Curtiss-Wright: Loss of Don Berlin and downfall

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If that was a V-1710-33 pushed to 3400 rpm on standard 100 octane fuel and 75" MAP, that would seriously imply the detonation limits with that supercharger weren't as extreme as Allison's documentation later implied with the 9.6:1 engines. A 7.48:1 ratio engine would be running too slow at 3400 RPM to push 75" at SL, but maybe there's more context here or it was an 8.1:1 supercharger used? That or the 75" MAP and 3400 RPM runs weren't used in conjunction.

Pushing 3200 RPM at 75" MAP without ram would result in something close to 1800 HP at SL with the -33 going by the chart on Peril's site (and approximating the 3200 RPM curve). I could see that sort of strain being used for demonstration purposes, but if the AVG ever used that as emergency power on their P-40Bs it's no wonder they stripped reduction gears and burned through engines. There's obviously a ton of middle ground between the conservative military rating used by the USAAF and full-out overrev AND overboosting especially on those early engines.

With that sort of engine abuse, those P-40s would have been screaming at low altitude, though and should have smoked Spitfire Mk.Is and IIs in WEP ... or Mk.Vs for that matter. (might have nearly matched Spitfire Vs in altitude performance with that overrev -plus the P-40B being substantially lighter than later models) Using overrev only at altitude would have been a lot easier on the engines too.

If it genuinely had been acceptable to overrev the engines for WEP as routine, then the 8.8:1 supercharger ratio wouldn't have been that big of a limit either and both the backfire screens and kink/bottleneck in the intake manifold would have been bigger priorities for supercharger efficiency improvements.
 
It seems like Curtiss didn't know when to say 'no' or 'stop' or 'this concept needs a lot of changes' ... taking on too many projects and many with questionable specifications, and just going along with it rather than focusing more aggressively on fewer projects and being more selective in which projects got pursued. (and being willing to also do more than just decline taking on some new projects but also having a greater willingness to rationalize some of the questionable requirements; being more proactive and innovative rather than just trying to take on impractical if not impossible design requests) Putting more resources into curing the problems with the C-46 would be among that same redistribution of resources.

Problems with fighter development were a bit different there though as some of those requirements were less unrealistic or were independent projects started by Curtiss in the first place. The more consistent problem there seems to be the engines selected and either Curtiss or the USAAF consistently making problematic choices that underperformed or had to be replaced and cause further delays.

Had they focused heavily on a fighter optimized around a big radial engine as the followon to the P-36/P-40/P-40 development programs they might had something much more workable much sooner. Switching between the likes of R-2600 and R-2800 with or without turbochargers would have been a lot less hectic than the number of engine changes and compromises and redesigns the XP-46/60 programs saw and the XP-55 likely would have fared better if designed around the R-2600 or R-2800 from the start. (the XP-46 had been largely a new aircraft as it was, so putting the same engineering effort into a machine built around those radial engines would have made plenty of sense)
 
Ah yes, I see the error of my ways. We never have produced a -33. All our Allisons were -89 series or above since all the people ordering them wanted the relaibility and power of late models. We DID supply one early engine case with -100 Series internals, including 12-counterweight crankshaft, but that was by direct owner order. We basically made E, F, and G engines with the accent being on E and F. The only people who seem to want the G series wanted to go racing and usually want the rods.

We were hoping to find someone who wanted to go racing with a 3,000 HP Allison and we could supply the engine, but we weren't going to fund the entire project ourselves including airframe. The shop was an engine shop, not an airframe shop ... we supplied engines and sometimes propellers and propeller hubs and custom engine services, such as fixing the screw-ups from other ALlison shops. at least that one is a good business!

Love the O-47 shot above and am working on one now and for the next several years. It needs a lot of TLC and newly-fabricated parts to get back in the air.
 
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My mention of the -33 (or C series Allisons in general) was regarding the demonstration(s) to Chennault and AVG operations with P-40Bs (and Cs). I don't think they got any -39 (F3R) powered P-40Ds or Es until after the Flying Tigers transition to USAAF command, but I could see them using 'unconventional' engine procedures there as well.

Of course, comparing early and late F (or E) series engines would show changes too, but not the same dramatic change in reduction gear design.


If we had similar information on V-1650 or Rolls Royce Merlin engine abuse, it'd be easier to get a picture of how much potential the V-1710 had for more heavily stressed emergency power than the USAAF or Allison officially rated it. (I want to say I recall mention of the Merlin being less tolerant of overrevving than the Allison, but I'm not sure)


I do specifically recall references to the AVG had engine failures in both the reduction gears and thrust bearings (both specific to P-40B/C operations)
 
According to "Vee's for Victory" there were 4 'different' crankshafts used in the Allisons. The first 3 look identical, at least from a distance. I don't work on them so there may be minor visual clues. The first were 'plain' crankshafts which I believe the C-33s got. The next version was shot peened, different surface texture? much improved fatigue life. I don't know when it was introduced. Then they nitrided the crankshafts in addition to the shot peening. This allowed for another major increase in fatigue life.

Each step allowed for roughly an unlimited life at a stress level that the preceeding step would only tolerate for a very short period of time. Nitriding was introduced in early 1942 and allowed about a 70% increase over the old plain steel (not shot peened) Crankshaft in stress levels for the crankshaft with both cranks operating at a level that they could sustain for an unlimited duration. Also in 1942 the casting method for the engine blocks changed. The new method required about 10% fewer operations to manufacture ( casting was closer to finished dimensions), weighed a bit less and was stronger. There may have been changes in the vibration damping system between the "C"s and the later engines. Or between certain models of the later engines.

The "C" series engines, according to the book, were rated at an overspeed of 3600rpm. The "E" and "F" engines were rated at 4100rpm for overspeed when introduced and the "G" series with the 12 counter weight crank was rated was rated in excess of 4400rpm.
This was not theory. As part of the engine type test the engine had to survive running at that speed for 30 seconds and do it a number of times during the duration of the test, usually a minimum of 10 times, depending on contract.

Now what happened in the field could be way different and what an individual pilot did either in pursuit of an enemy nearly in his sights or when trying to save his own life could be different also.
However, trying to operate "C" series engines at power levels used by "E" "F" engines, while possible short term, was at a lot higher risk and definitely shorter engine life, let alone the reduction gear problem.

The US Air Corp had the problem of rating engines for combat use with the factory 3000-8,000 miles away from the front lines. Spare engines and spare parts for even an in theater overhaul shop had to be transported those distances. They had to trade off short term performance gains of the aircraft vs blown engines, making men fly planes with engines in questionable condition, not having enough planes in service to fly the desired number of missions in a day and so on. Which more hazardous to a pilots life, not being allowed to use WEP settings and flying in a 12 plane formation to meet the enemy or being allowed to use WEP settings and having an 8-9 plane formation to meet the same number of enemy aircraft?
Maybe they did get it little wrong, maybe they got it a lot wrong.
 
Gen. ALlison DID abuse the crap out of early Allisons and he got away with it. We stayed away from the early engines because the parts are VERY scarce and the market is nothing. Over the last 15 - 20 years they have built up only about 3 - 5 early Allisons when the parts could be located and were OK for flight use. They went into meticulous restorations and they even specified pal-nuts on the cases! I know one went into a beautiful, polished P-40C that went to Europe and sometimes flies at Duxford.

Joe has about 125 E or F Allisons ready for overhaul and could build as many as about 12 - 15 G models if anyone ordered them. They have heavier cases and heavier internals and many parts are NOT interchangeable with E and F series engines. He also has one PT boat Allison complete with flywheel and V-Drive adapter and two or three Auxiliary superchargers like used on the P-63s as well as several remote nose cases and driveshafts as used on the P-39 and P-63, ready for overhaul. Any of these can be built up right or left hand turn ... it is a simple change when buiding one but horrible to CHANGE one. You basically have to disassemble the entire engine to swap rotation but it is quite minor to build it up from parts for either direction of rotation. The only really DIFFERENT parts are idler gears and the distributor wiring harness. The rest of the parts just swap ends and turn the other way in the case. You also need a left-hand turn starter and starter cog. Everything else is the same ... except, of course, you DO need a left-hand propeller and spinner for your aircraft to actually fly it.

Joe did one left-hand engine for Paul Allen's Il-2 and another for a MiG-3 flying in Russia. He is doing more for the Russians. The only other aircraft that uses a left-turn Allison is the P-38 and the world flying population is only 6 or 7 at this time ... soon to be one or two more, depending on schedule. So the market for them is limited at best. Almost all are right-hand units.

Here is a shot of the O-47 I am working on:



And here is the current state of the starboard stub wing leading edge:



These were some 4 months ago. I'll get some more Saturday for an update. You can see I've circled some holes on the left rib where earlier volunteers drilled them off quite incorrectly and we'll have to repair that.
 
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Is there information on any similar testing requirements for the Merlin? (Packard or Rolls Royce)

Indeed and it seems likely that the AVG abused their engines beyond what would have been practical in broader USAAC (or RAF/Commonwealth) use and probably beyond the sort of stressing Merlins were pressed into during the BoB.

It's the relatively modest increase in military power rating from the C to E/F that's more puzzling along with operating RPM limits remaining the same 2600 and 3000 RPM. The conservative ratings applied to the C series engines seem a good deal more merited though I wonder if the more sensitive nature of those early engines contributed to the USAAF's conservative rating of later models. (aside from AVG operations, I'm not aware of specific high levels of abuse of engines in early P-40s but if there were such wider spread problems, I could see overreacting with too strict/conservative procedures applied to the later models would make some sense)

Either way, they'd have needed specific testing for various alternate WEP settings before formally adopting them for combat and that would mean more funding/resources for expedited and exhaustive engine testing specific to high power levels and high manifold pressures (or just high RPM) for more extended periods.

Increased maximum RPM while not under excessive load (say with power levels within the existing military power ranges) used exclusively at/above the critical altitude would be another area for testing. Somewhat like was allowed for some DB 601 models to improve altitude performance.

That would certainly be a big difference in context compared to the Merlin, and I suppose even the Packard Merlins would have much more immediate access to parts and extensive maintenance resources in the ETO than the V-1710 would. (in the PTO it would be another story though and the same would apply to any RAF fighters outside of the ETO)

In any case, having more testing data available for planning purposes even if officially not recommended or outright restricted in use by the USAAF would be more useful than individual fighter groups, squadrons or even individual pilots resorting to experimenting on their own.
 
Neat! I wasn't aware there were any Tomahawks left in flying condition. (or airworthy C series engines for that matter)

Sounds like something better to do with an engine that's already due for a tear-down and rebuild. (kill two birds with one stone)





And Shortround, in regards to V-1710 logistics in the field, wouldn't it make sense to supply spare components to depots in Britian servicing Merlins? (the idea of full licensed production in the UK also came to mind, but that seems to make little sense given the engine production rationalization established in 1939, but dedicating enough resources to allow servicing/repair/rebuild of V-1710s seems more sensible) Unless, of course, that's what already happened historically.

The PTO would still be more problematic, though perhaps licensed production of the V-1710 would be attractive in Australia? They seemed to favor licensing American designs over British ones (mostly radial engines) and having that resource in the South Pacific might be useful even if still a great distance from most of the front lines. (much closer than the Continental US, though, let alone Allison/GM facilities) V-1710 powered aircraft were more critical for the PTO than ETO in general and having access to that engine might also make for more useful options in Australia's indigenous fighter project compared to their attempts using the single-stage R-1830. (a straight up license for the Allison engined P-51 might have made the most sense given the timing involved too, and given the existing relationship between NA and CAC and the Mustang Mk.I was in production before development of the Boomerang had even started)
 
Overhaul shops/facilities were established for a number of different types of engines in combat theater areas. You still needed to get the parts to these facilities and you needed a fair number of spare engines to keep the planes flying while the engines were being overhauled. A general rule of thumb was you needed about 50% more engines as spares than were installed in the aircraft. All this adds to the logistic 'foot print'. The Chinese 'purchased' 50 spare engines for the 100 P-40s for the Flying Tigers. How many made it to the forward fields may differ.
Overhaul/repair shops not only worked on engines that had used up their "service life" but worked on battle damaged and crash damaged engines. Some planes were rather notorious for nosing over and hitting their props which frequently required the engine being pulled and sent to the shop for repair of the propshaft/gears/nose casing. Often a 'look' at the crankshaft was needed. The 'look' might mean pulling the crankshaft and checking the runout to see if it was bent.

Australia did more than their fair share during the war but according to one source (wiki) had a population of about 7 million in 1940. Less than the population of New York city. There was a definite limit to what they could do. They did work up to some rather sophisticated designs but that took time/experience. Expecting 1944/5 production ability in 1942 may be asking too much. Australia's ability to manufacture machine tools, jigs and fixtures in large quantities was probably somewhat lacking.
 

Thanks for the scan! Great reply to the initial query.
 
I'd also been mistaken in thinking CAC had the R-2800 and/or R-2600 in licensed production at some point. It seems the R-1340 and R-1830 were the only war-time engines they had in production for warplanes and those were likely easier to manufacture than the V-1710 by a good margin.

With the mixed aluminum and steel tube (and fabric) construction, the NA-16 derivatives seem pretty sensible as well. The Boomerang project likely would have been more useful had development started earlier or if CAC had started with NA's NA-50 or NA-68 designs and progressed from there. (it would have been more useful than trying to engineer a competitor to the Beaufort in the Woomera, that and probably just sticking with some number of .303 Brownings for the armament, no fiddling with reverse engineering the Hispano -a .50 M2 license might have made sense but the smaller/lighter would probably be easier to fit into the airframe space/weight/recoil wise and already available)
 
Though there's a lot of discussion about the departure of Donovan Berlin, nobody seems to discuss WHY he left...

Graeme said:
Curtiss was falling slowly well before this due to administrative problems...
Click to expand...
So their attitude was: I will never go hungry again, so if they give me a contract, I'll book it no matter what?

Ralph Damon was the CEO from what periods?
 
After the P-40 there were zero positive airframe designs under Berlin's leadership. The XP-46 was oversold and under-delivered and the XP-60 series were of indifferent design. The XP-75 was arguably the worst design of all but he had a partner in Col and then General Oliver Echols who kept Curtiss, then GM/XP-75 in the biz when NAA/Mustang was being ignored.
 
gjs238 said:
Don Berlin left Curtiss in December 1941.
Was that a large reason for the fall of Curtiss?
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Admiral Beez said:
This made me think of Supermarine after RJ Mitchell died. Went from Spitfire to the rubbish Attacker, Swift and Scimitar.
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Bluntly, both these cases indicate serious management and cultural problems in these companies. No company should let itself be put into a position where the departure of any single employee, no matter highly placed, puts a company on a serious downslide.
 
Sounds like Apple after Jobs died. We can argue that Jobs didn't bring much innovation to his product categories, but there's no question Apple's massive success financially was due to Jobs. Now that he's gone, everything there that wasn't invented by Jobs seems to be crap.
 
Grumman is another example. In some ways Grumman was at the top of its game in the Mid/Late 60s. Aircraft developed on contracts won in the 60s would fill Carrier Wings composed of F-14s, E-2s, A-6s, they designed, built and performed flight operations for the Lunar Module an incredible contract. Leroy Grumman left the company in 1966, by '94 they were not in the phone book.

Tom Kelly was the Proposal Manager then Chief Engineer of the LEM, his Book Moon Lander offers a good view of Grumman in the 60s. He wrote when Grumman lost the Space Shuttle to North American Rockwell it was the beginning of the end of Grumman.
 
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Admiral Beez said:
This made me think of Supermarine after RJ Mitchell died.
Click to expand...

Sorry Admiral, so much wrong with this staement. It wasn't Mitchell that charted the development of the Spitfire throughout its career, it was Joe Smith, who made the decisions behind putting the Merlin 45 into the Spit II to create the V, then the Merlin 61 into the V to create the IX, then the Griffon into the Spit IV prototype to create the XII, then the Griffon 60 series into the VIII to create the XIV. All these were smart decisions that kept the type at the front line throughout the war. In fact under Smith you could say this is how a pre-war design should have undergone development to remain relevant.

As for the Spiteful-Attacker-Swift-Scimitar line, can't really put that to one single personnel change. The Spiteful was an exceptional fighter destined to become irrelevant due to jet engines, then the Attacker was a half hearted attempt at a jet by mating the Spiteful/Seafang wing with a new jet fuselage, which gave it lower performance than the MiG-15 with the same engine despite being smaller and lighter. The Swift was just plain bad designing; the woeful state of the early Avon certainly didn't help, but it suffered from aerodynamic and mechanical flaws during its development. The Scimitar evolved from a twin-engined fighter development, which should have been something of a winner for Supermarine, that the Scimitar evolved into a twin-engined carrier based bomber was not because the initial design was flawed, but because they couldn't interest the Air Ministry in what it had to offer. That it suffered aerodynamically as the Swift did can be put down to the same reasons as the Swift - not enough R&D at the wind tunnel end.

Again, the departure of Mitchell had no impact on any of this though; Smith masterfully commanded the Spitfire through the war, there was no reason to believe that post-war the Supermarine design office wouldn't be able to match its success, just like Berlin's departure on the fate of Curtiss.
 

It didn't require a genius to install Merlin 45 in the Spitfire II - it was basically the same engine as the Merlin XII. That Spitfire was conductive to receive installation of ever-heavier and more powerful engines is a testament to the excellence of the basic design, and for that we can credit far more Mitchell than Smith. Mitchell also designed the Supermarine racers, the Spitfire was not a thing of just 'getting lucky'.
We can also give credit to Beverly Shenstone here, the creator of the wing of Spitfire.


The proof is in the pudding - unlike with Spitfire, in post-Mitchell years the Supermarine design office didn't make an over-average airframe for a combat aircraft.
 
Many of these companies made a few turkeys along the way. At certain times however they may have been working on multiple designs and one turkey (or two) at the same time there was a success wasn't enough to pull the company down. At other times the orders were not so plentiful and more was riding on each design, a single turkey at such a critical time could spell disaster (or a short string of turkeys).
In the "jet age" things get more complicated as the success or failure of a plane depended on things outside of the airframe makers control. The US Navy doomed a number of planes to mediocrity or worse by insisting on Westinghouse engines for example. Or issuing requirements for planes to use Missle XX which turned out to not work very well. Or an electronics system/suite that took years to get right.
British aerospace was in a poor position during and after WW II due to a lack of engineers (and support like wind tunnels) as planes rapidly grew in complexity.

Curtiss may have diluted their talent pool by trying to do too many projects at once. Or been the victim of bad luck in the form of bad timing.
Curtiss got involved with several projects involving pressure cockpits and single engine fighters powered by R-3350s with contra rotating propellers that took longer than usual to get to flying status.
Poor management may not have given proper guidance to the design teams. Or bid on too many projects at once.
 
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