Me 109 mediocre roll rate at speed (2 Viewers)

[spicmart]

The roll rate of the 109 is said to not compare too well to other fighters of similar weight and dimensions such as the La-7 or Yak-9/3. Even the Spitfire with its much larger wing outrolls the 109 in many flight regimes.
Apart from a single-spar construction, large wing cutouts for landing gear, radiators and flaps, another cause of this is apparently that the 109 wing (from the F-version onwards) has a relatively large tip so that the aileron does not extend to the end of the wing.
Might it have been possible to rectify this flaw, at least partly, by extending the aileron further as seen in the sketch?
What do you think?

Pardon the amateurish sketch.

 

[PAT303]

Winkle Brown talked about this in one of his books, after flying a captured 109 during the BoB he mentioned the controls stiffened up to the point of being locked above 400mph.

 

[GregP]

The wingtip on the Bf 109 is held on by 2 small bolts and is not much, structurally. If you want to cantlever the aileron ... maybe. If you want another hinge, you'd need to put some structure in the wingtip. As it is, the wingtip is NOT structural at all.

 

[PAT303]

One of the improvements made to the Spitfire was to replace the fabric control surfaces with metal and change to piano hinges but what made the biggest difference was reprofiling them. Instead of making major design changes fixing what you have could be the better option.

 

[spicmart]

The wingtip on the Bf 109 is held on by 2 small bolts and is not much, structurally. If you want to cantlever the aileron ... maybe. If you want another hinge, you'd need to put some structure in the wingtip. As it is, the wingtip is NOT structural at all.

The main spar should be extended to the end of the wingtip as well as installing some more carrying structures there.

 

[Jaivan]

Large-span aileron where tested as part of the F-series development, with both the early semicircular wingtip and the final elliptic one:

The aileron effectiveness was found better than short-span ailerons (no quantitative details given), but with worse behaviour at low speeds (for example, considerabily higher stick forces than Bf 109 E-series).
A photo of the first type installed in W.Nr. 5603 can be found here: Falcons Messerschmitt Bf 109 Hangar - Photo view - PhotoID: 134

Either way, it wouldn't have increased the roll rate at high speeds. As FB Nr. 1951 demonstrated, the problem lies in the low torsional stiffness of the Bf 109 wing structure, with the associated loss of aileron effectiveness.

BTW, there is only anecdotal evidence for some of the aircraft you mentioned (La's and Yak's), so an exact comparison at high speeds is purely speculative.

 

[Jaivan]

One of the improvements made to the Spitfire was to replace the fabric control surfaces with metal and change to piano hinges but what made the biggest difference was reprofiling them. Instead of making major design changes fixing what you have could be the better option.

Actually, metal ailerons were tested in the Bf 109 in at least two occasions.

The first one, in W.Nr. 5604 (VB Nr. 109 20 E 41 Blechquerruder Me 109 F, 20.9.41), to avoid the ballooning/deformation of fabric-covered ailerons with speed. The extra weight (0,8 kg) of metal-covered ailerons caused balance problems at low speeds and small deflections (vibrations in control column). It was found much more effective to reduce the distance between aileron ribs to 200 mm in the fabric-covered ones.

The second time was in W.Nr. 110039 (VB 109 15 E 44 Fertigungsverbessertes Querruder, 27.08.1944). It was one of the 4 different ailerons tested as part of the Bf 109 flying qualities improvement program carried out from mid 44. The aileron was metal-covered, with a rounded nose and with a Flettner tab (slightly bigger than the one already tested in some Bf 109 G). It had been developed for the Bf 109 H-2 series, but it was decided to run a parallel test on Bf 109 G series. Tested up to Va = 750 km/h @ 2 km, it had very low control forces. It was, however, discarded for further testing in October/November 44 (probably linked to the final cancellation of the Bf 109 H, which happened around this time).

 

[spicmart]

Actually, metal ailerons were tested in the Bf 109 in at least two occasions.

The first one, in W.Nr. 5604 (VB Nr. 109 20 E 41 Blechquerruder Me 109 F, 20.9.41), to avoid the ballooning/deformation of fabric-covered ailerons with speed. The extra weight (0,8 kg) of metal-covered ailerons caused balance problems at low speeds and small deflections (vibrations in control column). It was found much more effective to reduce the distance between aileron ribs to 200 mm in the fabric-covered ones.

The second time was in W.Nr. 110039 (VB 109 15 E 44 Fertigungsverbessertes Querruder, 27.08.1944). It was one of the 4 different ailerons tested as part of the Bf 109 flying qualities improvement program carried out from mid 44. The aileron was metal-covered, with a rounded nose and with a Flettner tab (slightly bigger than the one already tested in some Bf 109 G). It had been developed for the Bf 109 H-2 series, but it was decided to run a parallel test on Bf 109 G series. Tested up to Va = 750 km/h @ 2 km, it had very low control forces. It was, however, discarded for further testing in October/November 44 (probably linked to the final cancellation of the Bf 109 H, which happened around this time).

You seem to know quite a bit about the Me 109.
So I'd like to ask if you have heard about this particular machine (and maybe know more about it):
Thread 'Much improved Me 109K?' Much improved Me 109K?