Why was the SBD such an effective aircraft?

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Here's a faint negative taken during a training exercise over the Gulf of Mexico in 1944. That's the old man in #19. They had night trainings in these, as well, over illuminated die markers. The old man carrier-qualified on the "Speedy D" in 1944, June, off the Sable, in Lake Michigan, where they had to do 8 landings for that. Just a little more historical on these...

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Perdido Key, slightly west of Pensacola NAS had a target range on it during WW2. If you were lucky you could find inert practice bombs. I was never lucky.
 
On the F5F specs listed above it said 4 mins to 10,000' and 9+ to 20,000', which seems a little low for the weight and power. I am more inclined to agree with you. Are the above specs in error?

Perhaps a better supercharger, turbo's were a big hoopla to develop and manage. The Navy rejected the turbocharged F4U-3.

I dont think the specs on the test were in error. I figure if I reject specs from a test because I don't like them and only believe what I want to, then none of the tests on any aircraft would be valid.

The turbochargers has been developed in time, (P43 prototype the AP4 making 1200 hp was lost in March 1939) although the controls to work them weren't perfected until early 1942.

I agree that turbochargers were a bit of a pain compared to a regular engine, but if you compair it to a 2 speed 2 stage engine (depending on layout) it ditches the 2 speed supercharger for a simple 1 speed and still uses an intercooler. As far as extra maintenance goes, I would also like to point out that a turbocharged F5F is 20-60 mph faster than the original (depending on altitude). It's also easier to do maintenance on a turbocharged F5F that got back to the ship than it is to work on an F5F that got shot down because it wasn't turbocharged.

Think about in 1943 when the 1350 hp Cyclones came out. An F5F would have 2700 hp, if you used water injection it would have 2960 hp.
 
Pinsong wrote . This is true but it must be noted that 3 of the 4 penetrated to torpedo launch distance with no fighter cover. Had there been 20 B-26s with good torpedoes and well trained pilots, the Japanese fleet could have been severely attacked with 15 good and well targeted torpedoes.

I agree 100% with that. And what if those torpedoes could have been dropped at the B26's max SL speed as well....
 
Right you are. I was thinking (without checking) the XF5F was earlier than it was. Good catch!

So assuming it hadn't lost an engine, the F5F was probably fine for carriers, in fact with the enhanced visibility and lack of torque probably better than most. Assuming they improved the rudder a bit.
 
Actually the RAAF was quite happy with the vengeance and it's squadrons were doing good work up in New Guinea. The decision to withdraw the vengeance wing from combat came from USAAF orders, not RAAF. IIRC the RAAF leadership of these squadrons were not impressed...

Definitely not an expert, I was just going by what the Wiki said which sounds like there was people on both sides but that at least some of the Aussies thought they kind of got ripped off by being given them. It doesn't seem like too bad of a plane to me but it's just another matter of it being more of a 1942 plane being used in 1943 and 44. Probably pretty vulnerable to Zeroes and Oscars?
 
Some of these examples are not correct.
The P-40 was a P-36 with a new engine (of course the P-36/Hawk 75 had already gone through 4 or 5 engines)

The P-40 was derived from the P-36, per Don Berlin, as I have quoted on this forum before.

and yes the P-51B was derived from the Allison P-51.
However some of the others like the Hurricane/Fury and and the F4F/F6F had nothing more in common than being made by the same company.
I qualified the mention of the F6F / F4F anticipating just such an attempted 'gotcha', though I gather some parts were shared, it's debatable. I wrote: "was at least partly derived from the F4F. Or was it? I'm not sure about that one. " But you act like I made a definitive statement.

Tales of the Fury monoplane notwithstanding. There was a fury monoplane on paper, it was tossed and the Hurricane was a fresh start.

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From the wiki:

Sidney Camm designed a monoplane version of the Fury in 1933. It was not developed until Rolls-Royce produced what became their famous Merlin engine. The design was then revised according to Air Ministry specification F5/34 to become the prototype Hawker Hurricane.

So clearly there was a lineage. Of course the Hurri was a new design however it did share certain features, look at the tail, the cloth covered rear fuselage (and other cloth covered parts on early Hurris). This is why the Hurricane was more of an incremental step from the earlier Fury series, and thus available in a reliable format quite early, compared to say the Spitfire.

The I-153 first flew about 3 1/2 to 4 years after the I-16. The I-16 used a wooden fuselage and metal wings (at least the structure) while the I-153 use a metal fuselage and fabric covered wooden wings.

This is extremely disingenuous. My post: "the I-16 was a monoplane version of the I-15 / 153" - yes the I-153 was a further development of the I-15 as a biplane, and yes Chimpanzees are a further evolution of the primate as a great ape, but both came from a common lineage, in this case the I-5


Looks like an obvious family resemblance to me. Fuselage shape, tail, landing gear, cockpit. F4F was derived from an incremental update of the F3F called the G-16 in internal company nomenclature and XF4F-1 to the Navy, then redesigned a couple of times, first as a monoplane in the XF4F-2, to the XF4F-3 standard. A bit step forward, but still incremental changes, with a clear design lineage to the F3F. With many shared parts and tooling.
 
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So assuming it hadn't lost an engine, the F5F was probably fine for carriers, in fact with the enhanced visibility and lack of torque probably better than most. Assuming they improved the rudder a bit.

I think with both engines working the F5F would have been fantastic to land on a carrier. As you said, you can see and there is no torque since the engines cancel each other out. I'm sure you've read about how a P38 could get down to 100 mph and turn inside a lot of single engine planes by just hanging on the props, that is what I picture the F5F being able to do. I picture it in my head coming in, flaps down, just hanging on the props right above stall, rudders still working fine since they are sitting directly behind each engine, you can see the Landing officer just fine, and if you do get a wave off you can slam the throttles forward and go just go straight and up with out having to worry about torque rolling into the water upside down. For what its worth it sure sounds good while I'm sitting at home behind a computer.....
 
I think with both engines working the F5F would have been fantastic to land on a carrier. As you said, you can see and there is no torque since the engines cancel each other out. I'm sure you've read about how a P38 could get down to 100 mph and turn inside a lot of single engine planes by just hanging on the props, that is what I picture the F5F being able to do. I picture it in my head coming in, flaps down, just hanging on the props right above stall, rudders still working fine since they are sitting directly behind each engine, you can see the Landing officer just fine, and if you do get a wave off you can slam the throttles forward and go just go straight and up with out having to worry about torque rolling into the water upside down. For what its worth it sure sounds good while I'm sitting at home behind a computer.....

The F5F seems to have had a lower wing loading than a TBF or a F6F so normal landing should have been fine.

Landing on a carrier with one engine is no doubt, not fun. What did they do with say an E2 hawkeye or C-2 greyhound if one engine went out? Ditch or land?

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If you still have the one engine and have made it through takeoff you can probably get the pilot back to the vicinity of the carrier and the pilot is really the most valuable thing, at least that is how it seems to have turned out in WW2 right? I would say engine reliability being so important for Navy / Carrier planes might be a reason for not putting turbos in prior to say late 1942.
 
That's not the speed that matters. Vmc, or Velocity minimum controllable is the speed below which there isn't enough rudder authority to keep the plane from yawing and rolling into the dead engine with the working engine at full power.

This is an indication of a rudder authority problem, which seems to be confirmed by the small size of the tailfeathers. This implies that Vmc might be rather high and likewise single engine landing speed. The TBF was still several years in the future, so this would likely be the heaviest and fastest and by far the highest energy the arresting gear had ever had to cope with.
Cheers,
Wes

Quick question: Rudder force is the amount of pressure it takes for the pilot to apply a certain degree of rudder correct? In this case, the rudders are directly behind each engine. Would high rudder forces indicate that the rudder is being effective because the wind/prop wash is pushing back against the pilot? Would high rudder forces be more indicative of the gearing/ratio of the rudder pedals to the rudder? It seems to me if a rudder pedal was super easy to move then that would mean there is no resistance at the rudder i.e. no airflow pushing back. The P36 would easily out roll an early Spitfire because the P36 ailerons were geared lower so the P36 pilot had to move the stick farther for a given deflection of the ailerons but it was easier to move and could be done at high speed where the Spitfire ailerons or the Zero's were immovable.

I know your a pilot and mechanic, am I looking at this wrong?
 
The F5F seems to have had a lower wing loading than a TBF or a F6F so normal landing should have been fine.

Landing on a carrier with one engine is no doubt, not fun. What did they do with say an E2 hawkeye or C-2 greyhound if one engine went out? Ditch or land?

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If you still have the one engine and have made it through takeoff you can probably get the pilot back to the vicinity of the carrier and the pilot is really the most valuable thing, at least that is how it seems to have turned out in WW2 right? I would say engine reliability being so important for Navy / Carrier planes might be a reason for not putting turbos in prior to say late 1942.

I would agree with getting pilot back to fleet even if he had to bail out or ditch is the most important thing. I also agree that turbochargers weren't very reliable pre 1942 and that, plus weight, plus increased maintenance all make sense on why they didn't do it. Plus, turbochargers were relatively new and maybe they didn't understand how much they would increase performance. They also, I believe, seriously underestimated what the Japanese were capable of. No one really understood what carrier warfare was going to be like or what they were capable of doing.

Hindsight is a big help to making decisions. In hindsight I would have bought $10,000 of bitcoin in 2008 or so for .001 a piece, sold it all for $19,000 a piece and had someone build me an F5F and an aircraft carrier so I could show you guys how good it was......but that is hindsight
 
I would agree with getting pilot back to fleet even if he had to bail out or ditch is the most important thing. I also agree that turbochargers weren't very reliable pre 1942 and that, plus weight, plus increased maintenance all make sense on why they didn't do it. Plus, turbochargers were relatively new and maybe they didn't understand how much they would increase performance. They also, I believe, seriously underestimated what the Japanese were capable of. No one really understood what carrier warfare was going to be like or what they were capable of doing.

Hindsight is a big help to making decisions. In hindsight I would have bought $10,000 of bitcoin in 2008 or so for .001 a piece, sold it all for $19,000 a piece and had someone build me an F5F and an aircraft carrier so I could show you guys how good it was......but that is hindsight

Indeed. Captain Hindsight is the most powerful superhero. I think they did know the potential of the turbo that is why they pushed at it so hard, but it seemed to take a really long time to get it right anyway, and I think maybe some exotic materials? Did early turbo impellers require special alloys? The other thing is that the US WW2 turbochargers seemed to be not just heavy but also very big. Wasn't the one on the P-47 almost the size of a washing machine?

Turbo vs. supercharger seems to be one of those things that exemplifies proven vs. new technologies and their relative merits and flaws. Water injection + supercharger may be a bit more limited but probably far more reliable for carrier use. Turbo is what you really need if you intend to fly at very high atlitudes but the Japanese never really mastered high flying. Of course, we know that now. Even some of the superstar planes of WW2 didn't always look that way at the time. I remember reading a pilots description of all the frustrating maintenance hassles of the early F4U, which made it sound like a real nightmare. But put it all together and, when it was working, it was causing serious problems for the enemy.
 
I qualified the mention of the F6F / F4F anticipating just such an attempted 'gotcha', though I gather some parts were shared, it's debatable. I wrote: "was at least partly derived from the F4F. Or was it? I'm not sure about that one. " But you act like I made a definitive statement.
I got what you were saying. At any rate, funny they're both from the same manufacturer, they both look somewhat similar, and yet, for the most part, they're so different. Contrast that with the FM and F4, from different manufacturers, and yet, for the most part, they're virtually indistinguishable.
 
Clearly F4 to F6 is a big step, regardless of any continuity. But it's not as radical a departure as say, the Corsair or the Tigercat.

aren't FM and F4 basically the same design? I gather FM2 was considered a lot better but I never grasped why. Was it more like the F4F-3? Better engine?

I saw one (an FM2) doing loops and stall turns at an airshow last year and it was really quite impressive. The pilot-owner seemed to be genuinely nuts, he did some high speed pull-outs at ~ 30 feet. I heard the airshow people muttering about it. Maybe he was trying to prove a point? If so he succeeded with me. The fighter was decidedly more acrobatic than I was expecting. It wasn't as fast as the Corsair or the Yak or the P-40, but it was definitely agile and quick, and seemed to have plenty of power for climbing

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If the Zero and the Hayabusa were really much more agile than that then I would really like to see one of those put through it's paces one day.
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aren't FM and F4 basically the same design?
Yes. Grumman was getting busy with something else at the time (;)), that's why they let it go. The F4/FM still had a lot of utility. My Dad did a stint towing targets in the FM.
 
Quick question: Rudder force is the amount of pressure it takes for the pilot to apply a certain degree of rudder correct? In this case, the rudders are directly behind each engine. Would high rudder forces indicate that the rudder is being effective because the wind/prop wash is pushing back against the pilot? Would high rudder forces be more indicative of the gearing/ratio of the rudder pedals to the rudder? It seems to me if a rudder pedal was super easy to move then that would mean there is no resistance at the rudder i.e. no airflow pushing back. The P36 would easily out roll an early Spitfire because the P36 ailerons were geared lower so the P36 pilot had to move the stick farther for a given deflection of the ailerons but it was easier to move and could be done at high speed where the Spitfire ailerons or the Zero's were immovable.

I know your a pilot and mechanic, am I looking at this wrong?
Actually rudder force is the amount of force it takes to achieve the desired response, which is not the same as achieving a specified number of degrees of deflection. It's a dynamic rather than a static thing.
Having the stabilizer/rudder directly in the propwash is a two edged sword. It helps by making rudder effectiveness more proportional to engine power, and hence to thrust asymmetry, and it can hurt by making rudder forces very high at high power settings if not very carefully designed. Designers new to multi engine design, especially in the early days of twin engine monoplanes, sometimes took awhile to sort out the nuances. Look at the plethora of twin tail designs of the 30s and 40s. Even down to the miniscule Ercoupe! Two rules of thumb seemed to prevail: "2 tails are better than 1", and "size matters; bigger is better". Compare the XF5F with its vestigial tailfeathers and its heavy rudder forces and the B25 with its large double tail and its legendary single engine handling.
A larger rudder/stabilizer combo requires less deflection to achieve the same result because of surface area and Reynolds number. The less deflection allows better mechanical advantage between rudder pedal and control surface. Witness shot up B17s, with only one outboard engine running, drifting slowly downward, held straight by an UNBOOSTED rudder and two exhausted pilots as they put miles behind them from the target area and hoped for the Channel.
Hope that answers your questions.
Cheers,
Wes
 

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