Recurring Theme in WW2 Aviation

[Robert Porter]

I read, a LOT, and I have read probably 200+ books dedicated to WW2 aircraft. I also read about modern aircraft. And I have noticed over the years a constant refrain. Without any exception I can find every aircraft ever delivered during WW2 was initially underpowered or had no Super or Turbo chargers and therefor was restricted to lower level performance envelopes.

And it does not matter the year they were first delivered from 1938 all the way up to and including 1945. Now I expect bugs, design tweaks based on usage and testing. But underpowered? No. So why? In every case better engines were already available, costs were in many cases comparable, and by 1940 we already knew we needed 2 stage Supercharges to preserve performance at altitude.

Yet over and over again aircraft were delivered with underperforming engines, including all the favorites, the Mustang, Hellcat, Spitfire, you name it. Reading first hand accounts from the pilots that tested these aircraft read like boiler plate. Great maneuverability, great handling, no power, no legs at altitude. Ad nausea.

I like to think designers are competent people but what was wrong with these idiots all through the war and constantly delivering underpowered aircraft?

Heck a step grandfather I had was a carrier pilot in the pacific and mentioned case after case of aircraft being "beached" until better more powerful engines arrived. The F4U was a classic example, it took the British to figure out how to land the thing on a carrier. And it took a year for better engines to catch up with it.

 

[tomo pauk]

Pilots (and not only them) alyways wanted more power/thrust, that's the trend that continues in 21st century. As for supercharging - every, that is every military aircraft was outfitted with a supercharged engine in ww2, bar some entry-level trainers. Yes, even the vast majority of transport aircraft have has superchargers on their engines.
The Hurricane, as delivered in 1938, was certainly not underpowered, nor it was the case with Spitfire or Bf 109 or Fw 190. Those flew and fought above 20000 ft if needed. That cannot conceal the fact that some of them were better than some others at hgh altitudes, no aircraft and their engines were created equal.
Problem with 2-stage supercharged engines, and that includes turbocharged ones where turbocharger is the 1st of 2 compressor stages, took some time to refine and make suitable for military aircraft installation and usage. Eg. Soviets were just behind the Americans when it is about turbochaged engines in late 1930s, yet they never fielded a miltary aircraft with such an engine. Junkers experimented with 2- and even 3-stage S/C in 1930s, yet it took them until late 1944/early 1945 to have the 2-stage supercharged engine in production. The turbocharged BMW 801J was produced a bit earlier, it employed the air cooled turbine blades allowing for a compact installation.
American fighter aircraft have had another problem or two. USAAC/USAAF aircraft were with bigger fuel load and guns/ammo load than most of European or Japanese counterparts, they were with big enough wings so they are safe to fly and easier to land and take off, so both drag and weight will easily go up. US standards on G limit were highest on the world = more weight. More protection than on Japanese aircraft = more wegith. Installing the Russian or Japanese engine on American naval fighter will barely lift it from the runaway, to make a hyperbole.

 

[aurora-7]

While 'underpowered' was a common issue with new aircraft I never came away with the breadth of history I've read that it was consistent on all aircraft. For example, I've never heard of the Spitfire as being referred to as underpowered on delivery.

And for the Corsair and being carrier qualified, I heard it wasn't engine power but the problem with the Oleo struts causing too much bounce on landings. The Royal Navy just took it as it was because they didn't consider it as much as an issue.

 

[Robert Porter]

While 'underpowered' was a common issue with new aircraft I never came away with the breadth of history I've read that it was consistent on all aircraft. For example, I've never heard of the Spitfire as being referred to as underpowered on delivery.

And for the Corsair and being carrier qualified, I heard it wasn't engine power but the problem with the Oleo struts causing too much bounce on landings. The Royal Navy just took it as it was because they didn't consider it as much as an issue.

Yes the primary issue with Corsair was the struts and lack of forward visibility. However the Navy also complained about lack of power for fully loaded carrier takeoffs. This was addressed later. The landing by approaching in a wide sweeping turn lining up at the last second. The takeoff at full weight by an improved engine and turbo design.

 

[Robert Porter]

While 'underpowered' was a common issue with new aircraft I never came away with the breadth of history I've read that it was consistent on all aircraft. For example, I've never heard of the Spitfire as being referred to as underpowered on delivery.

And for the Corsair and being carrier qualified, I heard it wasn't engine power but the problem with the Oleo struts causing too much bounce on landings. The Royal Navy just took it as it was because they didn't consider it as much as an issue.

As for the Spitfire it initially suffered from a poor climb rate. From Mk1 to Mk2 A 3 bladed prop was added as well as the engine being upgraded from a Merlin Mark II to III which was shortly again replaced with a Mark XII engine. Both engine replacements and the initial change from wood 2 bladed to metal 3 bladed propellor increased climb performance significantly. And these changes had been anticipated by its primary designer Mitchell who died of cancer in 1937. Yet the Mark 1 was delivered with neither change.

As I say an recurring theme...

 

[fastmongrel]

When the Spitfire and Hurricane Is came into service they had the most powerful engine available the 1030hp Merlin III. It wasnt till late 1938 that the Bf109E caught up with the 1060hp DB601A.

The FAA clipped the Corsairs wingtips to fit in the lower RN hangers and this partly helped with the sinkrate on landing. The FAA also altered the valves in the Oleos to make the compression softer and the rebound slower. These changes with the FAA use of a curved approach to the carrier helped make things safer but never exactly safe.

 

[rednev]

As for the Spitfire it initially suffered from a poor climb rate. From Mk1 to Mk2 A 3 bladed prop was added as well as the engine being upgraded from a Merlin Mark II to III which was shortly again replaced with a Mark XII engine. Both engine replacements and the initial change from wood 2 bladed to metal 3 bladed propellor increased climb performance significantly. And these changes had been anticipated by its primary designer Mitchell who died of cancer in 1937. Yet the Mark 1 was delivered with neither change.

As I say an recurring theme...

 

[Robert Porter]

And please don't read anything into my post, it was mostly in the form of typical government contractor behavior. Perhaps even rhetorical. I certainly don't think it was anything nefarious. Just struck me again as I was reading a book about the Hellcat development how often developers settled for a poorly performing engine when better were readily available. I know that sometimes there were production issues that constrained an engine choice simply due to not enough of a type being available.

 

[rednev]

There is quite a long time between drawing board and entry into service .
do you design around current engine designs or around expected egines ......lets not say sabre

 

[BiffF15]

Rob Porter,

Recurring theme, well maybe there is another way to look at it.

I think it was true then as is now, and that would be the quest for more power. Look at the Spit, Mustang, Fw-190, Bf-109, F-15, F-16, F-18. All were launched with a "given" engine and later upgraded. Also remember that the upgraded engines are for improved excess power (advantage over earlier version as well as over what the enemy has currently fielded) & improved performance (to include a heavier aircraft via production changes or combat load out) as well as improved reliability. You can say the early models were underpowered, but would think that the airframes were aerodynamic stretches to current technology as were the engines. Everybody was working their collective buttocal areas off (airframe & engines), and incremental changes were to follow.

Cheers,
Biff

 

[tomo pauk]

Yes the primary issue with Corsair was the struts and lack of forward visibility. However the Navy also complained about lack of power for fully loaded carrier takeoffs. This was addressed later. The landing by approaching in a wide sweeping turn lining up at the last second. The takeoff at full weight by an improved engine and turbo design.

There was no such thing as 'turbo design'.
Corsair have had the most powerful engine available in the USA (and then some), the 2-stage supercharged R-2800. I don't believe that Navy ever complained about the lack of engine power, even is it is a bomb-laden Corsair from the CV.

As for the Spitfire it initially suffered from a poor climb rate. From Mk1 to Mk2 A 3 bladed prop was added as well as the engine being upgraded from a Merlin Mark II to III which was shortly again replaced with a Mark XII engine. Both engine replacements and the initial change from wood 2 bladed to metal 3 bladed propellor increased climb performance significantly. And these changes had been anticipated by its primary designer Mitchell who died of cancer in 1937. Yet the Mark 1 was delivered with neither change.

As I say an recurring theme...

Spitfire's climb rate was on par with anything and much better than majority of fighters from any choosen year. Period. I'm not sure how someone is supposed to install the Merlin XII from 1940 into the Spitfire of 1938 either. Mitchell anticipated the wooden, 2-bladed prop on Spitfire.

Robert - stick around. Take time to read some posts that deal with techincal matter, don't feel that someone will patronize you.

 

[wuzak]

As for the Spitfire it initially suffered from a poor climb rate. From Mk1 to Mk2 A 3 bladed prop was added as well as the engine being upgraded from a Merlin Mark II to III which was shortly again replaced with a Mark XII engine. Both engine replacements and the initial change from wood 2 bladed to metal 3 bladed propellor increased climb performance significantly. And these changes had been anticipated by its primary designer Mitchell who died of cancer in 1937. Yet the Mark 1 was delivered with neither change.

As I say an recurring theme...

Performance improved from the 2 or 3 blade 2 position props to the 3 blade constant speed props because of the props, not because of additional power.

They weren't incorporated earlier because they weren't available earlier.

Also, I don't think pilots thought the Spitfire XIV, or even the XII, were underpowered.

 

[wuzak]

And it was very possible to over-power an airframe.

 

[pbehn]

As a former motorcycle racer my bike had great power until I came across someone with a bike that had a better tune, in the spring of 1982 with my newly tuned RD 250LC I swept all before me winning three races with monotonous ease at Snetterton.....being underpowered was just a comparison to the opposition. The Spitfire had a lower swep volume than the Me109 but had access to better fuel, throughought the war the pair competed for top dog spot....i is still debated as to which one made it.

 

[Shortround6]

And please don't read anything into my post, it was mostly in the form of typical government contractor behavior. Perhaps even rhetorical. I certainly don't think it was anything nefarious. Just struck me again as I was reading a book about the Hellcat development how often developers settled for a poorly performing engine when better were readily available. I know that sometimes there were production issues that constrained an engine choice simply due to not enough of a type being available.

Most fighters were designed around the biggest, most powerful engine either in existence or likely to be available when the plane went into production, often 2-3 years from pencil being put to paper.
In the case of the US the only engine bigger (and likely to be built) than the R-2800 in 1940-42 was the Wright R-3350 and that had more than few problems of it's own. It was also bigger in diameter and weighed as much as the R-2800 except it had a single stage supercharger compared to the R-2800s two stage. Performance at altitude without turbo was not good.
Version/s used in B-29 were a complete re-design from the 1940-42 version and gained around 200lbs in weight.
For the Hellcat the only poorly performing engine was the R-2600 installed in one prototype for a short period of time. Of course with a 12,000lb fighter (clean) even 2000hp is a bit low
Adding bombs/drop tanks could push the weight up by another ton or more. The Bombs/drop tanks may not have been part of the original specification. Hellcats got water injected engines not long after they became available and planes in the field were often retro-fitted.
As has been noted by others the US tended to go a bit overboard in specifying guns and ammo. Few other fighters in the world carried the weight of guns and ammo that US fighters did. A Hellcat carried over 1150lbs of guns and ammo, this does not include mounts, gun heaters, charging systems, ammo bins/chutes,etc.

Early US fighters suffered from being designed before armor and self-sealing tanks became standard. This added 400lbs or more to such planes as the F4F, F2A, P-39 and P-40. Uprated engines didn't always show up in time to handle the weight increase which was not helped by the Army and Navy increasing the number of guns and/or ammo carried. Pre-war planning for the Navy included yanking two of the .50 cal guns when the F2A and F4F carried even a pair of 100lb bombs. Something that never happened in service.
Blaming the companies that built the aircraft or engines doesn't seem quite fair.

 

[Robert Porter]

Most fighters were designed around the biggest, most powerful engine either in existence or likely to be available when the plane went into production, often 2-3 years from pencil being put to paper.
In the case of the US the only engine bigger (and likely to be built) than the R-2800 in 1940-42 was the Wright R-3350 and that had more than few problems of it's own. It was also bigger in diameter and weighed as much as the R-2800 except it had a single stage supercharger compared to the R-2800s two stage. Performance at altitude without turbo was not good.
Version/s used in B-29 were a complete re-design from the 1940-42 version and gained around 200lbs in weight.
For the Hellcat the only poorly performing engine was the R-2600 installed in one prototype for a short period of time. Of course with a 12,000lb fighter (clean) even 2000hp is a bit low
Adding bombs/drop tanks could push the weight up by another ton or more. The Bombs/drop tanks may not have been part of the original specification. Hellcats got water injected engines not long after they became available and planes in the field were often retro-fitted.
As has been noted by others the US tended to go a bit overboard in specifying guns and ammo. Few other fighters in the world carried the weight of guns and ammo that US fighters did. A Hellcat carried over 1150lbs of guns and ammo, this does not include mounts, gun heaters, charging systems, ammo bins/chutes,etc.

Early US fighters suffered from being designed before armor and self-sealing tanks became standard. This added 400lbs or more to such planes as the F4F, F2A, P-39 and P-40. Uprated engines didn't always show up in time to handle the weight increase which was not helped by the Army and Navy increasing the number of guns and/or ammo carried. Pre-war planning for the Navy included yanking two of the .50 cal guns when the F2A and F4F carried even a pair of 100lb bombs. Something that never happened in service.
Blaming the companies that built the aircraft or engines doesn't seem quite fair.

I don't see it as blaming the companies, at least not all of them. I guess the point I was trying to make, and I believe is true to this day, is that typically speaking military equipment is always horrible when it comes to version 1. Often needlessly. Having served myself I can attest to time after time upon receiving new equipment we encountered difficulties that rendered it either useless or far less useful than intended. I cannot think of a single instance where this was necessary or could not have been avoided by simple reality checks of the requirements vs delivered specs. As far as blame, there was plenty of that to go around I am sure. It was unpatriotic to discuss war profiteering during and after the war but in the decades that followed it became readily apparent most manufacturers dined at that trough to some degree or another.

 

[drgondog]

No fighter pilot complained about Too Much Power - ever.

The designers placed the most powerful powerplant available to them at the time. Mission creep often dictated more power. Performance expectations dictated more power.

The engine manufacturers balanced production requirements of the respective War Board authorities with R&D and Test to enable future increases in existing airframe envelopes.

 

[drgondog]

I don't see it as blaming the companies, at least not all of them. I guess the point I was trying to make, and I believe is true to this day, is that typically speaking military equipment is always horrible when it comes to version 1.

I disagree. There are many examples where the 'new' product was a significant improvement over the item it replaced. In the case of high technology many new hardware introductions experienced start up issues that took time and money to fix to acceptable levels. Just to name a few products introduced into the military I would include the Colt 1911 or the Browning M2 or the Garand M-1 or P-51 Mustang or F6F Hellcat or F-16 Lawn Dart or M-1 Abrams tank to name a few

Often needlessly. Having served myself I can attest to time after time upon receiving new equipment we encountered difficulties that rendered it either useless or far less useful than intended. I cannot think of a single instance where this was necessary or could not have been avoided by simple reality checks of the requirements vs delivered specs.

Which 'new products/equipment' didn't meet your expectations? Acceptance testing is to Spec. Sometimes specs were waived to get a new system introduced but by and large they are held up until 'fixed' to specs. The Designer, builds to Spec - as defined by requirements. Part of the issue in systems like the F-35 is that the DoD wishes to force the vendor to not only meet spec but also define how to 'build' by virtue of issuing many Mil Spec/Design standards that often serve no purpose other than introduce a lot of overhead during the design process.

As far as blame, there was plenty of that to go around I am sure. It was unpatriotic to discuss war profiteering during and after the war but in the decades that followed it became readily apparent most manufacturers dined at that trough to some degree or another.

Your opinion, you are welcome to it.

 

[drgondog]

I read, a LOT, and I have read probably 200+ books dedicated to WW2 aircraft. I also read about modern aircraft. And I have noticed over the years a constant refrain. Without any exception I can find every aircraft ever delivered during WW2 was initially underpowered or had no Super or Turbo chargers and therefor was restricted to lower level performance envelopes.

Pretty silly comment. The aircraft designed was designed selecting the best powerplant available at the time based on the approach (i.e Radial for max power/less fuel economy/high drag vs Inline for minimizing drag and better fuel economy) selected to meet the Specs the contractor believed most important. The AAF/USN accepted the bid based on the design attributes and cost proposed.

And it does not matter the year they were first delivered from 1938 all the way up to and including 1945.

Oh, really. Care to comment on the underpowered F8F or P-51H? or B-29

Now I expect bugs, design tweaks based on usage and testing. But underpowered? No. So why? In every case better engines were already available, costs were in many cases comparable, and by 1940 we already knew we needed 2 stage Supercharges to preserve performance at altitude.

Care to cite specific examples? Name the airframe and engine choice then point to a better solution available in production.

Yet over and over again aircraft were delivered with underperforming engines, including all the favorites, the Mustang, Hellcat, Spitfire, you name it. Reading first hand accounts from the pilots that tested these aircraft read like boiler plate. Great maneuverability, great handling, no power, no legs at altitude. Ad nausea.

The Mustang is a classic example of not knowing what you are talking about. It was designed to RAF proposed specs and basically as a 'Better than P-40" for which high altitude performance was not a requirement. 90% of RAF combat specs were for SL to medium altitude, save recon and interceptors. The Brits were also far sighted enough to direct NAA to consider Merlin - if asked, down the road. The Primary problem for NAA to even consider the Merlin is that none were available. The secondary problem is that the future Merlin 61 and 66 were not even produced. nor incorporated into an existing design.

I like to think designers are competent people but what was wrong with these idiots all through the war and constantly delivering underpowered aircraft?

Pretty bold talk. I suspect you would not be able to interpret and understand an RFP, much less actually translate mission requirements to Weight fractions, preliminary drag estimates for the size airframe suggested by the weight fractions, balance against powerplant (s) and specific fuel consumption, then iterate against mission statements and weight fractions.

Heck a step grandfather I had was a carrier pilot in the pacific and mentioned case after case of aircraft being "beached" until better more powerful engines arrived. The F4U was a classic example, it took the British to figure out how to land the thing on a carrier. And it took a year for better engines to catch up with it.

The F4U quickly found a home in the USMC while carrier trials were on-going. The F4U never had 'an engine problem', nor was it ever underpowered for any mission it was designed for. Ditto the F6F. The R2800 evolved to improve power and altitude performance but the basic airframes when they went into combat were superb.

 

[Token]

Rob Porter,

Recurring theme, well maybe there is another way to look at it.

I think it was true then as is now, and that would be the quest for more power. Look at the Spit, Mustang, Fw-190, Bf-109, F-15, F-16, F-18. All were launched with a "given" engine and later upgraded. Also remember that the upgraded engines are for improved excess power (advantage over earlier version as well as over what the enemy has currently fielded) & improved performance (to include a heavier aircraft via production changes or combat load out) as well as improved reliability. You can say the early models were underpowered, but would think that the airframes were aerodynamic stretches to current technology as were the engines. Everybody was working their collective buttocal areas off (airframe & engines), and incremental changes were to follow.

^^^^this

Probably the only time this would NOT be true is when an aircraft was designed around an existing proven engine.

Anytime you are developing a new high performance aircraft (most military aircraft are definitively high performance in some way) you are typically leveraging or counting on developing engines also, not existing engines. Even if the developing engine is based on an existing engine there are engineering risks and timeline issues.

And so a lot of aircraft prototypes or early marks fly with less than desired engines, because the "goal" engine is still coming. But at the same time the engines are being improved so are the airframes. And when the goal engine arrives the airframe has been improved and could benefit from an even further improved engine, so that even when the originally defined power level arrives the airframe could carry/use more power.

It can be a moving target.

Could K5054, as it flew, really have used the Griffon 101?

T!