SE5a vs. SPAD XIII

[cubsfan4life]

I recently purchased and am thoroughly enjoying the SE5a vs. Albatros book from Osprey, in which there is a quote from McCudden (i think) about how he felt the SE5A could out-dive any German fighter.
I am wondering if anyone has any data comparing the SE5a to the SPAD XIII, particularly the rate of dive and performance at high altitude. The research I have done so far points to the SE coming VERY close if not matching the SPAD, but looking for any other info to decide the case. Thank you in advance for any replies!!

[Chock]

Captain Frederick Selous, who was the leader of B flight in 60 Squadron, was killed when the wings came off his SE5a (serial number C5334). That happened in January 1918 when he was apparently diving onto a German two seater with full throttle. It has been estimated that his aircraft lost its wings at approximately 300 mph. That is a guess by people who witnessed it, but if it is anywhere near close, then it would put it in very similar territory to the SPAD, which could apparently dive at 280 mph.

The fact that Selous would try that seems to indicate he had a lot of (unfortunately misplaced) confidence in the SE5a, but for a craft such as that, it is an incredibly high speed and certainly way above what an Albatros could do. Both the SE5a and the SPAD were of course designed with fairly thin high speed aerofoils, which made both of them a bit of a pig at low speed by all accounts, the SE5 having to have its wings and ailerons modified a bit when it evolved into the SE5a. Some wing failures on the SE5a were the result of pilots pulling out of very steep dives at high speed too apparently, not too surprising really, since many pilots would be unaware of the way you can overstress things doing stuff like that.

Al

[Dan_San_Abbott]

Hi Chock:
The original prototype S.E.5 had a wingspan of 28 feet and raked wing tips. In order to improve the effectiveness of the aileron the span was reduced to 26'7 1/2". this modification improved the roll rate and reduced to yawing effect of the ailerons. The modified wings went into the production of the S.E.5. The third machine A'4563 with
The RFC Rigging Instructions define the S.E.5 with the 150 hp Hisso 8Aa and the S.E.5a with the 200hp Hisso 8Ba engine. It was the engines not the wing tips that was the difference between the S.E.5 and S.E.5a.
Blue skies Chock,
Dan-San

[Chock]

That's not the modification I was referring to Dan. It is true about the wing clipping on the prototypes, but the third prototype (A4563) was completed before the second prototype crashed (A4562), that crash revealing a fault which necessitated further modification after it was discovered (following a quite exhaustive investigation) that wing flexing and compression on the wing had caused a strut to detach causing the upper wing to collapse. The modification was to strengthen various bits, add better flying wires and put webbing on the ribs, which is what I meant when I said about 'evolving' into the SE5a. Ironically, Selous (who I mentioned having the 300mph crash) also flew A4562 (he brought it back to Farnborough in the UK from St Omer, where they'd made some 'combat' recommendations whilst assessing it), However, it was Goodden who was at the controls when it had that crash, the accident killing him as he put it through its paces over Farnborough.

The distinction between the SE5 and SE5a is not quite so simple however, since many SE5s were later brought up to SE5a standard by having a few modifications, sometimes having the undercarriage replaced and the engine switched out for the more powerful DD Hispano Suiza, which would then also sometimes mean the Foster Mount changed to the one without the packing that had been necessary to clear the geared Hispano's higher propeller arc. An example of that is actually SE5 A4563, which ended up serving in France with a few squadrons and was pretty much an SE5a as far as spec goes by the time it was struck off charge in Feb 1918, although it still had the old exhausts of an SE5. It was written off following a take off accident when serving with 84 Squadron. The legendary Cecil Lewis picked that one up from St Omer to fly it to 56 where it served a while, but at some point it went back to St Omer for repairs and ended up with 84 squadron. Quite a legendary aeroplane that one, for it shot down a few German aircraft too.

Al