Messerschmitt 109 Improvements

[GregP]

Can't see crap out of it except forward or to the side. Forward and left or right is problematic. Lots of sky blocked out or distorted compared with other fighters.

Go sit in one. Bad and easily correctable with very little effort.

 

[stona]

Slats (and fixed slots) keep the air on the top surface from separating (stalling). An Aileron trying to operated in a stalled or partially stalled (disturbed) air-stream looses effectiveness. The slats/slots do not "improve" aileron effectiveness over what it would be at low speed with the wing un-stalled, but they help maintain the effectiveness at high angles of attack right before the stall or even a bit during it. Many wings do not stall all at once but progressively from the wing root out or from the tip in. The slats/slots keep the area of the wing they affect (pretty much the area behind them) from stalling, at least up to a point. The root/ mid wing area may be stalled and the plane loosing lift and mushing but if the outer wings are NOT stalled the ailerons allow some lateral control.

Yes, the slats prevent the wing from stalling, the fact that the ailerons still work is due to the unstalled condition of the wing. Keeping the wing flying at high angles of attack is the function of the slats, continued aileron effectiveness is a function of the unstalled wing, not the slats. It's a bit pedantic but its a chain of functions, one dependent on another. The designers did not install slats to keep the ailerons working, they installed them to stop the wing stalling, and the aircraft from stopping flying.
The Spitfire wing stalled from the inboard area outwards which meant it could still fly, with aileron control, even when partially stalled. Experienced pilots could make the famously tight turns in this condition. Lesser mortals would not. It didn't need slats to do this, but it was a much more sophisticated shape.
Cheers
Steve

 

[stona]

Can't see crap out of it except forward or to the side.

You certainly can't, the view is appallingly bad. It's also not exactly the most aerodynamically slick piece of armour.

Designing a new canopy with better vision ultimately falls back on the Bf 109's biggest shortcoming. It was just too small.

Cheers

Steve

 

[cimmex]

Can't see crap out of it except forward or to the side. Forward and left or right is problematic. Lots of sky blocked out or distorted compared with other fighters.

Go sit in one. Bad and easily correctable with very little effort.

After the war Avia designed a new hood for their S99/199 series but kept the windshield, Spain also used the old design even Switzerland as a foreign customer didn't request a new one and there was no pressure of war. I would like to see your proposal without altering the slim fuselage and still have an armored screen in front.
cimmex

 

[Tante Ju]

The Spitfire wing stalled from the inboard area outwards which meant it could still fly, with aileron control, even when partially stalled.Experienced pilots could make the famously tight turns in this condition. Lesser mortals would not.

Yes, its doable with a washout, even though that washout was fairly commonplace so I do not see why to invoke another baseless spitfire fetish outburst in a 109 advancement thread... its silly, especially given that the Spit was half a generation behind in aerodynamic solutions - virtually all high lift devices were absent from it. Yes you can provide huge chunk of wing which may give you still enough lift when the roots stall, the 'only' downside is that you are 30-40 mph slower that way.

Designing a new canopy with better vision ultimately falls back on the Bf 109's biggest shortcoming. It was just too small.

The canopy may have been better designed though I do not see how and compared to what. The idea was to semi-sink windshield (and the pilot) into the fuselage, as in case of the Fw 190 and P-51 for example (the "German school" of some North American designers is notable). This limits 11-2 o clock vision of course, its a price you pay for more speed. A Fw 190 style canopy and windshield could be adopted without much ado, I am not sure why it wasn't (one probability is the requirement for pressurized cocpit on G series which is a huge factor for high altitude pilot efficiency). The oft and erroneously claimed "size issue" was certainly not among the reasons.

 

[stona]

Yes, its doable with a washout, even though that washout was fairly commonplace so I do not see why to invoke another baseless spitfire fetish outburst in a 109 advancement thread... its silly, especially given that the Spit was half a generation behind in aerodynamic solutions - virtually all high lift devices were absent from it.

It's not silly and I resent the implication.
If you bother to read the post to which I was replying to you will see that it was not I who raised the issue of progressive stalling along a wing. My response was entirely relevant to that post. I used the Spitfire as an example, there are plenty of others. The Bf 109s use of slats was one solution to a problem, but there were others that did not use your "high lift devices". Leading edge slats were hardly cutting edge in the mid 1930s! They can be a fix for a wing which misbehaves at low speed or high angles of attack (or both), as seen on the Me 210/410.

Cheers

Steve

 

[stona]

A Fw 190 style canopy and windshield could be adopted without much ado, I am not sure why it wasn't

Because the Bf 109 has a very slim fuselage and you would need to make a "low back" version like later versions of P-47s, P-51s, Spitfires and others. I don't believe that could be done "without much ado" and I'm guessing that the designers didn't either.

Cheers

Steve

 

[Shortround6]

Yes, the slats prevent the wing from stalling, the fact that the ailerons still work is due to the unstalled condition of the wing. Keeping the wing flying at high angles of attack is the function of the slats, continued aileron effectiveness is a function of the unstalled wing, not the slats. It's a bit pedantic but its a chain of functions, one dependent on another. The designers did not install slats to keep the ailerons working, they installed them to stop the wing stalling, and the aircraft from stopping flying.

A bit pedantic to be sure, many aircraft had the spats/slots pretty much in line with ailerons and not over the majority of the wing or the entire wing. Planes like the Fiesler Storch, the Westland Lysander had full length slats. Even the Swordfish had slats but only on the upper wing in front of the ailerons (no ailerons on the lower wing). Lockheed used fixed slots on the Electra airliners and Hudson bombers, again just in the aileron area (of course they used wacking big Fowler flaps just inboard of the ailerons for lift).
You are correct on the chain of function but if they were truly looking for more lift to keep flying the slats/slots would have covered a greater area of the wing like the STOL aircraft. The slats kept the outer wing from stalling, not the inner, just like the Spitfire's washout.

 

[razor1uk]

Most aircraft I think, if they do have washout (measured at the tip), it's usually between -0.5 and less than -5 degrees; 5 degrees downwards/negative (hence the '-',) perhaps ignoring the wing designs angle of incidence.

On jets, the higher speeds, to me, less washout might generally be needed so as to not restrict higher speeds or controllability (unless they want it more unstable - look at the tips(-/tiprails) of a F-18C the F-18G) via aerodynamic induced and parasitic drag caused by the washout; all that is also dependant upon the wings shapes, its various loadings and the aircrafts envisaged usual flight profile etc.

 

[spicmart]

Designing a new canopy with better vision ultimately falls back on the Bf 109's biggest shortcoming. It was just too small.

Yak-3?

 

[stona]

FYI the Spitfire's inflight loaded wing has a washout of +2 degrees at the root and -0.5 degrees at the tip, thus creating a twist axis of 2.5 degrees along the wing.

Since this is a Bf 109 thread I will elaborate no further, except to say that for this, and a variety of other aerodynamic reasons, this wing did not require the addition of drag inducing lift devices to enable it to fly safely at low speeds and high angles of attack.

Cheers

Steve

 

[stona]

Yak-3?

I know nothing about Soviet aircraft I'm afraid! I'm guessing that it was designed from the get go with the bubble canopy and flat back and not modified as such?
Cheers
Steve

 

[Milosh]

How wide was the 109's, the Spitfire's and the P-51's fuselage at the cockpit?

 

[Tante Ju]

I know nothing about Soviet aircraft I'm afraid! I'm guessing that it was designed from the get go with the bubble canopy and flat back and not modified as such?

Cheers
Steve

Yak 1, the immediate predecessor of Yak 3...

Lagg 3, the immediate predecessor of ...

.... La 5/7 series.

Also looking on the Spitfire, which is at least as slim in the fuselage, and could successfully adopt a bubble canopy with a "cut" fuselage, I do not see why it cannot be done in the 109. A lot of aircraft successfully done (P-51, P-47, Yak, La series etc.), for some reason Mtt did not want. IMHO it was certainly doable. Perhaps they were satisfied with the rear view after the installation of the Erla cockpit, or there were other reasons like pressurization, which was in effect until 1944 with variants... the last version, the K was largely redesigned in 1943, when this was a concern. It is very difficult to obtain proper pressure maintain with a canopy with neccessary gaps for sliding action.

 

[spicmart]

How wide was the 109's, the Spitfire's and the P-51's fuselage at the cockpit?

The Yak-3 seems to have a wider cockpit section than the 109 even if the Yak being even a smaller airframe though.
Yet it seems it had not the vices that plagued the 109 design.

 

[Milosh]

Didn't the PR Spitfire have a pressure cockpit? Iirc so did the Ta152H.

 

[stona]

Not sure what the point of those Soviet aircraft is. If you build a Yak 3 with a bubble type canopy, then it's not a Yak 1. I have never suggested that a version of the Bf 109 could not be made with a better canopy. I simply said that the idea that it would be a simple thing to do is not supported by the evidence. There may well have been "much ado."
Who knows what structural changes were required between the two Soviet aeroplanes? There may also be problems of longitudinal stability (as on the P-51). This wasn't one of the Bf 109's, or Spitfire's, strongest points to start with.
A lot depends on how the fuselage is constructed. On a Spitfire it was relatively simple to alter frames 11 to 18 and the relevant skins. The Bf 109 fuselage which is effectively built in two halves might not be so easy. Each halves skin plates are made in one piece with alternate plates formed with Z-section flanges which constitute the frames or formers to which plain intermediate plates are riveted. It is a very production sympathetic method of construction, but not so easily modified.
Cheers
Steve

 

[razor1uk]

Once the design of those fuz halfed sections was finalised and distributed to the 'shadow workshops'/fabricatiors amongst the wider population, getting all of them to swap the old former for the new one once the new changes bugs have been worked out would have been more difficult than writing it suggests - include that to the loss of production and or wastage of meterials during the change-over, and you can envisage why they kept to the design, assuming it wasn't all just Willy's fastidiousness to science and his demon, the risk to losses in production.

That's not to say they perhaps with hindsight could not have done something equivalent earlier or better etc - like the Erla Canopy(../ies) Galland Glass, but just producing and changing to those two designs is at least 1/8 easier and quicker than altering the rear cockpit, storage/pilots locker, the rear fuz sections the fuz halfs, the possible airflow effects affecting the tailplane fin + rudder behaviours that'd need 'checking rechecking prior to calibrating', and then the likely conversion training of pilots should it handle too differently.

 

[stona]

As a matter of interest some of todays Spitfire war birds are low backs converted to high backs. This is done by adding "quarter frames" on to the frames I mentioned, above the top (datum) longeron. Again, relatively simple.

This is actually a Seafire 47, but it will serve.

There's absolutely no way a similar modification could be made to a Bf 109 fuselage without effectively re-making a good proportion of it, if not everything behind the cockpit.

Cheers
Steve

 

[Tante Ju]

There's absolutely no way a similar modification could be made to a Bf 109 fuselage without effectively re-making a good proportion of it, if not everything behind the cockpit.

I still struggle to see why, perhaps you can explain and highlight the major differences in construction? To me the fuselage construction of the Me 109 and the Spitfire are quite similar. I do not see how the joining method for the two plates effects this - in the 109 the sections slided into each other, giving a smoother transition - but the shape was decided by the ribs and the longerons provided stiffness on both planes.