Kurt Tank did it first

[Krusty]

Jaws, I stand by my statement. While there were some that had fixed pitch props (glaidators, for one, early hurricanes, and some others), I'd say that 90% or more had a variable pitch prop (most had constant speed props, some had variable pitch, but nearly all had some form of prop pitch control).

[HoHun]

Hi Krusty,

>While there were some that had fixed pitch props (glaidators, for one, early hurricanes, and some others), I'd say that 90% or more had a variable pitch prop (most had constant speed props, some had variable pitch, but nearly all had some form of prop pitch control).

Roger that. A fixed propeller wasted a lot of performance, so a variable pitch propeller (usually with a constant speed control) was a must for fighters in WW2.

With regard to single-lever controls (from http://www.hitechcreations.com/forums/showthread.php?s=&threadid=171089):

One comparative US report report on the FW190 expresses doubt on whether the command device would allow to get the best performance and economy from the engine. On the other hand, there is a detailed NACA report showing that it handled non-linear relationships of some half dozen parameters, and I believe it would be hard for a human operator to manage the engine with similar effectiveness.

However, after WW2 additional sensors were installed in piston-engined aircraft that provided the flight engineers with more data than available before (stuff like brake mean effective power gauges and exhaust temperature thermometers), and from what I've read, that really took engine management a step beyond what was possible during WW2, command device or not.

The command device, by the way, was not unique. The Jumo 213 for example had a "single lever control device" that was even more advanced than its BMW counterpart, regulating charge mass instead of boost pressure to get higher power below full throttle height.

The Allies, too, had single lever control devices. The French had employed one for the Dewoitine D. 520 even before the war, but apparently it still had some issues, judging by Eric Brown's test flight impressions. The late-war Spitfires had an "interconnected control levers" operation mode, too, which apparently worked just like a command device, at least when the engine was operating at maximum power. For normal climb and cruise situations, the pilot could override this system for better efficiency.

Regards,

Henning (HoHun)

[Bruno]

109's from F onward had single lever operation, I believe. Later Spitfires had an "auto" position for the prop lever(fully back), which if engaged allowed the throttle lever to also control rpm's.

Emils were retrofitted IIRC in late '40 or early '41 (before Barbarossa) and in FB/AEP/PF this is modeled for the E-series (E-4, E-4/B, E-7) etc...

I have read where FW pilots would sometimes run into problems maintaining formation due to the lack of fine tuning of power.

Justin is corrct in the the FW had a manual override of the kommandogerat for emergencies, meaning that if something went wrong with the function of the kommandogerat the pilot could switch to manual and be able to land the plane. IIRC the 'manual' setting didn't allow full control over prop pitch but it was a single pitch setting.

On Butch's AAW2 Forum forum member 'schwarze-man' made a detailed post describing the 109s system.

Some of the points he stated:

In manual the pitch of the blades is set by use of the two-way rocker
switch on the throttle (marked "kleiner/grosser"(U/min)) and by reference to the propellor pitch indicator "clock". In automatic mode the governor adjusts
the propellor pitch to give the U/min required by the throttle position.

Because the automatic control is not effective below 2000U/min , it would keep trying to drive the prop to finer pitch and could burn-out the electric motor, automatic is only selected just before take-off. In automatic the throttle position controls the engine speed and manifold pressure in accordance to the designed engine performance table.

So, how does this all look in the cockpit?
First,we must decide on the use of manual propellor or automatic propellor.
In manual propellor control (selected on the switch below the throttle-box
marked"HAND--AUTOMATIK" to "HAND") the pilot can select the prop to run
faster or slower ("GROSSER--KLEINER") by using the rocker switch on the
throttle.

I won't quote him any firther but his posts goes on to give many details.

As I understand it the single lever control on the DBs was far less complicated then the 'kommandogerat' system used on the BMWs...

[Wrangled]

Alot of these arguements can be resolved by making sure both sides read the same reference materials. The only way to resolve this type of discussion is to have somebody that actually flew the aircraft in WWII.




It is a game, no more no less.

[Glasses]

That's how it worked

[gripen]

The single lever system in the Fw 190 seem to be the first succesfull system of it's kind but generally all advanced engine controll systems used during war were invented long before WWII (like CO analyzers, density metering systems, variable ignition advance etc.). Practical utilization just took time.

gripen

[Crusher]

Here is a good article on this subject.
Constant speed is the norm in WWII. It is a special kind of variable pitch.
After reading, you should get a much better idea of why we don't need a control for prop pitch.
Props

[Debonair]

i would like to use this as an opporutity to bring up another old tread on FW 190s started by me, who pwns n00bs
http://hitechcreations.com/forums/showthread.php?s=&threadid=171089
still wondering about it....

[Crusher]

Personal experiance:
Running in over rich condition probably fouled sparkplugs and killed engine performance. However, in an overheat situation, it would cool the engine if left on for a minute or so. I definitely think that the over rich setting might have been used to cool the engine but it was not left on for extended periods.

 14.7:1 is considered the ideal mixture setting. Rich limit would be about 12:1 and lean limit  is about 16:1. Over rich would then use something akin to 10:1 and would, therefore, waste a lot of fuel as well as foul or even flood the engine.

Butwhaddoiknow!

[Debonair]

Originally posted by Crusher
Personal experiance:
Running in over rich condition probably fouled sparkplugs and killed engine performance. However, in an overheat situation, it would cool the engine if left on for a minute or so. I definitely think that the over rich setting might have been used to cool the engine but it was not left on for extended periods.

 14.7:1 is considered the ideal mixture setting. Rich limit would be about 12:1 and lean limit  is about 16:1. Over rich would then use something akin to 10:1 and would, therefore, waste a lot of fuel as well as foul or even flood the engine.

Butwhaddoiknow!

i think this is where i read stuff, its in my bookmarks for some reason
http://naca.larc.nasa.gov/reports/1945/naca-wr-e-192/

accordong to this when using Kommandogerat, the BMW was rich mix if RPM was over 2150.
my guess is that this was part of the solution to the early 190A's overheating problem & i would assume that in a desperate situation, one could go to manual mixture control, find peak & by getting the power boost, pwn some n00bs, but i've never read if anyone did this.  Even if you weren't desperate, why not extend your range a bit?
odd thing i read about, the mixture was toggled lean to rich at 2150 RPM, so pushing the power lever forward from 2140 RPM to 2160 RPM would give a bit of a power loss

...another odd thing is that even a brand new Cessna 172 doesn't have single lever power control, but somehow my 11 year old ford has it operated by my foot, rofl

what is your personal experience?