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Onan the Clumsy
19th May 2005, 20:51
Why does the Me109 have struts on the horizontal stab?

Offhand I can't think of any others - a few with wire braces perhaps, but none with real bona fide struts.

treadigraph
19th May 2005, 21:49
Dunno, obviously structural, but it was a right give away in the formation beind Tim Mill's "Oh Gawd Strewth" Hurricane in "Battle of Britain"!

Once one's attention had been drawn to it of course... :p

TwoDeadDogs
19th May 2005, 21:54
Hi there
The models up to the "Friedrich" had struts. The "F" models had tail-tears-off-in-flight trouble in the early examples but this, like the later Typhoon, was modded out. The "G" and subsequent models never had struts, but did have tweaks like taller tail-legs, taller wooden empennages and clear-view canopies, as well as bigger guns, engines and less pleasant handling characteristics.
regards
TDD

Kolibear
20th May 2005, 08:17
I was under the imprssion that a strut supports something, whereas a tie holds two object together.

In this case, I think that the 'strut' is actually a 'tie' and is used to transmit aerodynamic loads, ie lift, back to the main fuselage structure.

It probably means that the original horizontal stabiliser structure was a bit too weak and adding a tie was a quick fix to strengthen it.

In the case of a Cessna 150, it may be that the 'strut' supports the wing when its on the ground, but then acts as a 'tie' when the aircraft is in the air. It may be less draggy and lighter to have a strut than to have a bigger wing structure.

H.Finn
20th May 2005, 18:18
BF = Bayerische Flugzeugwerke, as far as I know. Otherwise correct to call it Bf 109 instead of Me. And it is Messerschmitt, not ..schmidt...

PPRuNe Pop
20th May 2005, 18:47
Ah well that's sorted then.

But the aircraft with the 'support' struts is the Bf109E - as flown by the great Adolf Galland - and many other German aces. After that came the 3,4 and so on.

TwoDeadDogs
20th May 2005, 22:15
Hi all
With regard to the ME/Bf thing, any wartime account you'll read of will say "ME-109", more often than not. Also, are there not pictures of drop tanks and gunpods stencilled with "Fur ME109"? At this stage, everyone knows which aircraft you're talking about, regardless of whether you insist on Bf or not.
All the best
TDD

Unwell_Raptor
22nd May 2005, 20:51
I seem to recall from my youth when I read everything I could get hold of about the war, that the Bf109 required many fewer man hours to build than the Spit, which was beautiful an aerodynamic, but a bugger to make. The 109's design cut a few corners, but that's how the Germans could keep churning them out in caves in 1944, using a lot of slave labour.

Blacksheep
23rd May 2005, 02:25
S'funny, but the BoB pilots from north of the channel seemed to refer to them as Me109s or more often just 109s. They were meticulous about the 'E', 'F' and 'G' suffixes though. From a protagonist's point of view it was more important to be aware of your opponent's performance and armament, rather than who designed their machine.

In "First Light" Geoffrey Wellum DFC comments on the tendency for German aircraft to break up in flight when pushed - whole tails coming off etc. - was this perchance, a result of all that cutting of corners? :suspect:

JDK
23rd May 2005, 06:59
Had a look at a pic of the prototype Hurricane?

Struts. And a retractable tailwheel. Interesting changes for production. Lost the struts (good) and the retract (and add an underfin).

Kolibear is correct speaking as an engineer, but the stick thingies under the tailplane of the Me109, Hurricane prototype, Walrus etc. etc. are usually called struts, not ties. I think we defer to useage rather than engineering accuracy.

'Me' vs 'Bf'. Upto 109G should be 'Bf': During the 109G production it changed to 'Me'. (My understanding.) Bear in mind that Messerschmitt was IIRC the only manufacturer who din't have the 'maker-initials-number' setup of the RLM; you can understand everyone in general and enemy use then, and now forcing the term to 'fit'. As Willy was such a politician, I'm sure he had a hand in fudging it too.

Messerschmitt structures. The back end of the 109 was based on the 108 concept - it's not just war films that mix the two up! As the 108 had struts, I'm wondering if that was a design carryover? Bit of a poor effort by Willy either way. The segmented pressed half chunks was a brilliant piece of design though.

Also, unlike RJ Mitchell, he did design the 109 to be built by a factory. Without Joe Smith of Supermarine redesigning the Spitfire for production, rather than handbuilding (something RJ unacountably overlooked) the Spitfire wouldn't have been in with a shout for the gloryhunting.

And n'th level of BoBF triv - the struts on the Buchons are dummy (of course) as the Buchon is a 109G with a Merlin - no struts on the G - so they didn't need them on the 'Hurryons' or 'Buchaines' anyway - just a lack of time to mess about taking them off the 'Messerschmitt Bf109Es' they were 'acting'. Funny they painted them in RAF colours then worked hard to stop people taking pics. There's lots of related facts at: Falcons109Lair (http://www.me109.info/index-800.php)

Cheers!

treadigraph
23rd May 2005, 08:13
Thanks for that JDK, you just answered a puzzlement - I was looking at pics of various Buchons (most of which I think acted in BoB the Movie) on Friday and thinking "but they aint got no struts..."

:ok:

TwoDeadDogs
23rd May 2005, 09:40
Hi all
Were any of the Spanish Buchons built from original German airframes?
Were the cannon fitted in the film genuine or just dummies.? I thought the G model couldn't carry internal cannon. Does anyone know of a millionaire willing to convert a G model to a G-12 so we could all have a go in a 109!!
regards
TDD

JDK
23rd May 2005, 13:29
What a chap you are for questions TDD!
Were any of the Spanish Buchons built from original German airframes?

Depends who's buying. :cool: (Briefly) The German's shipped a batch of 109G airframes to Spain, but were losing the war, so the engines never arrived. After being built up with Spanish engines, a batch were later still re-engined with Merlins, making the much loved character actor, the Hispano Buchon. A number of restorers and owners on occasions have claimed that their Buchon was German built. Well, you would, wouldn't you? :rolleyes:

Were the cannon fitted in the film genuine or just dummies.?
The Hispano Buchon was armed with 2 cannon in the wing, the barrels protruding about 2ft with an unusual flattened fairing over them. The spinner was pointed, and the Merlin is famous for many things including the lack of a cannon. Perhaps we should upbraid RR for an oportunity missed. :hmm:

For the record, the film Buchons had the wingtips clipped (though not to the end of the mainplane, like the 109E, but about 1/2 of the rounded tip - why? Dunno. Handling would be a guess) the cannon and wing fences removed, a hole added to the spinner, dummy guns added to the wing and in fairings on the top of the cowling, and tail struts. All flying film Buchons had 4 bladed props, but some taxiing ones in the film and more modern warbird versions have DC-3 three-bladed props fitted.

And the triv corner - A two seat Spitfire was fitted with a Buchon prop during the filming, after a Connie Edwards belly landing IIRC. Don't know how that flew. There was one two seat Buchon with a 109K style tail, though it's believed that it was a Spanish designed rear... Extra points for spotting that one in the film! Famous shots of Tuck & Galland in it.

Connie is your man for Buchons, then & now, owning a good percentage of the world population and the only two seater - still in their BoBF colours, in a hanger, in Texas.

The Confederate Air Force were buying Buchons from the Spanish when the film was under development, and Hamish signed them up, aircraft & all - well, you would, wouldn't you? Spitfire Productions bought the Spanish AF stock of Buchons, which had just been retired, hired the 'He111s' which were still in service, bought two of them and brought them to the UK for filming. Who owned what during the filming I don't recall, but after the filming Lloyd Nolan, Connie and (one?) other CAF chap bought a selection of a/c. During the filming they were hired by Spitfire Prods.

This is all secondhand from my good and much missed friend the late great Robert Rudhall (if you liked the film, track down the books) and another chap who posts here sometimes, BobFilm authorities. I just tag along...

Cheers!

saman
23rd May 2005, 18:52
In my book Kolibear is right, a strut supports load in compression and a tie in tension. So methinks they're struts under the Me/Bf 109's tail and ties under a Cessna 150's wing!

In my early training, I was taught that, in 1g flight, the load on tailplanes is not vertically upwards but vertically downwards. The centre of gravity (cg) of aircraft with tailplanes (rather than canards) is forward of the centre of lift (CoL) and thus needs a tailplane download to balance it out and give stability. Control inputs through the elevators can change that. One would expect the critical load to be that of pitching the aircraft nose up; so a combination of the load to balance the cg and the control load to pitch the aircraft - that's a big tailplane download and thus the 'struts' are in compression.

Aircraft with 'neutral stability' - mostly the new-ish highly manoeuvrable fighters - have cg and CoL roughly co-incident and thus very small tailplane downloads but are horribly unstable to fly and really only work with fly-by-wire.

That does not mean all FbW aircraft are like that; civil FbW airliners all have good natural stability (cg fwd of CoL).

Aircraft like the Airbus A310-300 and A340 have a tailplane tank and pump with a sophisticated control system which, within the constraints of a stable aircraft, allows the cg to be as far aft as possible to both minimise the trim drag from the tailplane download and reduce the induced drag from the wing since the overall lift requirement is less with a lower aerodynamic tailplane download.

Sorry if I've gone on a bit...

Eric Mc
23rd May 2005, 21:58
Regarding the tailplane "struts", they were a feature on all 109s up to the F model.

Up until 1941/42, Messerschmitt was the chief designer for the Bayerische Flugzuegwerke, hence the "Bf" prefix to his designs. He was eventually allowed to use his own "Me" prefix when he acquired full control over the manufacture of his designs.

Over at Focke-Wulf a similar situation arose with Kurt Tank. Initially, planes he designed retained the old Focke -Wulf "Fw" prefix but eventually his designs were alloted a "Ta" prefix - as in the Ta-152 and the Ta-183.

Onan the Clumsy
25th May 2005, 19:01
Thanks everyone for some fascinating replies


JDK, can you speak further on this:The segmented pressed half chunks was a brilliant piece of design though

To add my own - and unrelated - trivia, I heard that all three of the tail feathers on the Piper Pawnee were the exact same part.


Ties or Struts? Iin the interests of harmony, I shall call them Tuts...


...unless of course some argumentative "person" want's to call them Sties :E


edited because, after all, this isn't JetBlast :cool:

JDK
26th May 2005, 03:25
Well spotted Onan,

I was typing fast so's no-one would notice the lack of technical speak.

I will try to do better. :cool:

The rear fuselage of the 108 and later the 109 was built in segments. Imagine the fuselage. Now divide it in half like a model kit. Now chop each half into pieces, at each 'station'. The clever bit is that each piece was lapped to fit inside the next, and to provide a joggled joint. So just by assembling the half from its segmenys, you had a very strong shaped piece, without any frames, as the lipped edge acted as a frame itself, while also holding the next piece.

It's hard to describe, especially when one ought to go and look it up! If you can track down a photo of 109s under construction, all will be revealed!

HTH

treadigraph
26th May 2005, 08:17
Onan, you sure about the Pawnee's tailfeathers? Thought its R S end was all Super Cub DNA.

There certainly was a light aircraft that had that feature, Bolkow Junior keeps springing to mind but I'm not sure I'm right there.

Onan the Clumsy
26th May 2005, 18:25
not sure no, but reasonably sure I was told it was the case

:confused: