Lysander spats shape?

I’m still not convinced that it is just an optical illusion. After studying all the images a bit more something else just struck me. In JDK’s original image, the ‘longer’ spat clearly shows the scuff marks on the two kick-in steps that are present, but on the ‘shorter’ spat I can only see one scuff mark. Can we conclude from this that this spat only has one step? We’ll have to ask Mr. Kightly to closely scrutinize his images once more to see if he can come up with that second step. :rolleyes:

this one also appears to be the “short type” – but then I also think it could be an optical illusion…

Martin

I’m confused. I’ve only ever seen the long ones and wasn’t even aware the was any other type.

You aren’t alone Mike 😀 My view, supported by Brian’s very useful photos indicates that it can look like there are two types, but only one, depending on the angle of view. But I might be wrong, and there was a ‘short’ spat fitted to some aircraft of differeng marks. See the problem?

Many thanks Brian.

I’m confused. I’ve only ever seen the long ones and wasn’t even aware the was any other type.

James

Apologies for the delay in replying on said subject but my motorbike went u/s just before the Duxford show and as I was intending going on the Sunday any way……… Enough said.

Any way, as there was wall to wall sunshine today I had a quick spin down the A14/M11.

As I thought, the Lysander was not exactly in the right position to get the required photos as I could not get far enough back and the fuel tank blocked the view. So I improvised. I lined up on the far wheel and Photo A was taken kneeling down. Photo B was halfway to standing and Photo C at full height. Photo D I took one step to the left and Photo E one step to the right. They do not actually, in my opinion, show very much. I needed to be further back.

Photos F & G.

These were taken at Elvington this year just after it had landed and before it went u/s. Photo F is taken slightly from a front view and Photo G slightly from a rear view as it moved passed by me.

Although greatly exagerated, to my eye, they show two different shapes of spat although they are of the same aircraft at the same time. To me, Photo F is the equivalent of the red outline, long and thin, in your original post and Photo G of the green, tall and squashed. As I said in my first post, the red and green spats were taken at different angles and height which accounts for the different shapes.

Hope this is of help James and thanks for the compliment in PPrune.

Brian

if they were press moulded, I wonder if they got a mould wrong without the time to fix it, it was just used?

hence the very small number of aircraft obviously fitted with these spats?

Thanks chaps – good ideas keep them coming.

TT, I don’t think so. It would have come up in research so far (mine or someone else’s) I think, though it’s possible.

Factories. There were two builders in the UK, (Yeovil & Doncaster) one in Canada, with many Westland built machines going to Canada, as well as the ‘native’ machines.

There could be something in it.

I think the spats were press moulded, but I’m not sure. They are made up from a number of seperate pieces, with a large door for the gun breech, and smaller panels / patches and steps let in, and with the two wheel covers held with Dzus fasteners.

Just a thought but the difficulties associated with Spats are well known – ie clogging, damage on landing/taxying etc – could there have been an in service approved mod at the aerodrome to repair/replace/fix the spats? Which could explain the variation – ??

tt

JDK,

Another point to note:

Manufacture variability. It is noted that different factories built the same aircraft slightly differently.

I do not know how many factories the Lysander was built in, and as you say, there seems to be no rhyme or reason.

Given that, I would suggest that the ‘design’ of the spats was interpreted differently by different people.

When I say ‘design’ I mean that, while the factory drawings say one thing, the wo/man on the floor actually does somthing different.

I take it these spats could get damaged easily, so could well have been replaced with a pair (or even only one? )with a variation in shape.

I don’t know how the spats were manufactured but there are plenty of reasons at the manufacturing stage for the actual shapes to change a bit, over what was drawn at the design stage. This still happenns now, but we usually have the time to update the drawings.

I think those two pics do show different spat designs, but as PP says, pics can display things slightly wrong.

coanda

VC10 – we must have posted at almost hte exact same time, with the same thoery……………..spooky!

Just from the photo’s JDK posted, I would agree that they are two different shapes. The height difference between the two is negligable if you are comparing lengths, and the difference in angle doesn’t seem to be more than 2 or 3 degrees. Anyway, I too am looking forward to seeing the results of your experiment Pen Pusher!

I just thought of another quick and dirty theory. I don’t know where Lizzies were built, but say that there were two or more locations, one could have used a different mould for manufacturing the spats. The parts would probably have been interchangeable which would explain seeing them on different aircraft.

Cheers James,

he owes me a pint cos I was right (you heard it here first folks …. 😉 )
didnt make it clear above but i thought they were LSCs…blooming complex bits of kit they are too

So if anyone out there knows of the whereabouts of any Lizzie wheels Mike Terry @arco would love to hear from you!

All the best

TT

Hi TT,
The Dowty internally sprung hub is rare, I’m unaware of any but the Glad or Lysander using it – and it’s held up three restorations I know of, and is an example of the extra challange facing airworthy restos as against static.

The racks fitted to the stub wings (and under the rear fuselage) were standard light series carriers, but other racks could be fitted to the stub wings as well, or instead, for heavier stores.

I do know that Lysander wheels are very complex and internally sprung – certainly the DX boys were on the look out for some – not something I was aware of until i spoke to them – they said they could find something ‘to fit’ but it wasnt quite the same and that remanufacturing the originals would be horribly expensive…

Talking of Lizzies i was chatting to a Museum member at the weekend and I am pretty sure that the winglets mounted on the spats were complete with bespoke bomb racks – or did they take the standard light series carrier as fitted to Blenheims, Walrus even Tigers etc – we have on on show at the Museum (ex harvard)

TT

No problem James. If I had seen this thread earlier I might have been able to solve the problem as I was at Old Warden yesterday and I could have used their Lysander.

Brian

I think you are right Brian, and I’d appreciate seeing the results of the experiment!

As someone who uses a lot of photographs as reference material for scale drawings, to me the difference is an optical illusion and I would not use those two photographs to compare spat shapes as they are taken from different heights and angles.

The red outline spat is more of a side view shot as can be seen by the shadow of the wheel spat in the background. The green outline is taken from a higher angle, more rear spat, and that could quite easily distort the image as you are looking down on the spat and it would then be elongated and compressed. Perspective comes into play here. That is just my interpretation of the photographs

Out of curiosity and as I will be going to Duxford this weekend I will try a photographic experiment on their Lysander, if it is in a convenient location, and see if I can recreate the same images.

Brian

Thanks chaps.

I’m not as sangine as you that someone will come up with the correct answer…

Mud. No. The side doors were often removed to avoid mud buildup in France in 1940 and in Canada to avoid snow packing. But the length of the spat never seems to have been a reason.

The stub wings were attached to the undercarriage beam, and could be removed or attached as required; so I can’t see any reason for a different length spat as well.

Streamlining. An interesting idea, good point. However I can’ty see the length on the Lysander would be critical enough to make a real difference. A possible theory is that the tailplane was getting buffet from desturbed air when in the landing position. However the ‘short’ spats seem to appear on all sorts of aircraft at all sorts of periods. And I’m not convinced there’s two lengths. It could be an optical illusion.

I should add that the Lysander in the pic is the ‘Blackburn Steiger’ wing test aircraft, so may have been modifield in other ways for other tests.

Thanks for the thoughts, chaps!

I never noticed, nor gave a thought to, the stub wing! :rolleyes:

Lengthening a spat or nacelle is usually done because the shorter variant suffers flow seperation at the end which increases the drag of the design. For an example of this look at the engine nacelles of the prototype Mosquito. Just from looking at those two shots the only thing I can say is that they do appear to be lengthened, and drag reduction would be a logical reason for this.

Is the longer spat in some way linked to the stub wing that can be seen in the top left shot? The stub wing installation must have meant installing a different spat, perhaps they lengthened it at that point to optimize the flow around it, which will have changed because of the stub wing and the stores carried on it.

Just my thoughts from looking at that photo for 20 seconds, I’m sure someone else will come up with the real reason 😉

The spats weren’t modified for some kind of ground clearance or serviceability reasons, were they? I know some aircraft (the Bf109, for instance) had their undercarriage doors removed to stop them getting clogged and damaged by mud.

Best I could think of, anyway. :rolleyes: