with the throttle.

Usually, aircraft manuals aren't published with detailed power curves, but what they do have is settings for varying scenarios. The CoD manuals have some values published, but I've seen more detailed tables in other game manuals (such as the shockwave A2A Bf109 manual - which you can view online)

Here is a nice web page that discusses power and torque.

http://www.epi-eng.com/piston_engine...and_torque.htm