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Fe2b Throttle/mixture graphic

Posted By: gallen13

Fe2b Throttle/mixture graphic - 11/08/22 05:37 PM


In the FE2B, what I assume is the throttle lever shown in the cockpit is actually controlled by the mixture adjustment, is this a bug?
Someone posted a very informative list of aircraft/control list by aircraft type.
For the FE2B it says use the throttle, do not use the mixture adjustment.
Posted By: Bletchley

Re: Fe2b Throttle/mixture graphic - 11/12/22 10:52 PM

Hi gallen13

Yes, it looks as if the graphic movement of the throttle lever in the cockpit is controlled by the mixture adjustment controls, although functionally everything appears to work as it should (just a graphic anomaly).

I think the list you are referring to is the one by Old Hat, based on something that I wrote. The FE2b with the 120 hp and then 160 hp Beardmore engine, based on the Austro-Daimler, did not originally have an altitude compensating carburettor (no mixture control). The low service ceiling (11,000 ft) is indicative of this. At some point the 160hp Beardmore would have been retro-fitted with an altitude compensating carburettor (probably from late 1917) and by the end of the war it was a standard fitting. The later FE2d with the Rolls Royce engine would have had one as standard (service ceiling 17,500 ft).

For an FE2b without mixture control I would suggest that you set the mixture control in Workshop to Automatic.

I hope that helps smile

B.
Posted By: Polovski

Re: Fe2b Throttle/mixture graphic - 11/13/22 07:15 PM

Edit:

I had a look, and I believe it is correct. Several images and videos show the controls as such. One crashed image shows "Advance and Retard" signs next to the side control indicating it is a mixture lever.

In the FE2b in WOFF the throttle is on the control stick (look down, easier with TrackIR). I have seen this in several images and videos such as those with Gene DeMarco flying.

If you have information to the contrary, then I'm all ears.

I have also seen images with two levers on the opposite side (throttle/mixture it looks like) but maybe another variant.

Posted By: Bletchley

Re: Fe2b Throttle/mixture graphic - 11/14/22 10:56 AM

Hi Polovski,

Yes, you could be right - if it was a late version of the Beardmore engine it would have had a mixture control lever smile

But Advance/Retard sounds like the spark (magneto) advance/retard to me - this was commonly found as a lever on the left hand side of the cockpit in German engine cockpit controls (and the Beardmore started out as an Austro-Daimler) where the throttle lever is on the control stick. The FE2b might have been different, but in most British and French controls I think the mixture control was usually next to the throttle on the throttle quadrant (and, interestingly, French movements were back to front, ie. move backwards to increase, forwards to decrease, if you want to model that correctly on French aircraft!).

Quick look on the internet and I found this picture of a spark advance/lever - not an aircraft one, but I think much the same! https://www.themagnetoguys.co.uk/advance-and-retard.

This is description of starting the 160 hp Beardmore from the Vintage Aviator, although I couldn't see a picture of the spark Advance/Retard lever mentioned:

The engine is relatively easy to start, in fact sometimes it starts itself ! After your engineer climbs up onto the wing root and carefully balances there while priming each of the six brass primer cups from a squirt can of raw fuel, he needs to clamber back to ground level and pull the engine through a few blades before the prime evaporates away. A call for “all switches off” signals the engineer that it is relatively safe to rotate the four bladed prop. Then, a call of “ready” from the engineer signals the pilot to make his last checks of all the cockpit controls and to ensure everything is in the proper position; fuel selector “Main tank to carb,” air selector “Hand Pump”, air pressure at 2.5 PSI, check service tank is full by looking at the glass sight gauge built into the side of the tank, position the spark advance to “retard” and now to try a start... Pilot calls “Clear” and selects “2” on the mag switch which allows the engine to run on both magnetos, then select “On” on the booster magneto switch, all this time the engineer is trapped in a maze of bracing wires and struts trying to remain clear of the soon to be rotating knives called a prop. If we are lucky the engine will come to life with just a spin of the booster mag, otherwise the engineer has to earn his keep and actually hand swing this very big, very awkward engine. Once started, maintain air pressure with the hand pump and keep the revs to below 800 RPM until the water temp reaches 60 Celsius. Move the spark advance lever to “Advance” and check for an increased smoothness in the engines’ beat. Before setting off it is a good idea to have your engineer look over the engine while it is running, as this aircraft is a pusher, there is no way of detecting oil, water or fuel leaks.

B.
Posted By: Polovski

Re: Fe2b Throttle/mixture graphic - 11/18/22 12:33 PM

Ah ok thanks Bletchley. I think it was the later Beardmore I was modelling I'd have to check though, or I guess I could make the lever to work in a similar manner to a spark lever.
Posted By: Bletchley

Re: Fe2b Throttle/mixture graphic - 11/18/22 05:58 PM

I had a look at the details provided for the WOFF FE2b, and it is the early version with the 120 hp Beardmore engine (9,000 ft service ceiling). I did a bit of digging around, and the 120 hp Beardmore was essentially an Austro-Daimler 6, but with Beardmore carburettors, so I think you are right about the throttle being on the flight stick. This would be typical for an Austrian or German engine of the period, as would a spark advance lever to the left hand side of the cockpit. But the twin Beardmore carburettors of the 120 hp version were definitely not altitude compensating, so would have had no mixture control lever, and I think the large lever on the left hand side of the cockpit is therefore most likely to be the spark advance. In these engines the spark advance lever was there to help start the engine, in the retard position, until the engine had warmed up and the lever could be advanced to give smoother running and best power. It could play a small role in compensating for altitude, as advancing the lever further, at higher altitude, could help to compensate for lower density air by giving slightly longer for the oxygen-poor mixture to fully ignite, but the effect was marginal and only used in that way, to my knowledge, in the Hispano-Suiza. Later versions of the FE2b had the 160 hp Beardmore, a slightly enlarged version of the 120 hp, but even those would have started out with non-compensating carburettors (11,000 ft service ceiling) through to the autumn of 1917 when it was switched to a night bombing role. Later output of these 160 hp engines would have had twin Zenith altitude compensating carburettors, but it is difficult to say when they were introduced as it would have been a relatively simple matter to change the carburettors (once they were available) and add the extra control line through to the cockpit for the mixture lever. But I would guess not until late 1917 or 1918. This would have increased the service ceiling to around 17,000 ft, but as the FE2b was by then primarily a night bomber this would have been largely unnecessary and may not have been fitted unless it came as standard with the engine. The performance figures that I have seen for the FE2b with 160 hp Beardmore have the lower 11,000 service ceiling, indicating that they had a non-compensating carburettor as standard for most of the war. The FE2d, introduced in 1916 and used through to the end of 1917, had the Rolls Royce Eagle engine which was fitted with a compensating carburettor from 1917 (17500 service ceiling). The Vintage Aviator's FE2b is powered by the later 160 hp Beardmore (probably a post-war build, as Beardmore continued to produce them into the early 1920s), which has twin Zenith carburettors with (as the manual says) 'altitude control fitted', but I doubt this would have been typical for a 1916-17 FE2b used in the escort fighter or day fighter-bomber role.
Posted By: gallen13

Re: Fe2b Throttle/mixture graphic - 11/19/22 11:24 PM

WOW...thanks guys. It did not interfere with my fun, just curious.
Posted By: Bletchley

Re: Fe2b Throttle/mixture graphic - 11/20/22 09:26 AM

Yes, gallen13, it does nothing to detract from the excellent simulation of the FE2b in WOFF. Just set mixture to Automatic in the Workshop settings.

When Polovski pointed out that the throttle was on the flight stick, that piqued my interest as well. I will have to start an FE2b career now smile

Some time ago I did some digging around in the area of WWI aero engine carburettors, but never really looked at the Beardmore engine so I was curious, thought it was worth following up.

If you are interested in following your curiosity further there are some posts at The Aerodrome forum on WWI areo-engine altitude controls (so far as I know, no one else has every really looked in detail at this):

http://www.theaerodrome.com/forum/showthread.php?t=31874

https://www.theaerodrome.com/forum/showthread.php?t=31875

http://www.theaerodrome.com/forum/s...light=altitude+compensating+carburettors

Also here, for some discussion on the use of spark advance:

http://www.theaerodrome.com/forum/s...light=altitude+compensating+carburettors

And if you really want to disappear down the rabbit hole, a post on WWI experiments with a stratified charge to effect altitude control:

http://www.theaerodrome.com/forum/showthread.php?t=43716&highlight=ricardo

B.
Posted By: gallen13

Re: Fe2b Throttle/mixture graphic - 11/20/22 12:41 PM

Fascinating stuff, thanks for the links and info. Excellent reading for the dark winter nights.
Interestingly, while I was preparing my carb for a ULEZ test on a Harley sportster which has a Keihen CV (constant velocity) carb, someone mentioned that it did a good job of adjusting for height variations! Possible of some importance in the USA.

Alas my FE2b pilot, due to a control failure (my joystick) cracked up on landing and is no more. I have rotated to a German pilot and this has led to a somewhat related query:

Is the photo recon mission height given in the instructions for above sea level or terrain level. Because flying photo recon in the Alsace region all pictures taken were too low, suggesting that height above terrain level is required. This makes sense. At a guess I would need another 700m over the stated 3000m and I wonder how the Aviatik B1 will cope. Did they just push it to the limits ? I will try .The Aviatik B1 in oldhats list says no mixture control but it does seem to be modelled in plane.

Please don't feel obliged to spend time answering if you better things to do.
Posted By: Becker01

Re: Fe2b Throttle/mixture graphic - 11/20/22 02:12 PM

Hallo @gallen13,

for photo recon mission you need AGL-display (button "z").


Greetings
Posted By: Bletchley

Re: Fe2b Throttle/mixture graphic - 11/20/22 02:42 PM

Hi gallen13,

As Becker01 says, use "z" to find your altitude - but it zigs and zags about as you cross the mountain ridges making it really challenging to find the correct height. Not usually a problem on the other maps.

Historically, non of those early German planes had mixture control, although every plane in WOFF can use it - I find it best to set mixture to Automatic in the Workshop settings for any plane that does not have altitude control, as this will give you more or less the correct performance at all heights. The list that you referred to in your first post should give you an idea of which ones these are. Others, like the ones with the gnome monosoupape engine (e.g. DH2) have mixture control but no throttle. and I fly these with the throttle setting stuck on maximum, varying engine speed only with the mixture control and blip switch (try it with the DH2, it is fun!).

B.
Posted By: gallen13

Re: Fe2b Throttle/mixture graphic - 11/20/22 03:04 PM

Thanks guys...just completed a photo recon with 1 good plate, 800 m above mission guide height. I am slowly learning.
Posted By: Polovski

Re: Fe2b Throttle/mixture graphic - 11/24/22 04:06 PM

Thanks for the extra digging Bletchley.
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