Author Topic: Bf 109-K (Read 917 times)

HoHun · « **Reply #15 on:** January 03, 2003, 05:31:06 PM »

Hi Kweassa,

>just what exactly is a "Flettner Tab" ?

A Flettner tab is an auxiliary control surface. Control inputs deflect the the Flettner tab, creating a force that assists in moving the primary control surface.

The amount of assistance depends on the exact design of the control linkage. In the extreme, it's possible to have no linkage to the primary surface at all - the entire control force is generated by the Flettner tab then. (Shorts actually built some flying boats that way.)

How the Flettner tab works is easy to understand if you see its initial implementations - it was just a small wing suspended rigidly from the primary control surface and riding right behind it.

With a Fletter-assisted rudder, when the pilot pushed the right pedal, the Flettner tab would be deflected to the left. As the Flettner tab was a little wing, it would aerodynamically create a force to the right. Since it was connected rigidly to the main rudder, this force would deflect the main rudder to the right - the direction desired by the pilot.

Flettner tabs were used because they made it possible to create much larger control forces than human strength could provide. Without force assistance, it would have been necessary to reduce the stability of large aircraft to get low control forces, which was not a way of designing safe aircraft :-)

Stability was the reason for not always relying on the Flettner tabs alone. Balanced controls were fine, but if the control forces became too small, oscillations or loss of control could result when aerodynamic forces became strong enough to move them against the will of the pilot.

The inventor Anton Flettner had a nautic background, and the Flettner rudder was employed with ships as well as with aircraft (starting in the 1920s). Among his other inventions was the Flettner rotor ship which used large upright rotating cylinders as sails (which, unlike often stated, worked perfectly). Flettner also contributed to the development of practical helicopters, designing the Fl 282 and Fl 285 Kolibri observation helos for the Luftwaffe and working on a large transport helo at the end of the war.

Regards,

Henning (HoHun)

MiloMorai · « **Reply #16 on:** January 03, 2003, 06:00:09 PM »

Quote

Originally posted by Rollio
From what I've heard the biggest gain from having a 109k over a g-10 would be improved roll rates at high speeds (due to the aileron improvement), and a mk103 centerline gun option. A Ta-152 with a mk103 would rock too.

Are you sure about that MK103?

The MK103M(??) was tried. Note, the MG151 was supposed to be there according to some authors.

HoHun · « **Reply #17 on:** January 03, 2003, 07:10:41 PM »

Hi Milo,

>Are you sure about that MK103?

The MK103M(??) was tried. Note, the MG151 was supposed to be there according to some authors.

The MK103 was the desired weapon for the Me 109K, but it had to be re-designed to fit between the cylinder banks of the Me 109's engine which wasn't finished in time for production.

The MG151/20 certainly was not used in the Me 109K-4, though the normal gondola cannon Rüstsatz was available for the Me 109K as well, for some reason under the R4 designation.

The planned Me 109K-6 would have had an integral 30 mm MK108 in each wing. The Luftwaffe at first planned bomber destroyer units to have the Me 109K-4/R6 (referring to the gondola cannon Rüstsatz which was R6 for the Gustav), but later dropped them in favour of the Me 109K-6 which was never built.

In late 1944 and early 1945, the K-6's cannon wings were tested at Tarnewitz on an old G-6 airframe, and the Messerschmitt factory at Wiener Neustadt was scheduled to produce the K-6, but the war ended before it came to that.

The cannon wing would have been able to take two MG151/20 instead of the MK108 (which probably gave birth to the popular myth of the K-4's cowl MG151s), but it seems this variant existed on the drawing board only.

Regards,

Henning (HoHun)

fats · « **Reply #18 on:** January 03, 2003, 07:43:33 PM »

The Rodeike book says few K-4 were delivered with MG 151/20. No idea what's their source on that.

// fats

MiloMorai · « **Reply #19 on:** January 04, 2003, 05:33:33 AM »

Henning, yes I know all that;) but thanks. I believe it was Green who started the myth of the K-4 with the fuselage weapons mentioned as standard.

humble · « **Reply #20 on:** January 06, 2003, 04:28:20 PM »

The K series 109 was agreat dissappointment to those who flew it, it had serious handling issues at high altitude. Somewhere here I posted a little clip on one flight where a JG26 pilot had to bail (from 30k) and then listen as all three other members of his flight augered in from 30k due to same problem. The 109G10 AH has was the final model which had the engine upgrade minus the specific hi alt modifications which caused the problems...only thing I think would be nice is a K14 (I think) with the buble canopy.