Throttle and propeller RPM!

Is there any auto propeller pitch in the spitfire MK IX like the BF-109K or it will be like the P-51D, separate throttle and propeller pitch!

I've found a video with a LF MK XVI With an auto prop and an override lever. But it's not ''exactly'' the same engine : The Merlin 266 was the Merlin 66 and was built under licence in the USA (wikipedia Mk XVI (type 361) !!! :helpsmilie:

And why the h... the P-51D lack this kind of features?

Like P-51, i.e. separated throttle and RPM which has to be moved and set in proper sequence to avoid engine damage. I wonder if that, underrev and the like are part of the engine model.

So, no automated controls, albeit allegedly, a limited number of later Spits supposed to had a sort of primitive imitation of it, where the throttle and rpm could be moved forward together by a simple mechanical device.

Really? Interesting...

I'd somehow got the idea that the merlin 66's onwards had the interconnected throttle and prop controls, as described in paragraph 20 of the pilots notes:

http://www.zenoswarbirdvideos.com/Images/spit/SPIT9MANUAL.pdf

I'd somehow got the idea that the merlin 66's onwards had the interconnected throttle and prop controls, as described in paragraph 20 of the pilots notes:

S!

Anyone got any more info on it? Like the AP or the plans? Devs?

I'm certainly very interested in finding out more. (For the record, I prefer the idea of flying a "manual" prop anyway.)

It's the same engine basically as a mustang, so it has the same basic control set up. most supercharged aircraft engines had a mechanical interlock that was basically a little metal flap that you could flip down and either locked the throttle and prop control together, or blocked the prop control from moving ahead of the throttle, causing over-boost and possible engine damage. the exact setup differed between manufactures and aircraft, and country of origin.

the German automated set-up was a great advantage in combat as it freed up the pilot load so he could concentrate on flying instead of engine management

the German automated set-up was a great advantage in combat as it freed up the pilot load so he could concentrate on flying instead of engine management

An "automated" set-up probably meant very little in the real world, because properly trained pilots would have had no problem controlling both throttle and propeller, even during combat. Once muscle memory is established, such things can be done automatically, without putting any conscious thought into the process.

That's why helicopter pilots can fly helicopters and modern fighter pilots can use HOTAS to control so many different functions during combat.

An "automated" set-up probably meant very little in the real world, because properly trained pilots would have had no problem controlling both throttle and propeller, even during combat. Once muscle memory is established, such things can be done automatically, without putting any conscious thought into the process.

 

That's why helicopter pilots can fly helicopters and modern fighter pilots can use HOTAS to control so many different functions during combat.

I think you should take into consideration the historical circumstances.

The fact is, that at this time, Germany did not have many properly trained pilots, only a small group of "veteranen" and then a lot of young ill trained novices with too little stick time.

For such a group it made sense to ease the workload of these young pilots, so they could be somewhat functional in battle.

I think you should take into consideration the historical circumstances.

 

The fact is, that at this time, Germany did not have many properly trained pilots, only a small group of "veteranen" and then a lot of young ill trained novices with too little stick time.

 

For such a group it made sense to ease the workload of these young pilots, so they could be somewhat functional in battle.

That didn't turn out to be the case, yes it eased work load however the German pilots come 1944 were rushed through with little flight training, this was a failure in the luftwaffe to address losses and use the experienced pilots as trainers I believe Adolf Galland expressed remorse at his lack of judgment in this regards.

The RAF in comparison constantly cycled the veterans either to training or to fighter command allowing there knowledge to be passed on.

The Americans were trained to a high standard before they were sent overseas

An "automated" set-up probably meant very little in the real world, because properly trained pilots would have had no problem controlling both throttle and propeller, even during combat. Once muscle memory is established, such things can be done automatically, without putting any conscious thought into the process.

 

That's why helicopter pilots can fly helicopters and modern fighter pilots can use HOTAS to control so many different functions during combat.

From pilot accounts everyone liked the automatics much, both LW pilots and allied pilots who tested captured planes. "Very little" or not, it was less workload for pilot during combat anyway...

Could we keep this related to the Spitfire, please? :)

Okay, I'm throwing down the gauntlet here: can those of you who support a physical linkage at the throttle quadrant kindly provide evidence that this was the case in the mk IX Spitfire? (Andy, Alan... I'm looking at you...)

I'll admit it certainly seems like the simplest and most logical explanation. However, I have been through my copies of the flight manuals, period plans, contemporary photos, and Monforton's rather excellent book... and I can find no evidence that the throttle lever was physically connected in any way with the airscrew control.

If people are interested I can post the relevant pics, but take my word for it: the airscrew lever is entirely inboard of the plating on the throttle quadrant, this plating does not have an opening that might allow for a connecting lever, the throttle lever itself is only pierced for mounting the L-plate that flips the master switch, and the airscrew control connects directly by Teleflex to the airscrew mechanism.

I have seen two type of metal object external to the throttle quadrant plating that interface with the airscrew control: the first is a simple spring plate that retains the airscrew control in its aft-most position (and seem to be for earlier - fully manual - aircraft, as it seems to be removed by "mod spit.1026" in 43/44), while the second is a brass plate with a solid stop to prevent the airscrew being moved aft of the vertical (which seems to be for the later - automatic - aircraft, and can assumed to be the above modification). Neither of them penetrate the plating or interact with the throttle lever.

Anyone got any info on the Rotol airscrew end of things? That might help...

My understanding of PN description is that in the modified planes the prop lever itself served as auto-manual selector, with aft detent added for "auto" (RPM-MAP interconnection) operation and anything forward of it overriding mechanism for standard manual operation. But that's just my interpretation of it.

My understanding of PN description is that in the modified planes the prop lever itself served as auto-manual selector, with aft detent added for "auto" (RPM-MAP interconnection) operation and anything forward of it overriding mechanism for standard manual operation. But that's just my interpretation of it.

Likewise. That's been my reading of the info. Fully-aft for auto, but with a manual override if you advance the lever any.

From the pilots notes for the IX

The point there is the "If Fitted" in 39 (v)

The point there is the "If Fitted" in 39 (v)

S!

Anyway, it's still a mechanical "device", impossible to model since it won't move the controls magically for you at the moment you use a couple axis for throttle and pitch. IMO it has no point whatsoever. Anyway, let's see ED rendition of the feature on the 16th of December.

 

 

S!

Hmmmm. I think we may have been talking at cross-purposes here: I don't think anyone has implied that the (Spitfire) airscrew control wiggles about whilst set to "automatic". My reading of the PNs was that the lever in the cockpit is either set to auto (where it remains) or one can advance the lever as a manual override. The quasi-magical moving bit of it is all at the other end of the control cable, at the airscrew.

As you say though, this is all base speculation... I too look forward to seeing how ED has chosen to implement it. :)

(PS - Some of the 737 lads build "magic" self-moving throttles and trim-wheels, don't they?)

Well, you make me doubt now if we talk about the same feature :lol:.

(PS - Some of the 737 lads build "magic" self-moving throttles and trim-wheels, don't they?)

S!

Even though the propeller lever is different than the throttle it's not totally manual. The propeller lever sets the RPM and automatically changes the pitch to keep you at that RPM. It's really not that different than the Bf 109. Just put your throttle up, set RPM to whatever you want (on the Merlin anywhere from 2600-2800 is usually good for all situations) and fly. Don't see what's more difficult on this method than the Bf 109. At least it's not like the early 109s where you had to manually control the PITCH and were always adjusting whenever you changed speed, in a climb, dive, etc.

Even though the propeller lever is different than the throttle it's not totally manual. The propeller lever sets the RPM and automatically changes the pitch to keep you at that RPM. It's really not that different than the Bf 109. Just put your throttle up, set RPM to whatever you want (on the Merlin anywhere from 2600-2800 is usually good for all situations) and fly. Don't see what's more difficult on this method than the Bf 109. At least it's not like the early 109s where you had to manually control the PITCH and were always adjusting whenever you changed speed, in a climb, dive, etc.

What he said...

Had a thought whilst in the bath: what if the term "auto" is a red-herring? A constant-speed prop is already "auto" to all intents and purposes - set the desired rpm and forget (see linky below); and the spitfire had a constant speed prop from August 1940. NB: this is not the same as the variable pitch prop some of you are referring to - the constant speed will cope with over/under-speeding

So what changed? I was looking at the PNs for the mk IX and started comparing the advice for flying economically for auto/manual props (section 3, paragraph 55). The number of 2650 rpm pops up consistently, which is coincidently the max continuous rpm of the engine at cruising (+7) boost.

Okay, here's the wild theory: what if nothing changed? Or rather, what if the odd brass stop I described (as evident in later "auto" models), that prevents the airscrew controller from going further aft that the vertical, is just that - a stop... that prevents the rpm being reduced below 2650 (an rpm the Merlin seems comfortable burbling along at indefinitely, or at least until the fuel runs out).

Not so much an "automatic", as a "you really don't need to pull it further back than this and confuse things, Mr Combat Pilot". Whilst still allowing one to push it forward to engage a higher RPM if required.

How can we test this theory? See if the "manual" spitfire maxes out at that rpm with the lever in the same position. Anyone got one handy?:music_whistling:

http://www.boldmethod.com/learn-to-fly/aircraft-systems/how-a-constant-speed-prop-works/

Apologies for double-posting, but I found this whilst flicking through one of my period manuals (AP 1732b). You'll note that it implies that the "throttle" lever on the Spitfire actually set the desired level of Boost, rather than directly working the throttle itself.

So, it seems our Spitfire had (at least) two automatic features, both downstream of the pilot's control levers: a constant speed prop and an automatic boost control. Neither of which, I'd like to point out, would cause the pilot's control levers to wiggle about in sympathy with their changes. Not sure where that idea came from...

From my understanding, 'boost' (manifold pressure) and throttle (fuel introduction) are always automatically adjusted in conjunction with each other through the throttle lever. Nothing else would make sense.

Read paragraphs 19 and 20 in the manual Cripple posted.

Really? Interesting...

 

I'd somehow got the idea that the merlin 66's onwards had the interconnected throttle and prop controls, as described in paragraph 20 of the pilots notes:

http://www.zenoswarbirdvideos.com/Images/spit/SPIT9MANUAL.pdf

From the pilots notes for the IX

 

 

The point there is the "If Fitted" in 39 (v)

Thank Alicatt; take off part V! It is exactly what i was looking for.

But now, i'm stuck with another question.... ''If'' means it can be fit or not?

Yo-Yo, Wags, anyone,... video please! :smilewink:

The Pilot Notes description mention a "override lever" and "stop", and not suggest that throttle lever move the propeller pitch lever (in similar way to Hurricane in what the throttle lever move back the mixture lever).

What this description suggest is that propeller pitch lever in the quadrant is no more "propeller pitch" control like in previous Spit, but a override for the propeller pitch control linked to the throttle (mentions "interconnection device", a clutch???).

Say that if override lever is ahead the "stop", the throttle control for PP is canceled and the lever can increase RPM up to 3000.

The pictures included show a stop in quadrant, but these are from from Mk. XIV. Similar in Mk.IX?

 

Originally Posted by Ala13_ManOWar View Post

Anyway, it's still a mechanical "device", impossible to model since it won't move the controls magically for you at the moment you use a couple axis for throttle and pitch.

In game a key/button for simulate this "override/stop"?

Override/stop OFF: throttle control PP.

Override/stop ON: propeller pitch control became effective (by axis, keys, buttons/HAT).

Boost is regulated by means of throttle, ...

You mean by the throttle lever, the thing the pilot holds in his hand.

... regardless of manual or automatic logic. ...

Why do you guys insist on making me work :cry:

... Fuel is metered by carburettor that knows nothing about throttle lever position. There is only one exception - Jumo 213, where throttle lever controls fuel and air mass flow is maintained automatically regarding this scheduled fuel.

Well yes, okay, I see that now; if only it were as simply as you state it :noexpression:

Rolls-Royce Merlin Automatic Boost Regulator

Now I've forgotten what the point is I was trying to make :helpsmilie: