Qualities that made for a great aircraft that don't show up in performance stats.

Schweik said:

My understanding of the story is a bit more convoluted. According to Don Berlin himself, before they came up with the P-40, they had passed through another unsuccessful stage, the turbocharged YP-37. A rather more radical departure from the original P-36 design, of which 11 were manufactured. It managed to go 340 mph at 20,000 feet, which is decent performance for the time, but only when the turbo-supercharger was working. Which was intermittent at best.

View attachment 518549
This too has the same wings. But is it a P-36?

The added length was due to an experimental turbo-supercharger. Don Berlin... we all know who he is right? Said of the plane that "The YP-37 was a nice looking ship, but they were not reliable. The [turbo] supercharger was simply not working, and we didn't have time to develop that too."

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The extra length was not due to the turbo, which was located beneath the engine, and which can be seen in the image you have posted. The wastegate exhaust is pointing down just ahead of the wing leading edge, about level with the front of the wing fillet where it meets the fuselage..

Instead, the extra length was due to the coolers (engine coolant radiator and intercooler), oil tank and fuel tank being mounted in the area behind the engine. The slots on top of the cowling, about level with the wing tips in the above picture, were for the discharge of air from the coolers.

The turbo was experimental in as much as they all were at that point. The XP-37 used the original style turbo, where the intake air for the compressor was taken through the area between the compressor and turbine, an attempt to keep the centre bearing cool. But this was woefully unreliable.

The YP-37 used the new style turbo where the compressor was reversed (the back of the compressor was on the turbine side), so that its intake came in directly. It was still unreliable. About that time the General Electric turbo was redesignated as B-1. Some YP-37s may have been fitted with the upgraded B-2. These were the first of the B-series turbos that would feature on the P-38, B-17 and B-24.

Schweik said:

Thus the birth of the XP-40 you show above, with the oddly placed radiator scoop and lack of supercharger intakes.

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The placement of the radiator scoop wasn't that odd, as other aircraft had tried the same. Notably the Hurricane (though it was further forward).

The engine intake is on top of the cowl, just aft of the point where the nose stops tapering, or just ahead of where the exhaust outlet is.

All Allison powered P-40s had some form of intake scoop on top of the cowl, as the V-1710 was fed by a downdraft carburettor.

Schweik said:

By this time, Berlin had already had the radiator on the XP-40 moved to the front, improving speed though it was still apparently not quite ready for prime time.

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The radiator was moved forward because it didn't work well and, probably, created excessive drag.

The Hawker Tornado went through a similar issue, where it originally had a Hurricane style radiator, but that was found to not work. The radiator was moved forward into the airstream which was not compromised by boundary layer, boundary layer separation and turbulence.

Schweik said:

This roughly doubled the unit cost from the P-36 at $23,000 to the new P-40 at ~$46,000

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Please make sure you are comparing apples to apples. Many times contracts are quoted (usually for the low numbers) for the airframe only.
The high numbers are for the complete aircraft but that takes some good accounting as such things as (but not limited to)
Engines.
Propellers.
Radios
Oxygen equipment.
Some instruments.
Guns.

were supplied by the government. and were paid for by the government under separate contract.
The Allisons that went into the P-40s in that April of 1939 contract were paid for by the government and supplied to Curtiss by the government at no cost to Curtiss.

Engine prices are all over the place.
The initial order for Allisons for the P-40 contract was for 393 engines (not enough for the contracted airframes) but this was soon changed to 837 engines of various models for $15,000,000 (more than Curtiss was getting for 524 airframes). However the contract was later changed to 969 engines for the same price.
Unless someone has a copy of the contract this also does not spell out the quantity of spare parts to accompany the engines. Another detail that can confuse contract prices
Allison prices were all over the place before/during WW II, in part due to the number of engines produced in a given year/contract.
In 1935/36 and Allison V-1710-3 cost $27,500 but they were only making 2/3 engines per year. 1939 saw the average price drop to $26,283 with 48 engines made. 1940 average price was $22,860 with 1,153 engines. 1944 saw $9,500 an engine with over 20,000 made but by 1946 the price hit $13,500 per engine due to small numbers (and two stage superchargers?)

Prototype work was expensive. Allison in the late 30s wanted over $7,000 to change an existing engine into a prototype for a new model.

For the P-40 one source says the April 1939 contract was for 560 aircraft at $12,872,398.00 at a unit price of $22,929.30.
This was subdivided into 524 complete aircraft, the equivalent of 36 aircraft as spare parts, one "skeleton" aircraft ($19,489.92), drawings, parts list (15 cents per sq ft), complete stress analysis and weight information. various manuals, handbooks and parts catalogs.

It may have cost $46,000 for the XP-40 or it may cost that amount to turn an existing P-36 into the XP-40 but the above figures show that the production P-40 airframes were nowhere near $40,000 dollars.
Curtiss billing records show that the 2nd P-40 (MSN 13034) was about $1900 more expensive than the 1st P-40 (MSN 13033) and that the XP-40 was number MSN 12424.

According to the Air Force digest, the unit cost of a P-40 started ~$60,000 in 1939 (presumably with the engine), and gradually dropped down to ~$44,000 by 1944. I've seen other quotes between $40 and $57 thousand. I've never seen a unit cost estimate as low as $20 thousand for the P-40. I'm sure you can quibble with this source, but it's enough for me.

It's an interesting chart - the initial unit cost of a P61 is more than a B-17 or B-24.

But more importantly to me, it also matches what I have in a couple of my books on the P-40.

And this says unit cost of a P-36 was ~$23,000 which seems to be about average of several estimates I've seen for various different versions.

So I stand by what I said earlier. The design change for the P-40, consisting mostly of adding the new engine and associated hardware, as well as more incremental changes of streamlining, tweaking cooling systems strengthening the wing and rearranging fuel and oil storage and so on, roughly doubled the cost from the older P-36 design.

Prior 1941, USAAC was paying for each R-1830 almost 15000 US$; each P-36 used one:

XBe02Drvr said:

Living forty miles from the Quebec border, I've observed an interesting shift in the language over the last five decades. In their increasing confidence in the strength of their culture and pride in their "Frenchness", our neighbors to the north seem to be drifting away from the Quebecois dialect I remember from my youth and closer to the Parisian French I was taught in school.
In the early 60s I was told I had to learn French as it was the lingua franca of international trade, diplomacy, and academia. My aunt and uncle in the foreign service made themselves understood in French in Taipei, Jakarta, Karachi, and Rangoon. Seems not to be so anymore.
Cheers,
Wes

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Continuing to fearlessly pursue this digression: my neighbours speak the Poitevine patois which is an origin of Quebecois as the peasants emigrated from here to New France. At least they speak it when they don't want me to understand them. Borderline Occitan.

Also, echoing Pben above, when I was in the Territorial Army in England we had signallers from Corby. Their Scottish accent was sufficient security for plain speech messages as no one else other than the 'Corby Highlanders' could understand them.

Never mind. Most of the English spoke Brythonic Welsh until it became cool to speak German and then were infected with French grammar to create what we now call English. I except the likes of Saint Patrick and 'King Arthur' who were well brought up upper class Romano Britons who spoke Latin amongst themselves and Welsh to the peasants.

tomo pauk said:

Prior 1941, USAAC was paying for each R-1830 almost 15000 US$; each P-36 used one:

View attachment 518646

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I'm surprised at how much more expensive the R2800 is compared to the R2600

Reluctant Poster said:

I'm surprised at how much more expensive the R2800 is compared to the R2600

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It's a lot more engine, more than the extra 200 cubic inches would lead you to suspect. It had the supercharging and the cooling capacity to handle higher power at higher altitudes, and was more durable when it came to abuse and combat damage as well as higher reliability and longer Time Before Overhaul. Building this kind of extra quality into an engine doesn't come cheap. (Why does a Rolls Royce auto engine cost more than a Chevy of the same displacement?) There's a reason for the saying: "Faith in God and Pratt and Whitney"!
Cheers,
Wes

yulzari said:

Most of the English spoke Brythonic Welsh until it became cool to speak German

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Did it "become cool", or was it imposed by Anglo and Saxon invaders?

Reluctant Poster said:

I'm surprised at how much more expensive the R2800 is compared to the R2600

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18 vs. 14 cylinders mostly.
To me it is the R-2000 where price went too much up, for an engine that was supposed be just a bit better R-1830. But then, R-2000 was never produced in tens of thousands, where effects of mass production drive the price down.

XBe02Drvr said:

It's a lot more engine, more than the extra 200 cubic inches would lead you to suspect. It had the supercharging and the cooling capacity to handle higher power at higher altitudes, and was more durable when it came to abuse and combat damage as well as higher reliability and longer Time Before Overhaul. Building this kind of extra quality into an engine doesn't come cheap. (Why does a Rolls Royce auto engine cost more than a Chevy of the same displacement?) There's a reason for the saying: "Faith in God and Pratt and Whitney"!
Cheers,
Wes

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Army was mostly buying 1-stage R-2800s (predominantly for B-26s, P-47s and C-46s ), so the supercharging type was same as with R-2600s.
Turbos (add-ons for engines, like it was the case with P-47's R-2800) were purchased separately.

It makes sense the engines were the most expensive part of the plane by far. Really puts into perspective when you read the nonchallant way they would burn them out in a few weeks.

Schweik said:

It makes sense the engines were the most expensive part of the plane by far. Really puts into perspective when you read the nonchallant way they would burn them out in a few weeks.

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It also makes sense that a P-36 that supposedly cost 23000 US$ will never fly, since it lacks the engine that costs another 14900 US$, if not also a prop, guns and radios.

tomo pauk said:

18 vs. 14 cylinders mostly.
To me it is the R-2000 where price went too much up, for an engine that was supposed be just a bit better R-1830. But then, R-2000 was never produced in tens of thousands, where effects of mass production drive the price down.



Army was mostly buying 1-stage R-2800s (predominantly for B-26s, P-47s and C-46s ), so the supercharging type was same as with R-2600s.
Turbos (add-ons for engines, like it was the case with P-47's R-2800) were purchased separately.

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I'm not so sure the price difference is due to the number of cylinders. The R 1830 and R 1820 are very similar in price.

swampyankee said:

I've read somewhere that the average people during the pre-railroad age tended to travel fewer than 20 miles from their home village. It wouldn't have helped that many countries -- including England -- limited the travel of people of the laboring classes for many years.

Certainly, until the Reformation, educated persons would be expected to read and write Latin. Indeed, this is something that complicates study of literacy during this time frame: a person who could, for example, only read and write English (to keep, say, business accounts) may not have been considered to be literate. Wallace was also, if I remember, from the part of Scotland where the first language of most people was English.

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Supposedly being able to travel more than 20 miles marked the end of the village idiot.

Reluctant Poster said:

I'm not so sure the price difference is due to the number of cylinders. The R 1830 and R 1820 are very similar in price.

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Certainly, there is much moe to the price of en engine than just a number of cylinders. Whether the engine is mass-produced, how much of extras engine is supposed to have (supercharging type - Army didn't used much of 2-stage R-1830s, does it have a generator or not, fuel distribution type), how much some legacy tech or part can be used, engine displacement etc. The R-1830 barely got any improvement from some time 1942 on, while R-1820 did, and development costs money. Part of the price difference might stem from fact that P&W was more relaxed towards license-production, where prevoius automobile factories were converted to make engines, while Wright preferred it's own factories?

tomo pauk said:

It also makes sense that a P-36 that supposedly cost 23000 US$ will never fly, since it lacks the engine that costs another 14900 US$, if not also a prop, guns and radios.

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Yeah I think you are right.

I got that number from the Wiki, but I went and cracked some books and I think you are correct. It looks like the cost was ~17k without an engine and around ~30k with an engine, to as much as $37k for some of the foreign contracts. So I hereby retract my theory about the price. And I have another reminder not to trust Wikipedia...

yulzari said:

Continuing to fearlessly pursue this digression: my neighbours speak the Poitevine patois which is an origin of Quebecois as the peasants emigrated from here to New France. At least they speak it when they don't want me to understand them. Borderline Occitan.

Also, echoing Pben above, when I was in the Territorial Army in England we had signallers from Corby. Their Scottish accent was sufficient security for plain speech messages as no one else other than the 'Corby Highlanders' could understand them.

Never mind. Most of the English spoke Brythonic Welsh until it became cool to speak German and then were infected with French grammar to create what we now call English. I except the likes of Saint Patrick and 'King Arthur' who were well brought up upper class Romano Britons who spoke Latin amongst themselves and Welsh to the peasants.

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I live on one of the fault lines of English language dialects, the river Tees at one time formed the informal English Scottish border. To the north for a long time was a type of no mans land between the two where the dialect is like Geordie based on Norse. To the south over the moors is the vale of York rich and guarded farmland which was also the Danelaw before the Normans. One word that makes me laugh is "Skelp", in North East England and Scottish slang it means to hit, "give it a skelp" or "he skelped me", but it is also a technical term in pipe and gun making for the raw material that pipes and guns are made (I presume from the smith industries of forging and hammering). Within a week of arriving in Saudi Arabia I was presented by a Japanese welding engineer the new "Skelp end weld repair procedure for 56" pipes".

tomo pauk said:

Army was mostly buying 1-stage R-2800s (predominantly for B-26s, P-47s and C-46s ), so the supercharging type was same as with R-2600s.

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That is so, but even with the single stage charger, Pratt's altitude performance was better.
Cheers,
Wes

tomo pauk said:

Part of the price difference might stem from fact that P&W was more relaxed towards license-production, where prevoius automobile factories were converted to make engines, while Wright preferred it's own factories?

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P&W had confidence not only in their own design and build quality, but also in their ability to induct a bunch of tin lizzie constructors into the arcane art of high performance aircraft engines. Wright either couldn't be bothered or didn't have faith they could pull it off. Like the original Wrights, they were control freaks.
Cheers,
Wes

XBe02Drvr said:

Did it "become cool", or was it imposed by Anglo and Saxon invaders?

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If we look at the later French invasion, French became the posh language but the peasants kept to their German, gradually assimilating French loan words and grammar until the invaders went over to the new hybrid too 200 years later. 'English' has scarcely any of Brythonic in it and vanishingly small Brythonic place names persisting in England. The mechanism for the change is much argued over in academic circles but the rapid assimilation of German dress, building habits, land use and countless other things suggest that the new 'English' were not just top dogs but were also working down at the coal face with the local peasants. Hence the French were acting as the managers so the workers had little day to day contact but the English were at foreman and artisan level too so worked with the peasants every day. It is sometimes also argued that the Germans had been emigrating to Britain for generations before the Romans left. What is now agreed is that the English did not invade in vast numbers and drive the Britons out. The English were only a part of the population but got the best bits and ran the show. So many modern villages have names that basically say 'this is the settlement of (insert German name)'.