Wheeltracks
 

I have just finished yet another book which states that the wide track undercarriage on the Hurricane made it much easier to handle on the ground than the Spitfire.

When I was at Kemble airshow last year, I had the pleasure of examining R4118. Parked alongside was Sherringham's Spit 1. I noticed that the difference in wheeltracks between the two aircraft did not appear that great.

Taking measurements courtesy of my size 11 boots indicated a difference of less than one foot. I cannot seem to find the early spit's wheeltrack dimension on t'internet. Google quotes the Hurri's track as 7 feet 10 inches. Anyone enlighten me?

To me, the difference seems so minor as to make a mockery of the terms 'wide track' for the Hurricane and 'narrow track' for the Spit.

Am I missing something here?

I, like many others probably accepted the narrow wheel track thing, but on reflection it may be more a case of where the legs attach to the airframe. The Hurricane legs actually attach outboard of the mainwheels, whereas the Spitfire legs are noticeable splayed out providing an effectively more narrow base. Like trying to balance on a pyramid as opposed to an oblong
Maybe someone with access to the real thing could whip out a tape measure?

Whereas the Bf109 had its undercart attatched to the fuselage... so that the wings could be removed. :ok:

Please tell us you didn't really mean that...

While not having had the good fortune to fly either, I can verify that a small difference in track width can have a large effect on docility of ground stability/crosswind landing comfort. I have quite a few hours in both Tiger Moth and the Thruxton Jackaroo variant which had a 12 inch spreader to increase the track (to match the increase in fuselage width).

The 'roo was much easier to handle in crosswinds where one would have been looking for a dead into wind field in the Tiger.

I am a bit confused too. IIRC, the Spitfire's gear was hinged inboard so the gear extended down and toward the fuselage. The Hurricane's was hinged outboard so the gear extended down and away from the fuselage. Surely this must give the Hurricane a substantially larger track.

Synthetic.

I thought so too. But when you take into account the Hurri's wheels are almost touching when in their wells and when extended they are angled straight down, then the wider attach points on the Spit and the splayed legs equals not a lot of difference in track.

I will make a couple of telephone calls tomorrow to a certain two people at Duxford who can give us a definite measurement of the early Spits wheeltrack.

You don't think this could be just a piece of 1940 Spitfire snobbery that has been perpetuated for 70 years? :}

As Kitbag said the wheel track is only part of the story, the other very important bit is where the legs are attached.

To appreciate this imagine two aircraft with the SAME wheel track but on one the legs hang staight down (like Hurricane) and the other has the legs pointing inwards (like Spitfire) BUT in the inwards case the legs point so far inwards that they meet on the centreline.

Now imagine you are travelling over bumpy ground and one leg hits a bump. In the case of the H the aircraft upward force would change its bank angle a lot. In the case of the S the upward movement would be applied at the centre line with clearly different results.

Any help?

@ProofReader

I've been trying to imagine this myself. But isn't it in fact the other way round? On the Hurricane, a bump of 1 foot will raise the midpoint of the wing 1 foot, and hence the fuselage less, whereas on the hypothetical S-type, a one foot bump would raise the fuselage the whole foot. So that a given size of bump is more likely to tip the opposite wing-tip into the ground on the S-type than the H-type???

???s because I find this stuff hard, and I may well have got it wrong, but hope someone will explain how I'm wrong.

Measurements in Imperial, not metric, because these aeroplanes think in Imperial.

PR and FP,

I think you are bumping in the wrong direction ;)

To simplify thinking about this, I am going to ignore any oleo compression effects and imagine that the wheel is rigidly fixed to the airframe by the gear leg.

Then if one wheel is raised by 0.3048 m due to a bump, then the wing rib directly above the wheel is also raised by the same amount. It is completely independent of where the gear leg is attached.

Quick and Dirty method
 

Talk to someone who's a model builder and borrow made up kits of each. Compare them belly to belly and see what you get....
:8

Gentlemen,

This might help - no models, the genuine articles.

On my computer, they have been accurately scaled together using the Hurricane wingspan of 40' and the Spitfire 36' 10".

The yellow overlay is the wheel track of the Hurricane superimposed on both aeroplanes.

http://i636.photobucket.com/albums/u.../spithurri.jpg

Nice one - any chance you can superimpose it on a Bf-109 & FW-190?

What % of 109's were lost in landing accidents?

Sure can, but you will have to wait until tomorrow I'm afraid.

Do you mean the FW and Me together, or one of them compared with the Spifire or Hurricane?

PR and FP,

"I think you are bumping in the wrong direction

To simplify thinking about this, I am going to ignore any oleo compression effects and imagine that the wheel is rigidly fixed to the airframe by the gear leg.

Then if one wheel is raised by 0.3048 m due to a bump, then the wing rib directly above the wheel is also raised by the same amount. It is completely independent of where the gear leg is attached. If referring to a wing rib, it is completely independent. However, it depends on where the rib is relative to the wing, or aeroplane."

--------------------

Raising a rib that is twelve feet from the centre line a foot is going to affect the whole aircraft less than a rib that's only six feet away.

Numbers made up, I haven't a clue what the difference in mounting points is.

Hurricane u/cart
 

I think the Hurrricane u/c gave greater prop clearance and also the wider track made the brakes more effective for taxying / keeping straight after landing, remembering that both types had no tail wheel locking or a steerable tailwheel so relied on independent braking action especially in a crosswind.
A wider track u/c also gives better weight distribution;another helpful (stabilising factor) input in a crosswind situation.

Well the Fw had a wide landing gear and the Bf a very narrow and had an horrific accident record whilst landing / taxiing. So comparing both to the H & the S might be interesting.

With regard stability during / on landing - don't most books mention also the H having excellent flaps...?

I vaguely remembered a post from Andy Sephton on the FlyPast forum comparing the two and I was shocked how long ago it was.

It's more regarding landing than taxying but his comments surprised me.

Key Publishing Ltd Aviation Forums - View Single Post - Hurricane vs Spitfire

Page 73 of "Spitfire - The History" ( Morgan and Shacklady) gives a figure of 5.71 ft.

http://img193.imageshack.us/img193/2418/clipboardbw.jpg

I also have that figure...

http://img4.imageshack.us/img4/4280/img083qk.jpg

Hurricane v Spitfire ground handling.
 

I was surprised at the comments on the Shuttleworth Hurricane, but then of course one has to remember this is a Sea Hurricane with a mighty V Frame Hook at the end of the fuselage that no doubt alters the C o G on this particular one.
No other Hurricane flight test/ Handling notes seems to have concerns with a Hurricane in this respect, and in fact i remember Viv Bellamy who flew both types during and after the war describing the Hurricane as a fighter a club pilot could fly with a proper check out.