Improve That Design: How Aircraft Could Have Been Made Better (1 Viewer)

[Shortround6]

Let's improve these RAF Lend Lease failures....

Vultee Vanguard

Why???

The Vanguard was an attempt to get more sales from trainer airframe (lower cost of tooling).
It broke a lot in service.

You can fix anything with enough time and money.
Question is if the time and money is better spent elsewhere.

The RAF never ordered it.
It was offered to them for free when they could not deliver the planes to Sweden.
The RAF took them to use as trainers (they didn't want them for combat even in the months after the BoB)

There is more to the story but unless you change quite a bit you are putting lipstick on a pig.

Vought Chesapeake

Again, why?
It was underpowered. Unless you can fix the power problem it doesn't matter what else you do with it.
Yes Vought had built a prototype with a P&W R-1830 engine. There were no takers.
The Chesapeake, as built was not used to dive at over 60 degrees.

You want a better dive bomber than the Skua?

Put a better engine on the Skua, increase gross weight

BUILD BETTER BOMBS!!!

 

[XBe02Drvr]

The design was kept relatively compact (41 foot wingspan) and the wings were designed for strength, so folding was not an option because of that.

A folding wing SBD would have required a Grumman style fold for height reasons, as well as a thicker (for strength) airfoil, making it an overweight, slow, TBD clone. Ed Heineman found the sweet spot to put it all together. Don't butcher success.

And the Helldiver? Scuttle it and the Curtiss it rode in on, and put Ed to work on the Skyraider early. Meanwhile, up-engine the SBD with the higher powered version of the R1820. I think they eventually got up to ~1475 HP.

 

[Shortround6]

Meanwhile, up-engine the SBD with the higher powered version of the R1820. I think they eventually got up to ~1475 HP.

They did but not in WW II unless the last few months?

The SBD went through 3 major engine changes (not counting a carburetor or magneto change) and they were major changes.

The SBD-1/4 used a 1000hp engine.
The SBD-5 used a 1200hp engine.
The SBD-6 used a 1300-1350hp engine.

The engine used in the SBD-5 was similar to the engine used in the F2A-3 and in the later Mohawks and the basic engine used in the B-17 and other aircraft.
The engine used in the SBD-1/4 was an R-1829-52 and used a different crankcase, different crankshaft, different cylinder barrels and different cylinder heads. in other words it was built on older tooling.
The engines used in the SBD-6 was another major change with once again, different everything and the 1300hp and 1350 hp versions used a different crankshaft although I don't know if you could swap the new crankshaft into the existing engine.

The 1425hp versions weren't shipped until 10/45.

 

[EwenS]

The Vought Chesapeake was an inheritance from a French contract taken over immediately prior to the French surrender in June 1940. Having got 50 of them in early 1941 the question was what to do with them. 811 squadron FAA formed on them in July 1941 and was intended to go aboard one of the escort carriers then building in the USA. They quickly found that its take off run would be too long for those ships so the squadron swapped to Swordfish in Nov 1941. Eric Brown wrote that some of its problems stemmed from British efforts "to render it a 'fully operational' aeroplane".


Britain never intended to acquire the SBD as a front line aircraft so the question of needing to modify it for use from British carriers never arose. It only acquired 9 SBD-5 in late 1943 / early 1944 for trials purposes. Deliveries were divided between the RN and RAF. RN interest was in the bomb sight it was fitted with, as that was also to be fitted to the Curtiss SBW Helldivers that it was about to receive. The RAF was interested in comparative trials against the Vultee Vengeance.

Britain did order 450 SBW Helldivers from the Canadian Car & Foundry production line. But such were the delays in the Helldiver programme it only ever received 26 late 1943 / early 1944. Only one squadron was formed on them. Its history is here:-

1820 Naval Air Squadron

www.royalnavyresearcharchive.org.uk

Perhaps the best way of putting its problems is to quote Eric Brown who test flew it in Oct 1944:-
"...the handling characteristics of the 'Beast' were such that it would never have been allowed near a British carrier deck!"

He concluded:-
"....Quite frankly, with the terrible aileron control at approach speed and the excessive longitudinal trim change with engine power, the Helldiver would never have been acceptable for deck landing by British standards, and, indeed was never flown onto a British carrier by an FAA pilot."

That last statement isn't entirely true as a detachment from 1820 squadron spent 2 days aboard the escort carrier Speaker for deck landing training at the end of Oct 1944 before returning to a shore base and disbanding in mid-Dec 1944.

The other problem with it is one of physical size when folded. Folded width 22'6", folded height 16'10". So they don't fit either an Illustrious or Implacable class carrier as they are too tall. Even if you chop a bit off the wings like the Corsair (which would have probably made the handling around the deck worse) you are only going to be able to fit them two abreast in the hangar, compared to three abreast for the Barracuda and Avenger.

By the time that the Helldiver was rolling of Canadian production lines in July/Aug 1943, the RN had a dive bomber in service with increasing numbers coming off 3 British production lines. While the Fairey Barracuda May not have been the best dive and/ or torpedo bomber of WW2, it handled very well around the flight deck and in particular being easy to land.

So really the Helldiver had nothing to commend it to the RN.

 

[GrauGeist]

Given its success and robustness I can't fault its designers. It is noteworthy that Dauntless and Aichi D3A aside (granted, the two most important and successful naval DBs of the war) the other naval dive bombers, including the Skua, Loire-Nieuport LN.401, Vought SB2U, Curtiss SB2C, Stuka (prototype), Yokosuka D4Y and Aichi B7A had folding wings.

The one attribute the SBD had over the others listed, was it's ability to enter a near 80° dive with absolute rock-solid stability, which in turn, enhanced it's accuracy.

 

[Shortround6]

Eric Brown wrote that some of its problems stemmed from British efforts "to render it a 'fully operational' aeroplane".

Since they never changed the engine from the 825hp R-1535 engine and they did try to add machine guns and protected tanks(?) and crew protection (?) we can see where this was going to go.

I would note that while max fuel may have been 310 gallons (unprotected tanks) that would have been with no bomb.

If anybody has not downloaded this manual yet

upload pilots handbook for sbd-3 dauntless

Hi All, uploaded pilots handbook for sbd-3 dauntless cheers Jerry

ww2aircraft.net

For the SBD I would strongly advise it as it has weights and capacities for both protected and unprotected versions and performance charts/tables.
It is also at an early gross weight and would be more comparable to other early war aircraft.

I would also note that Vought's original idea was to use a fully feathering or reversible pitch propeller as an air brake for diving.
This did not work out in practice and most (all?) of the SB2Us tried to use lowering the landing gear as a substitute.

Going back to the SBD-3, the dive brakes could be extended at any speed less that the max level speed of the airplane.
However the landing flaps were not to lowered at speeds over 140kts. Neither was the landing gear supposed to lowered at speeds over 140kts.

Not saying that the SB2U couldn't lower it's landing gear at higher speeds. Just saying that if you are going to change things sometimes more stuff needs to be changed that it first appears.

 

[MiTasol]

A folding wing SBD would have required a Grumman style fold for height reasons, as well as a thicker (for strength) airfoil, making it an overweight, slow, TBD clone. Ed Heineman found the sweet spot to put it all together. Don't butcher success.

And the Helldiver? Scuttle it and the Curtiss it rode in on, and put Ed to work on the Skyraider early. Meanwhile, up-engine the SBD with the higher powered version of the R1820. I think they eventually got up to ~1475 HP.

Or they could just fold the tips like on the A6M - and have the absolute minimum weight penalty to go with it

 

[ThomasP]

The French model of the SB2U (the V-156-F) had wing fence dive brakes in service, and did not lower the landing gear when diving. From what I have read the French considered the V-156-F quite effective.

The R-1830 powered version was intended for sale to the French.

 

[XBe02Drvr]

Or they could just fold the tips like on the A6M - and have the absolute minimum weight penalty to go with it

Would that reduce span enough to make the SBD viable for the RN?

 

[wuzak]

Some developments that could have helped the Spitfire was to get multiple position flaps and radiator outlets, each of which was only 2 positions on the Spitfire.

Multiple position flaps may have allowed shorter take-offs by enabling partial flaps to be selected. As it was they were either up or down. It also would have helped Seafires.

Multiple position output flaps for the radiators could have improved radiator efficiency by getting the correct amount of cooling, instead of too much or too little.

Smith also, apparently, admitted that that the areas for the inlet and outlet of the radiator duct were incorrectly sized. IIRC, he thought the inlet was too large.

 

[EwenS]

Would that reduce span enough to make the SBD viable for the RN?

The complication with the SBD is that the ailerons extend to the wingtips and would have to be split. Presumably they can't be reduced in size.

Illustrious class lift size was 45x22ft. The forward lift only in Indomitable and the Implacables increased to 45x33ft.

 

[XBe02Drvr]

The complication with the SBD is that the ailerons extend to the wingtips and would have to be split. Presumably they can't be reduced in size.

That's why the wing fold would have to be at the center section/wing panel junction, making a conventional fold too tall and a Grumman-style fold necessary. A Grumman fold is troublesome on a wing as thin as the SBD's for strength reasons, probably requiring a redesigned thicker (and draggier) wing.

 

[ThomasP]

SBD wing airfoil was the NACA 2415 root to 2409 tip, with a chord of 115" at the join of the inner/outer wing sections. The F4F/F6F/TBF were all NACA 23015 root to 23009 tip. SBD has same T/C ratio as the airframes with the Grumman STO wing fold - so should be enough room in terms of wing thickness.

From SBD-2 Erection & Maintenance manual:

 

[EwenS]

That's why the wing fold would have to be at the center section/wing panel junction, making a conventional fold too tall and a Grumman-style fold necessary. A Grumman fold is troublesome on a wing as thin as the SBD's for strength reasons, probably requiring a redesigned thicker (and draggier) wing.

And then you run into the height constraints on British carriers. Not the 17'6" height of the then modern US ships (earlier ones had more) but 16' on pre-war and Illustrious class and 14' in the upper hangar of Indomitable and both hangars in the Implacables.

 

[MiTasol]

Would that reduce span enough to make the SBD viable for the RN?

Depends on where they made the fold. Certainly worked on the Spitfire though the aileron issue may have been a killer.

 

[GrauGeist]

I imagine that if they redesigned the SBD's wing to fold (in any configuration), it would affect it's dive angle for the reason that once those massive dive brakes deploy, that would put considerable stress on the joints.

 

[Reluctant Poster]

Totally agree, especially in Japan's case. They did misinterpret a lot and completely underestimate how the United States would react, to their detriment.

What strikes me as interesting about this whole debate regarding the Japanese philosophy of manoeuvrability and little self protection for their aeroplanes is that we, the observers so many years later apply what we know and can only know in hindsight to argue that the Japanese were somehow stupid for doing so. The reality was that everyone was doing what the Japanese were doing, even the Americans. The P-36 was a decent dogfighter (that doesn't get nearly enough attention - I might be biased, I think it's cooler even than the P-40) and could out-manoeuvre the Spitfire and Hurricane, which in themselves were good dogfighters, which proves that manoeuvrability was definitely a virtue in fighters of the late 1930s vintage.

The Japanese took it to extremes in the A6M, of course, but we are so ingrained with that aircraft's history that we believe that it was the be-all and end-all of Japanese design philosophy, but it wasn't. No other fighter the Japanese built was just like the Zero - except other Zeroes of course. Even Horikoshi's subsequent designs eschewed the Zero's advantages for those things we think the Japanese ignored. Yes, the philosophy of the Ki-43 was the same as the A6M, but it wasn't achieved at the same expenses as the A6M. Its design was based on limited engine power, like the Zero, but we simply don't acknowledge that changes in fighter philosophy, like heavy armament, boom and zoom manoeuvres, armour plate and self-sealing tanks came as a result of experience with enemy aircraft, not strictly beforehand.

Combat in Europe, as I mentioned earlier illustrated the need for self-sealing tanks, armour plating and heavier armament, but as mentioned, these took time to implement. There were still Bf 109s in frontline service with only four machine gun-calibre weapons in the spring/summer of 1940. The RAF had frontline fighters with eight guns, more than anyone else's fighters at the time, but they still weren't heavy hitting enough and first contact with the enemy in late 1939 proved that the pilots still had to empty their magazines just to bring down a single Heinkel. Spitfires and Hurricanes didn't get heavy cannon as standard until after the Germans. The A6M had cannon as standard, ironically.

So, to conclude, what we were doing was little different to what the Japanese were doing. They took it quite far with the A6M, but it was not the norm. We like to think that these advantages our fighters had were a given because we've come to accept that, but in the first year to two years of WW2, they simply weren't.

The primary requirement that dictated no self-sealing fuel tanks was to achieve the fantastic range that no fighter aircraft of the era could remotely duplicate. The Japanese Navy was the only air force in the world that realized the need for long range escort of bomber and actually solved the problem.

 

[drgondog]

The primary requirement that dictated no self-sealing fuel tanks was to achieve the fantastic range that no fighter aircraft of the era could remotely duplicate. The Japanese Navy was the only air force in the world that realized the need for long range escort of bomber and actually solved the problem.

Actually, AAC/AAF recognized the Need, just failed to elicit proper RFP out of Materiel Command before WWII engulfed US. Arnold was well aware that day fighters dominated bombers in Spanish Civil War and BoB. Others in chain of command, particularly Spaatz were of the opinon that high altitude performance of B-17 would reduce attrition sufficiently to achieve strategic objectives as we began deployment of 8th AF to UK.

Additional Factors seperating IJN from AAC was bombing doctrine and platforms. There was no need for Japan to produce long range escort fighters with high altitude performance

The A6M would not have been a great escort for 8th AF in ETO.

 

[GrauGeist]

The A6M (and KI-43) had long range because of the distances involved in patrolling and expanding the Empire.

That they could escort their bombers over long distances was a bonus to their primary mission.

 

[Reluctant Poster]

Actually, AAC/AAF recognized the Need, just failed to elicit proper RFP out of Materiel Command before WWII engulfed US. Arnold was well aware that day fighters dominated bombers in Spanish Civil War and BoB. Others in chain of command, particularly Spaatz were of the opinon that high altitude performance of B-17 would reduce attrition sufficiently to achieve strategic objectives as we began deployment of 8th AF to UK.

Additional Factors seperating IJN from AAC was bombing doctrine and platforms. There was no need for Japan to produce long range escort fighters with high altitude performance

The A6M would not have been a great escort for 8th AF in ETO.

Thats why I added the statement "and actually solved the problem". Certainly long range escort at high altitude was a much more difficult problem given the limitations of the engines available in 1940