Tail surfaces - 109F versus 109E?
 

Hi;

Different sources have claimed that the size of the vertical fin and/or rudder of the Messerschmitt 109 changed from the Emil to the Friedrich model. Was this the case? The most visible difference was the deletion of support struts of course, but various sources also claim a difference in size and also the location of the horizontal plane - but not all sources claim this, and some site only a different in fin or rudder area, so both.

I will say I've had a terrible time trying to locate accurate drawings of these parts. Every other book seems to have drawings, but no two match, and more importantly, I can't get them to line up with photos of the "real thing" either. If I had a Friedrich in the shed out back I could just go out and measure, but unfortunately Friedrich's are fairly few and far between......

Paul

Paul

Re: Tail surfaces - 109F versus 109E?
 

According to 8.109-32 109F Seitenleitwerk drawing rudder of 109F from vertical axis to it's right point should have been 595 mm long vs 653 of 109E on 8.109-20 109E seitenleitwerk drawing while vertical dimension still remains the same 1404 mm. Shape looks like different also.

fin distance was 940.3 mm on F vs 898 mm on E.

But the distanse from rumpfachse (fuselage axis) to the line of stabiliser remains also the same 690 mm

Also 109E rudder had 3 mounting points vs 2 on F/G/K models

Re: Tail surfaces - 109F versus 109E?
 

Very interesting. Thank you for that. Still trying to get the shape right, but this at least gives me overall dimensioning, which is incredibly helpful.

Re: Tail surfaces - 109F versus 109E?
 

Well, if you are after shapes, here are two. The first is from the development and characteristics of the Me 109F by Mtt in Jan 41; and the second is from "Aerodynamic features of the Me.109F2 and comparison with ME.109E" by the RAF, undated. I would tend to favour the RAF one since they would normally work harder to get things right than would the builder.

Re: Tail surfaces - 109F versus 109E?
 

Wow! Thanks for this! Yeah, I find builders drawings, especially German, to be a lot less than accurate.

Paul

Re: Tail surfaces - 109F versus 109E?
 

Sent You examples of factory dwg lists mentioned above.

Re: Tail surfaces - 109F versus 109E?
 

I find this rather surprising. I've no specific knowledge of the German industry, but it is the manufacturer's drawings that go to make the jigs and tools to produce the part: if the part doesn't match it is rejected, for wouldn't do the job for which it was designed.

I can see two possible explanations.

One is that you are not referring to the maufacturing drawings, but to what in the UK are described as General Arrangement drawings (GAs). These are often based on early project assumptions, and only show the basic configuration. They act as the reference centre, from which other drawings show the major assemblies, and so on down (up?) the design tree to the smallest bracket. The drawings of these parts are indeed accurate.

I can confirm that GAs from British aircraft companies did not always reflect later changes made to the design. That's not what they were for.

The other is that the drawings belong to some earlier idea of what the part should be like, different from that finally accepted for production. I'm sure it is very difficult to determine the detailed history of the design of major aircraft parts, and to place every detailed drawing in its proper place.

Re: Tail surfaces - 109F versus 109E?
 

Quote:

I find this rather surprising. I've no specific knowledge of the German industry, but it is the manufacturer's drawings that go to make the jigs and tools to produce the part: if the part doesn't match it is rejected, for wouldn't do the job for which it was designed.

That is absolutely correct. The manufacturer’s plans being off translate to substantial increases in labor and capitol expenditure for the company. While they did not practice six sigma, they most certainly were concerned with profit and quality control. Time and labor must be spent fitting parts as well those parts greatly altering the aerodynamic characteristics of the design.

It does not make sense for a company to do this and remain profitable. Even in the Soviet system, gross deviation from design plans was a major cause for concern.

All the best,

Crumpp

Re: Tail surfaces - 109F versus 109E?
 

Paul asked for a comparison of the rudders of the 109E and 109F, and this I tried to supply. Neither of these drawings was a dimensioned effort and each was created to simply give an idea of shape changes. And, in both reports I referenced, that is all that was intended.

Re: Tail surfaces - 109F versus 109E?
 

That makes sense, George.

Re: Tail surfaces - 109F versus 109E?
 

George was absolutely correct, but if You want to obtain full information on rudder - here you are. I hope I'm not violating any rules of our forum but if so I accept any penalty.

Re: Tail surfaces - 109F versus 109E?
 

Hello,
I am quite sure that the outlines of the E and F vertical tails were essentially the same. However - besides other considerable constructive changes - the rudder axis was moved aft by 39 or 40 mm on the F. This is shown by George Hopp's above Mtt. drawing (which yields 39 mm). The RAF drawing compares only the rudders and thus may falsely suggest that also the outlines of the two tails were different.
On other drawings the horizontal distance of the elevator axis and the rudder axis is given as 85 mm for the E and 125 mm for the F. This would yield an an aft movement of the rudder axis of 40mm, on the assumption that the tailplane did not only keep its vertical position but also its horizontal one.
Last remark: Once you know about the different positions of the rudder axis the different optical impressions of the ratio between the length of the fin and the length of the rudder on photos become striking.
Regards,
klemchen

Re: Tail surfaces - 109F versus 109E?
 

Let's be clear here. Aircraft manufacturers use precise plans and jigs when building their aircraft. We still do the same when building our aircraft today.

All the best,

Crumpp

Re: Tail surfaces - 109F versus 109E?
 

My query was on Pstrany's post, rather than George's, for he specifically wrote "builders drawings". Whether Messerschmitt or German manufacturers in general, he shall have to tell us (and every English grammar teacher will be crowing "Apostrophes do matter!")

(Little joke - I don't really expect all contributors to have perfect English.)

George is almost certainly wrong, in one sense, because it will not have been the RAF but the RAE (Royal Aircraft Establishment) who took so much effort to measure and compare the shapes. At least, it will have been done at their instigation, whoever took the measurements. I assumed George meant simply "the British".

Re: Tail surfaces - 109F versus 109E?
 

Despite Murphy's book the problem is that shapes were really different as it can be seen from Mtt' bauplans.

Look at athe attached files in my above post.

Well occasionally I also have rudder manufacturing and assembling blueprints not only general arrangement dwg I have posted earlier on 109E and some remnants of 109F/G rudder drawing.

They ARE different.

1. Rudder has different mounting points location. F/G/K rudder has 2 points
2. Rudder has different square and shape
3. Fin shapes are different also.

Re: Tail surfaces - 109F versus 109E?
 

Quote:

They ARE different. 1. Rudder has different mounting points location. F/G/K rudder has 2 points 2. Rudder has different square and shape 3. Fin shapes are different also.

I don't think anyone is disputing the fact that the different design variants of the BF-109E/F/G/K experienced design changes. That is silly to dispute.

I am and I believe Graham is also speaking about deviation and distribution of manufacturing errors. Using multiple blueprints of varying measurement for the same type is beyond stupid from both a business and an engineering viewpoint.

When they hit the assembly line floor and the jigs are built, they are NOT different.

Do not confuse the wealth of pre-production and even post production information with that used on the assembly line. The Luftwaffe aircraft are probably the most prolific in their design changes without a re-designation of the type. The FW190 for example had three different aileron hinges with at least 5 different structural designs for the aileron itself. If you understand the affect of hinge point changes then you understand the significance on the stability and control of the design.

The documents you have certainly fulfilled the task and conveyed the information the author wished whether that information was precise or relative. That does not mean that had anything to do with assembly of the jigs or the actual aircraft rolling off the production line.


All the best,

Crumpp

Re: Tail surfaces - 109F versus 109E?
 

Hello,
mmoustaf's drawings are real interesting. They confirm that the rudder axis for the F was moved aft by 39 mm: Its distance longitudinally from the main wing spar (i.e. from the bridge going through the fuselage to which the wing spars were attached) is given as 5262 mm for the E and 5301 mm for the F. According to the drawings, the elevator axis was in exactly the same place for both models, despite different construction of the tailplanes (two pieces for E, one piece for F).
I am not maintaining that the outlines of the vertical tail for the E and the F were the same. The difference of the fins was very slight, but the E rudder was longer than it should be according to my theory. However, there is a discrepancy between George Hopp's Mtt. drawing and mmoustaf's E drawing, also by Mtt.. On the former, the outlines for E and F are the same, and the length of the rudder is specified as 634 mm,
i.e. 19 mm less than on the latter and precisely 39 mm more than the 595 mm of the F rudder.
George Hopp's drawing was made by the flight characteristics department on January 27 in 1941, that of mmoustaf on September 13 in 1942, probably by the same department ("Fleig" stands certainly for Flugeigenschaften = flight characteristics). At that time no E was built any more, so the drawing cannot have been used as a basis for construction. But what was it for then? And how reliable are drawings by Mtt. anyway?
Regards,
klemchen

Re: Tail surfaces - 109F versus 109E?
 

Quote:

And how reliable are drawings by Mtt. anyway?

Like most firms the reports are most likely extremely reliable for the purposes intended by the reports author. The discrepancy comes when one tries to take that information out of context and apply it to something never intended.

The key is having the entire report as well as the context of its development. Good example of that is our engine restoration has dictated we marry both physical and documentary evidence to build a case for the FAA that our engine will be safe to run using the latest manufacturer’s recommendations available.

Quote:

But what was it for then?

Without the entire report we would only be venturing a guess. However several distinct possibilities exist including the investigation of a q-limit raise in the design, the reduction or elimination of Dutch roll, or a decrease in the directional stability stick force per G. These are by no means the only explanation possible.

All possibilities will start out on the slide rule with supporting documents illustrating the design changes.

All the best,

Crumpp

Re: Tail surfaces - 109F versus 109E?
 

For such case we can continue duscussion with two type of drawings and one sample:

- first is Mtt jigs and theoretical outlines for production e.g. plans used to prepare splines and templates. These drawings represent a part of complete set used to restore 109E now and dated 1939. Also some remnants of 109F/G plans are available - that set was used to restore 109G-6 in Moscow;

- second is a drawing from NII VVS report contains dimensions and outlines of a real production 109E obtained in 1939/40 by USSR. So we can see how different are jigs/outlines both discussed earlier from a real sample;

- third is real rudder of 109G and 109E which I could measure. It could take about two weeks because of my skydiving activities

So what way do we choose?

Re: Tail surfaces - 109F versus 109E?
 

We can also draw on our experience as well as three other Warbird restoration organizations representing the majority of the US Market for restoring both Allied and Luftwaffe aircraft.

Can you post those drawings?

Thank you!

Re: Tail surfaces - 109F versus 109E?
 

Which do we do ? All of them, of course.

There does seem to be an unexpressed absolute lurking in this thread: that there was only one standard of fin/rudder for the E, and only one other for the F. Therefore manufacturing plans that do not match existing examples must be wrong. I do not know how many different rudders were produced during the life of the 109, but it is quite likely that one set of drawings will match a specific production batch, whereas another set of drawings will match a different batch. To produce dimensions from source A, and declare source B's different dimensions "wrong", you must be sure that they are referring to the same production batch.

In British terms, the same modification standard.

Anything coming from a flight test origin may be immediately suspect, as a non-standard test item.

Re: Tail surfaces - 109F versus 109E?
 

Well put and absolutely correct.

Re: Tail surfaces - 109F versus 109E?
 

Wow! I can see I should have been more precise!

The manufacturer's drawings I refer to are general layout, not for individual parts. I'm fairly certain that each sub-manufacturer would have received an extremely detailed set of drawings of each and every part they were to manufacture, but while I would love to have a set, I have yet to see anything like that.

So what I have to work with are overall layout drawings, 3-views (some very detailed) from various aviation books, and period photographs. While the drawings thus far posted are extremely helpful in terms of providing dimensional data, the drawings themselves do not seem to be intended to be an exact rendition of the outline of the various parts in question.

From a detailed examination of period photographs (of which most are from an oblique angle and thus of little use) I have found that indeed, even on the same model (like the Friedrich) there are differences from aircraft to aircraft in the exact outline of the aircraft (and so I also would assume the parts themselves to vary, though of course the differences are generally small.)

When I try and them overlay these photos with 3-view drawings from various sources, the differences can be quite striking (in an incredibly anal sort of way.)

My goal is to start with the best information I can find, as I know that in the process of creating the individual parts, I am going to make errors, no matter how slight, which will make the end product less than perfect (as indeed the various sub-manufacturers in the original production lines would have faced this same problem.) What I am looking to avoid is to compound the errors of others, where I am taking their less than accurate rendering of various shapes and outlines and compounding those errors with my errors in the process of creating the piece.

To that end, I need to know what the original source looked like. Even working from period photos (which I differentiate from current photos, as most of the existant aircraft may have been restored or altered in some way) is compounding the errors of the original manufacturer in rendering the parts.

So yeah, I'd love to have a set of draftsmen drawings of the original parts, or save that then a good set of photos of original units, or save that then a set of accurate drawings made after the fact. I'm in the process right now, and at some point very soon I am going to say, "close enough for jazz!" and build my beauty.

So thank you all for exercising my brain and helping to keep the Alzheimer monster at bay, for your information and thoughts. I greatly appreciate it!

Paul

Re: Tail surfaces - 109F versus 109E?
 

From the introduction in 'Aircraft Archives - Fighters of WW2' Vol 1

"The books in this series form a representative group of subjects. Each is a typical example of skill and dedication applied by an amateur researcher over countless hours of translating measurements and photographic interpretation into a multi view scale drawing which, in fact, no manufacturer's general drawings could ever provide! For it may come as a surprise, but the reality is that manufacturers' general arrangement drawings have little value in the factories, are rarely accurate in shape or scale and. without exception, illustrate the aeroplane in a stage long since superseded by production variants. It is the sub-assembly, or component detail drawing, which offers priceless data for the researcher to complete the jigsaw puzzle of any aeroplane."

Re: Tail surfaces - 109F versus 109E?
 

I would definitely agree with all written above but quoted example in the priceless data terms.

it worth of price, but it necessitate really good engineering skills to complete this puzzle and then rebuild a "new bright world with correct general arrangement in 72nd scale" and sometimes this work takes much more efforts than real benefit would have take place at all.

What am i doing now is generating a new set of drawings using assembly plans, general dimensions and photographs for my book in Russian about 109 of different manufacturers (especially G-6 which I'm pointed on) and I definitely agree this is a hard work and somehow a question of trust.

Re: Tail surfaces - 109F versus 109E?
 

It must be pointed out that general arrangement drawings are not the topic under discussion.

It is the accuracy of the sub-assembly or component detail drawings in relation to the production variant.

All the best,

Crumpp

Re: Tail surfaces - 109F versus 109E?
 

Yes indeed, having a set of Emil's rudder drawings under my nose i can say that the rudder construstion is quite a challenge... The rudder profile being absolutly not symmetrical for instance.

Re: Tail surfaces - 109F versus 109E?
 

Hi olefebvre,

That is why we have jigs.
Using them we can produce multiple complex assemblies with compound curves that are exactly the same.

Re: Tail surfaces - 109F versus 109E?
 

Hi Gene,

Out of curiosity do you use some kind of 3D measuring machine to reverse engineer some of parts for which you don't have the exact dimensions (missing factory drawings for instance) ? Or do you rely on more usual and cheaper measuring tools ?

Oli. ;)
Not sure you realised it was me

Re: Tail surfaces - 109F versus 109E?
 

Hi Oli!

I figured it was you. No my friend we rely on much simpler tools. Certainly there is error within the tooling but that level of precision is well beyond what can reasonably be expected.

If you build a jig then parts can be produced that fall within very narrow margins. Certainly not six sigma standards but then again 3.4 defects per million opportunities is well beyond most companies capabilities today.

All the best,

Crumpp

Re: Tail surfaces - 109F versus 109E?
 

Guys, you both have broken my mind. :)

Re: Tail surfaces - 109F versus 109E?
 

Sorry mmoustaf.

:)