AWM Lancaster oddity

[David W3]

A friend spotted an odd feature on the Australian War Memorial Lancaster: there are about a dozen small strakes/strips on the upper surface of both wings near the outer nacelles. They are about half an inch high, appear to be several feet long, equally spaced and running chord-wise.
Neither the AWM or Hendon know what or why they are there and G-for-George seems to be the only example we could find after trawling through our (admittedly Lancaster limited) libraries.
Has anyone got any ideas as to thier purpose?
David

[aerojock]

could they be vortex generators?

[TonyA]

Presumably stiffeners/strengtheners. I've had a quick look through some books and haven't seen these in any pictures or illustrations

[David W3]

Both suggestions are plausible...but why only on G-for-George?
David

[Elwyn]

Similar bracing can be found on his Martin B-26. It was a test bed for the style of landing gear used in the B-47.

http://b-26marauderarchive.org/PH/Noseart/NoseArtP/P671.jpg

[Mudge]

I asked the troops at The Fighter Collection and received this reply:

"Have never seen on a Lancaster before but my guess is that they were to straighten out the airflow behind the engines to improve the airflow over the ailerons. Seen on other aircraft.
Best Regards, Peter"

Mudge the researcher

[TonyA]

I'd still go with strengtheners. They look very reminiscent of the two bars on the upper wing of some Spitfires, e.g. Mk V. They also look to be faired in as if to hide them from airflow rather than being deliberate vertical 'blades' to intrude on the flow. Also, why are they not painted over with the walkway marks? This may suggest they were a late add-on.

[TonyA]

I've now found a reference from the AWM restoration reports on G-George:

The original "Walk Here" markings were found and traced for re-applying. Interestingly, a wartime service modification to the aircraft (involving strengthening strips riveted to the wing above the outboard engines) partially obscures this stencil.

http://www.awm.gov.au/aboutus/conservation/gforgeorge/progress_july02.htm

[bdk]

Maybe a repair after a hard landing?

[peter]

I would lean towards a reinforcing strip(s) Dont forget shes a senior combat veteran!

[Aircraft Mech Paul]

I asked the troops at The Fighter Collection and received this reply:

"Have never seen on a Lancaster before but my guess is that they were to straighten out the airflow behind the engines to improve the airflow over the ailerons. Seen on other aircraft.
Best Regards, Peter"

Mudge the researcher

Guys,

I gotta go with the reply from Mudge on this one. The reason I say this is because the British have always been fanatics with repect to aerodynamics on large aircraft. Case in point. The BAC-111. If you look the wing there is what they call or rather what I refer to as the "Potatoe Chip"....is is about 1/3 of the way outboard of the fuselage and it improves direction airflow over the wings and allows a smoother intake for the tail mounted engines. The DC9-10 is simliar....and I beleive neither has Leading Edge slats for increased lift on take-off and landing. The Boeing 757 also has similar vortex generators on the upper surface of the wing.

Additionally, if you look the placement of the strips with respect to what rivet patterns I can discern from the photo, they do not appear to be part of any repair or internal strengthening. So this is, what I think at least, and experimental protoype R&D thing of the day techologically speaking.

Just my two cents though,

Paul

[setter]

Hi

I was told that they were for airflow and I discussed the fact that they are not on any other Lanc I had seen and was then told and shown a pic that they were on the other lanc to come to aus in WW11 (later scrapped ) and on the Yorks and also on the Tiger force modified Far east Lancs. The problem was that virtually no lift was provided behind the engines as standard and these "Fences" reinstated the lift

None of this makes any sense to me without paperwork etc and as it is a mod it should have had paperwork. I can tell you from very close inspection that there is no way they would provide any strenghtening given the flimsy attachment process.

Interesting and warrants some investigation. Surely we have some Lanc Wizard on here who can enlighten us ?


Regards
John P

[lone avenger]

Maybe someone can contact the RAF Memorial Flight or the Canadians with there airworthy examples someone must know the answer for sure!

[peter]

This might clear things up. From two Lancaster teams.

.....Seem to recall this being discussed on the net and the general concensus was that it was strenthening of some sort. It's too low in profile for an airflow aid and I also note it's been added post spray painting of the camouflage and walk here lines.Seem to also recall that in all the discussions this was the only Lanc that has been noted with such "additions".

.....I can only think they were for strength or air flow. As
a matter of interest, the strips are metal, with wooden 'tips' at each end.