Perhaps the Spitfires accident rate on take-off and landing did not warrant modifications to this design weakness. Of course, all designs are a compromise and the landing gear lost out a bit.

Please explain – what leads you to suggest the Spitfire’s outward retracting undercarriage was/is actually a “design weakness”?

Sure the early Spitfire u/c wasn’t up to carrier-operations, but that is a classic case of the original design being put to a use which was not anticipated, and I believe the problem was nothing to do with the retraction direction, but more to do with the higher vertical speeds involved when the aircraft hit a pitching deck – again, the design was being asked to handle a situation for which it was not originally intended.

I am not aware that the Spitfire sufferred a significantly higher accident rate (pro-rata) on take-off or landing than the Hurricane (or any other fighter with inward retraction)? The problems with the Bf 109 design are well known, in that the narrower undercarriage track and “significant” toe-in (or out? My memory has failed me again!) of the wheels tended to cause problems as the pitch attitude changed during takeoff or landing, which was further compounded by any crosswind or rudder- or torque-induced yaw.

However, the fact that the 109 undercarriage was mounted directly onto one of the main fuselage frames probably meant fewer 109’s ended up with their undercarriages “punched” up through the wings during heavy landings than did Spitfires, where the legs are mounted on the wing spars. So how do you define a “weakness”?

When used as intended (i.e. a land-based fighter), and at the original design weights/speeds, I am not sure the Spitfire undercarraige was ever actually a design weakness was it? Have you any proof that proportionally more Spits than say Hurris sufferred accidents due to their undercarriage designs, excepting the early Seafires, where the “weakness” was more down to the incorrect use of the design rather than any inherent weakness? Had carrier-borne operations been envisaged earlier then I am sure the original Spitfire design would have incorporated a much stronger undercarriage, and a rear fuselage strong enough to absorb the arrester wire loading – both aspects had to be redesigned once it was clear that carrier operations had been added to the list of uses.

No doubt the narrower track made the aircraft more challenging for a pilot in any sort of crosswind than a Hurricane, but I’ve never before heard the Spitfire’s undercarriage arrangement being described as “weakness” … As has been said in earlier posts, mounting the undercarriage out-board would have needed a much stronger wing spar and structure, and possibly a thicker wing section overall to accomodate the landing load being applied further out along the wingspan – this may have made ground handling easier, but it would probably have compromised performance due to the thicker, heavier and less effficient wing that would have resulted.

Design optimisation is always about balancing various options to gain the “best” result within a set of “rules” or limitations, and about making the best compromises along the way – the Spitfire was designed to obtain maximum performance within a set of “rules” and using a particular engine, as was the Hurricane. Two outwardly similar designs (i.e. low wing, tail wheeled, monoplanes) resulted, but they were very different in many details. In short, two different solutions to the same set of design challenges were the result – your perceived “undercarriage weaknesses” in one may well have been avoided in the other, but then in other design aspects then maybe the situation was reversed. I would not like to argue that either was better or worse than the other.

Sorry, but I fail to see the Spitfire’s undercarriage as a particular “design weakness”, unlike say that of the Bf 109, which is known to have made that aircraft a real handful on the ground….

Paul F