Earlier Tempest/No Typhoon

[Edgar Brooks]

Does your material tell anything about the "uprated" Peregrines? Maybe HP or critical altitude ... or some description?

I doubt that it ever will, since, if there were any, it'd be experimental only. This will bring protests from the "defenders of the faith," but the Peregrine could not run on 100 octane on a regular basis (whatever the Whirlwind Pilot's Notes say.) It was to be used in emergencies only; uprating the engine to take 100 octane 100% of the time, would have meant so many modifications, it would virtually have been a completely new engine, and that's what made Rolls-Royce baulk.

 

[Greyman]

whatever the Whirlwind Pilot's Notes say

 

[GregP]

Thanks guys. I appreciate the information.

Too bad they didn't design the Wirlwind a bit bigger for the anticipated engines, it might have had a future. From what I read, it was a pilot's airplane. Of course had they done so, the question then was whether or not any Merlins would have been available, and from what I'v read, the answer is probably not more than a few, which would have left te Whirlwind right back where it wound up to start with.

I wonder how it might have fared as a slightly bigger plane with a pair of turbocharged Allisons. The P-38 did better than OK once the issues were worked out. I don't think it could have been done with a pair of Daimler Benzes since the war would have cut off the engine supply, and Hispano Suizas would not have given much more power than the Peregrines did. That doesn't leave a lot of possible choices in the world of the mid to late 1930's.

 

[pbehn]

Too bad they didn't design the Wirlwind a bit bigger for the anticipated engines, it might have had a future. From what I read, it was a pilot's airplane. Of course had they done so, the question then was whether or not any Merlins would have been available, and from what I'v read, the answer is probably not more than a few, which would have left te Whirlwind right back where it wound up to start with.

When merlins were available they made the Hornet which shows what was possible. Until then the RAF preferred Mosquitos.

 

[pbehn]

If if it had German crosses and swastikas we would be looking at books No 13 and 14 about it and at least 4 dedicated websites

True but winning the war with a little more in hand isnt as attractive as changing the whole course of history.

 

[Shortround6]

True but winning the war with a little more in hand isnt as attractive as changing the whole course of history.

I would note that there were only 100 Spitfire MK VIs built, 140 MK VIIs and 100 MK XIIs.

Americans built 130 P-47Ms?

It would be interesting to see with how many squadrons and for how long these limited production aircraft were in service with.

Sort of as a check to see if the Whirlwind's service was below, at or above average.

 

[Greyman]

I would note that there were only 100 Spitfire MK VIs built, 140 MK VIIs and 100 MK XIIs.

Americans built 130 P-47Ms?

It would be interesting to see with how many squadrons and for how long these limited production aircraft were in service with.

Sort of as a check to see if the Whirlwind's service was below, at or above average.

Still not really comparable I'd say - because there existed so much overlap in the training/supply chain for those 'small run' types compared to the Whirlwind, which had different ... almost everything.

 

[Glider]

I would note that there were only 100 Spitfire MK VIs built, 140 MK VIIs and 100 MK XIIs.

Americans built 130 P-47Ms?

It would be interesting to see with how many squadrons and for how long these limited production aircraft were in service with.

Sort of as a check to see if the Whirlwind's service was below, at or above average.

The RAF's rule of thumb for planning was that 50 aircraft were needed to keep one squadron operational in Europe for six months.

 

[Milosh]

The P-47M arrived at the end of 1944/beginning of 1945 and had all kinds of problems not really becoming truly operational till the last few weeks of the war in the ETO.

 

[Edgar Brooks]

I would note that there were only 100 Spitfire MK VIs built, 140 MK VIIs and 100 MK XIIs.

The VI, powered by a single stage Merlin, was replaced as soon as possible, by the two-stage Merlin-powered VII, which was superseded, in the Mediterranean, by the high-altitude VIII with extended wingtips. The Air Ministry did tend to give their pilots better airframes as soon as they were available, which seems a good idea (to me, anyway.)
The XII was ordered because of a temporary shortage of low-altitude Merlins, so the low-altitude Griffon was used instead. Not a very exciting, or controversial, reason, but true, nevertheless.

 

[pbehn]

I would note that there were only 100 Spitfire MK VIs built, 140 MK VIIs and 100 MK XIIs.

Americans built 130 P-47Ms?

It would be interesting to see with how many squadrons and for how long these limited production aircraft were in service with.

Sort of as a check to see if the Whirlwind's service was below, at or above average.

I am not knocking the Whirlwind. It makes perfect sense to me that the Whirlwind was kept in service even only 2 or 3 squadrons while a threat of invasion existed and while attacking ground targets in France was wanted.

My post was a reply to :-
If if it had German crosses and swastikas we would be looking at books No 13 and 14 about it and at least 4 dedicated websites

Somehow a huge number of people want to campaign for the underdog and if only a little more resources were put into a brilliant design then the war would have been "different" I dont know why so many people want the Nazis to win in the first place but from any rational view point they had way too many projects ongoing for any of them to be successful. The British, in the face of defeat, had to rationalise and the peregrine was axed along with it so was the Whirlwind. Nazi Germany in the face of defeat pursued a huge number of zany solutions. No matter what field of military endeavour they had a wild design and frequently many wild designs. There was a recent thread about "Amerika bombers" Germany had many more "designs" for bombing the USA than the USA had for bombing Europe and the USA had the resources.

The rationalisation that halted the Whirlwind also officially halted the Mosquito although some work was done privately, eventually when the prospects looked better for the UK projects were re started and the Mosquito progressed, the Whirlwind had no engines and so had nowhere to go.

 

[kool kitty89]

For what it's worth Westland's projected (spring 1940) development of the Whirlwind included:

- uprated Peregrine engines
- Rotol airscrews
- new gun nose unit with continuous feed for the four Hispanos, three .303 Brownings and a 27-gal fuel tank
- additional 35 gallon tank in rear fuselage
​

Hmm, interesting, but no mention of addressing the problems with the slats? If they were operating violently enough to damage the wing structure (rather than the slat mechanism being too weak and damaging itself) that would seem to imply a need for a better shock absorbing system. If it was problems with vibration due to aerodynamic interference when the slats were deployed, that's a different problem and one that would require aerodynamic refinement. (also a problem exacerbated by lack of wind tunnel testing) The latter case seems more likely, but also more difficult to fix.

I doubt that it ever will, since, if there were any, it'd be experimental only. This will bring protests from the "defenders of the faith," but the Peregrine could not run on 100 octane on a regular basis (whatever the Whirlwind Pilot's Notes say.) It was to be used in emergencies only; uprating the engine to take 100 octane 100% of the time, would have meant so many modifications, it would virtually have been a completely new engine, and that's what made Rolls-Royce baulk.

It would be problems with using +9 lbs boost at 3000 RPM that would be relevant here, not 100 octane fuel. (the 100 octane fuel blend used in Britain COULD be problematic in its own right, but that would be present at all power levels and not relevant here, I think)

I wonder what was so different in the Peregrine that prevented it from being abused like the Merlin III, perhaps lack of some of the troubles the earlier Merlins suffered that forced more aggressive engineering fixes?

Use of 100% glycol at high power levels alone could be a serious problem, and Shortround already mentioned that applied to the Peregrine (the Merlin had some trouble there too -the Curtiss V-1570 had its development life ended in part due to glycol leaks at high power levels). The older Kestrel relied on pressurized water cooling and not 100% glycol, I believe, so it would have avoided this problem as did the Merlin once it switched to 70/30 water/glycol mix. (also avoiding the fire hazard of pure glycol and being more economical) The Germans never had that problem as glycol was in too short supply to use as anything but winter antifreeze, so they made do with low pressure water cooling for the Jumo 210 and early 211 and DB 601 followed by high pressure systems. I believe the V-1710 has switched to 70/30 mix at least by the time the XP-40 flew. (or at least the V-1710-33 used in production)


Another couple comments on the 'completely new engine' bit:
1. if RR passed production on to Napier, they could avoid the overhead for changing from old peregrine to new peregrine tooling as they'd be re-tooling either way. (and weren't license building Kestrels, so parts commonality there wouldn't matter either)
and
2. even with no structural changes to the engine, that same +9 lbs boost emergency rating COULD have produced significantly more power with supercharger refinements a la Merlin XX and 45. More efficient supercharger drawing less power and allowing a higher critical altitude as well.

You'd need more changes to get the thing up to 1200 hp, but 1000 hp for take-off/emergency seems realistic with supercharger refinements alone. (and a few thousand feet higher ceiling AND more power for the +6 lbs boost rating) A side bonus would be relying less on 1000 octane fuel than the Spit or Hurricane as it could still perform well at +6 lbs in a pinch. (actually, the improved efficiency -reduced charge heating- of a Hooker-modified induction system might have allowed +9 lbs with 87 octane fuel)

When merlins were available they made the Hornet which shows what was possible. Until then the RAF preferred Mosquitos.

They seemed to prefer the Typhoon, honestly, rather than investing more in Gloster or Supermarine's twins either. Gloster seems like the best bet to me given the F.9/37 was a bit underpowered with Peregrines in the first place and less tightly designed than the Whirlwind so likely easier to adapt to the Merlin with fewer modifications. (ie they might have even been able to use the existing F.9/37 airframes as early prototype conversions fro the 'Reaper' fighter project had they gotten enough funding to get it off paper -mind you the dedicated Night Fighter versions were adapted from earlier paper follow-on single-seat designs based on the F.9/37, the ministry was just less interested in twin engine fighters of any type)

http://www.warbirdsforum.com/topic/424-gloster-twin-engined-fighters/
http://img.photobucket.com/albums/v136/paul1/GlostersingleseatheavyfighterReaper.jpg

The F.9/37 was much more in line with both size and performance to the Fw 187 than the Whirlwind, and IMO had more development potential. The Whirlwind had the advantage of flying earlier and being some 30 mph faster using the Peregrines. (the Whirlwind had a better chance at displacing the Typhoon, but the Gloster Twin had a better chance at cutting in on Beaufighter and Mosquito more akin to the P-38 -or Hornet)

The problem is the air ministry was still not very interested in twin engine single-seat fighters in general (hence greater interest in turning twins into turret fighters -and turret night fighters in the Reaper's case). This fed into the lack of support for higher volume Whirlwind orders or peregrine orders back in 1939.

IMO, investing more in high performance twin engine fighters pre-war and early-war would have been a better idea than banking on 2000+ hp class engined fighters alone and if (or more likely when) those twin-engined 'backup' designed proved superior to the likes of the Typhoon, there could be a very serious and straightforward motive for canceling Sabre development and production in favor of yet more merlins.

I wonder how it might have fared as a slightly bigger plane with a pair of turbocharged Allisons. The P-38 did better than OK once the issues were worked out. I don't think it could have been done with a pair of Daimler Benzes since the war would have cut off the engine supply, and Hispano Suizas would not have given much more power than the Peregrines did. That doesn't leave a lot of possible choices in the world of the mid to late 1930's.

Why turbos, why so much bigger? Why not just the existing 8.8 supercharged versions? Again, I'd need to get the solid weight specs on the V-1710-33 (C-15), but I believe it was significantly lighter than the Merlin III (and certainly V-1710-39/F3R) and better matched the engine mount geometry of the peregrine than the Merlin did.

With the conservative Allison/USAAC ratings, you had 1040 hp for take-off and 1040 hp military at 37.2" MAP at 14,500 ft without ram. (that's only +3.6 psi boost) So you've got better power AND several thousand feet higher critical altitude than the peregrine (not too far off of the Merlin III's 1030 hp height). It made 850 hp at 20,000 ft without ram, and probably close to double the Peregrine's FTH for 880 hp with decent ram intakes employed. On the Whirlwind, you'd have 2080 hp at altitudes the Spit V was doing 1470 hp in WEP, but abusing the engines a good bit less and with older/earlier, sleeker, and significantly lighter engines.

Honestly, if Rolls Royce DID modify the Peregrine to cope with higher boost (and possibly higher RPM), it might have just ended up with similar performance and weight to the C series V-1710 anyway (let alone a hypothetical C series with the screens removed and choked supercharger intake fixed). License building the V-1710 WOULD have been technically better all around and more useful for more aircraft, the trouble comes with that likely being a slower, more troubled process than just second sourcing the Peregrine, at least if the main target is the Whirlwind. (more practical and plausible would be if Britain did what the US later did and hedged their V-12 production plans, licensing the V-1710 as a backup for the Merlin -again Ford of Britain building V-1710s would probably be a faster and more efficient route than Napier ... have Napier build more Merlins)

A V-1710-33 powered Whirlwind probably would have been a much better (and faster to develop/optimize/get into service) option than the turbo-less V-1710-33 powered Lighting Mk. I.


I really like the idea of a V-1710 C-15 powered BoB era Spitfire with that sharp Tomohawk nose. (or a Whirlwind with XP-38 style cowls, but stub exhausts)
http://img.wp.scn.ru/camms/ar/298/pics/3_123.jpg

 

[kool kitty89]

Somehow a huge number of people want to campaign for the underdog and if only a little more resources were put into a brilliant design then the war would have been "different" I dont know why so many people want the Nazis to win in the first place but from any rational view point they had way too many projects ongoing for any of them to be successful. The British, in the face of defeat, had to rationalise and the peregrine was axed along with it so was the Whirlwind. Nazi Germany in the face of defeat pursued a huge number of zany solutions. No matter what field of military endeavour they had a wild design and frequently many wild designs. There was a recent thread about "Amerika bombers" Germany had many more "designs" for bombing the USA than the USA had for bombing Europe and the USA had the resources.

I don't tend to argue that, more just that certain designs merited greater interested and were squandered. The net impact on the war for any ONE of those cases usually wouldn't be huge, but in this case it might have at very least saved the lives of a few RAF pilots and turned the tide of a few air to air skirmishes or ground attack missions that historically went much less favorably.


You can ALSO argue for just more spitfires and hurricanes instead of ANY twin or Typhoon and Tempest, which I already did address a few times in this very thread. (as far as best using pilot resources -ie not relying on more planes + pilots as just mass swarming power and cannon fodder, getting the Spitfire III into production, building more Merlin XXs, and more broadly second-sourcing the Spitfire -potentially in Canada as well- while phasing out the Hurricane sooner would all be good options up until you need a decent fighter-bomber at least)

 

[pbehn]

They seemed to prefer the Typhoon, honestly, rather than investing more in Gloster or Supermarine's twins either. Gloster seems like the best bet to me given the F.9/37 was a bit underpowered with Peregrines in the first place and less tightly designed than the Whirlwind so likely easier to adapt to the Merlin with fewer modifications. (ie they might have even been able to use the existing F.9/37 airframes as early prototype conversions fro the 'Reaper' fighter project had they gotten enough funding to get it off paper -mind you the dedicated Night Fighter versions were adapted from earlier paper follow-on single-seat designs based on the F.9/37, the ministry was just less interested in twin engine fighters of any type)

The F.9/37 was much more in line with both size and performance to the Fw 187 than the Whirlwind, and IMO had more development potential. The Whirlwind had the advantage of flying earlier and being some 30 mph faster using the Peregrines. (the Whirlwind had a better chance at displacing the Typhoon, but the Gloster Twin had a better chance at cutting in on Beaufighter and Mosquito more akin to the P-38 -or Hornet)

The problem is the air ministry was still not very interested in twin engine single-seat fighters in general (hence greater interest in turning twins into turret fighters -and turret night fighters in the Reaper's case). This fed into the lack of support for higher volume Whirlwind orders or peregrine orders back in 1939.

IMO, investing more in high performance twin engine fighters pre-war and early-war would have been a better idea than banking on 2000+ hp class engined fighters alone and if (or more likely when) those twin-engined 'backup' designed proved superior to the likes of the Typhoon, there could be a very serious and straightforward motive for canceling Sabre development and production in favor of yet more merlins.

Of course they preferred the Typhoon. A single engined fighter with 2000BHP v a twin engined fighter with 1,600BHP. And eventually they were correct, the Sea Fury was the ultimate progression of the Typhoon/Tempest/Fury as up there with the best of piston engined fighters. Any theoretical progression of a peregrine twin fighter would be eaten by a Tempest or Fury.

I cannot think of an example of a twin fighter out performing a single in the front line. There is much debate here about the P 39 .....but in Europe it was not a success.

Eric Brown loved the Hornet but did he fight in it. A twin fighter may roll well for a twin but no where near a single engined fighter. Russian fighters removed excess weight from the wings to increase roll rate.

 

[GregP]

We built more than 15,000 P-47s and the M was just a variant. But I like your idea there Shortround. The 114 or 116 for WHirrlwinds was all for the entire aircraft. With the P-47 we had an established maintenance and repair infrastructure including trained mechanics, spare parts, and supply chain. The engine was used by muiltiple aircreaft, parts were readily avaiable, and they had overhaul depots for the R-2800.

I'm not very sure about the infrastructure including the maintenance, repair, and spare parts supply chain for the Whirlwind, but since it was mostly deployed in the UK they didn't have too far to go, so perhaps it wasn't nearly as big a deal as if they deployed Whirlwinds to, say, Singapore.

It's something to think about.

If they had made 20 variants of Hellcats, each with a short life span, they still would have had the mechanics and spares and overhaul depots already there. But it could be possible the same functions were there for the Whirlwind. Since Rolls Royce was loctaed locally, maybe the factory could have functioned as the overhaul depot, though I don't know what that would do to new production or if Rolls Royce would agree to that. Interesting notion. Not sure, but it might have been possible.

I haven't heard of glaring weaknesses in the Whirlwind, just short service life followed by being taken out of production and declared "obsolete." Could be it gave very good service while in squadron service though, if true, it makes me wonder why so many references cite reliability issues with the Peregrines. Since there is little detail data, I don't know.

For US engines, we have a post-war summary of USAF depot-level overhauls including typical TBOs and typical overhaul hours, but I have yet to find a document like that for the RAF or RN.

Does anyone have a comprehensive list of awared aerial Whirlwind victories? The fact that I have read only of a few isolated victories and probables does not preclude a number of real-but-not-well-known victories in type. As I stated above, I identified 16 claims gainst the Whirlwind by the Luftwaffe and, claims being as accurate as we know them to be, that could mean they lost something like 4 to 16 with the probable real number lost to combat being somewhere around 8. I have never seen a number lost on operations or other accidents, though I have read of two accidents. 2 out of 114 to 116 isn't much of an accident history and isn't really worth quoting. The two might be all the accidents or maybe they had accidents with a lot of them ... again, I don't know.

 

[pbehn]

You can ALSO argue for just more spitfires and hurricanes instead of ANY twin or Typhoon and Tempest, which I already did address a few times in this very thread. (as far as best using pilot resources -ie not relying on more planes + pilots as just mass swarming power and cannon fodder, getting the Spitfire III into production, building more Merlin XXs, and more broadly second-sourcing the Spitfire -potentially in Canada as well- while phasing out the Hurricane sooner would all be good options up until you need a decent fighter-bomber at least)

If I was able to see into the future in 1930/40 then I would but if I could then I would know more than anyone involved in piston engine supercharger and turbo charger development and would now be seen as a genius. When the Spitfire and Hurricane were front line fighters their replacements were scheduled to be huge engined 2000BHP fighters. It is therefore obvious that no one ever considered a Merlin or Griffon could produce 2,000 BHP in service. In hindsight Napier should have been taken over and handed the Griffon to develop under Rolls Royce supervision in my opinion. The Sabre was retired as soon as the war ended but the Spitfire and the Griffon served for years after

 

[Shortround6]

I doubt that it ever will, since, if there were any, it'd be experimental only. This will bring protests from the "defenders of the faith," but the Peregrine could not run on 100 octane on a regular basis (whatever the Whirlwind Pilot's Notes say.) It was to be used in emergencies only; uprating the engine to take 100 octane 100% of the time, would have meant so many modifications, it would virtually have been a completely new engine, and that's what made Rolls-Royce baulk.

It is statements like this that raise the hackles of "defenders of the faith,".

Without a lot more explanation it makes no sense.
What is meant by "Peregrine could not run on 100 octane on a regular basis (whatever the Whirlwind Pilot's Notes say.)"
Does that mean that you could not put 100 octane fuel in the tanks and fly it for dozens of hours while never exceeding 6lbs boost (and usually running less boost and less than full rpm) without wrecking the engine? A few extra spark plug changes because of the extra lead might be called for but how does the 100 octane fuel wreck anything else?
Does it mean the pilots notes were wrong and even using 9lbs boost instead of 6lb for take-off would lead to rapid engine failure (of what kind? broken cranks? holed pistons?) or using 9lbs in "emergencies (a few minutes at a time) would do the same thing?

The Phrase uprating the engine to take 100 octane 100% of the time is also rather confusing. Most aircraft either filled the tanks (all of them) with either 87 octane or 100 octane and that is what the plane flew the mission with. The Blenheim is the only British aircraft I know of (there could well be others) that filled one set of tanks with 100 octane and another set of tanks with 87 octane for the same missions and took off using 100 octane and kept it in reserve for emergencies while cruising on the 87 octane filled tanks.
Very few aircraft (if any in the first few years of the war) ran anywhere near 100% of the time at a power level that would require 100 octane fuel. 100 octane fuel burns at the same temperature as 87 octane and has the same BTUs per gallon. The only thing in 100 octane fuel that may cause trouble is the amount of lead. This may call for different spark plugs or more frequent changing. There may or may not be a problem with the exhaust valve seats after quite a number of hours. It may or may not cause sticking of the piston rings.
Early Merlins could only use the extra power/boost that 100 octane fuel allowed for brief periods of time and in emergencies yet seemed to run for hundreds of hours on 100 octane without self destructing. A little bit later Merlins (XIIs, XXs and 45s) could cruise at 2650rpm and 7lb boost and climb for 30 minutes at 2850 and 9lbs, either of which might require 100 octane fuel. But dropping to 2600rpm and 4lbs was certainly within 87 octane limits so even these engines spent a good part of their lives running at levels that didn't require 100 octane even if that is what their tanks were filled with.
It took the Merlin quite a while to get to the point where it maxed out the capabilities of 100/130 fuel. at least 18lbs boost if not a bit above. Someone want to say what 21lbs boost needed? we Know 25lbs boost needed 100/150.

Now maybe the Peregrine was fatally flawed (or had multiple flaws) that prevented the use of even 9lb boost let alone 12lbs. Or maybe it needed a new crank, rods, crankcase, cylinder blocks,etc to get to 16-18lbs of boost. I have no idea.

But there is a world of difference between cruising at 7-10lbs of boost (running at 100 octane levels) 100% of the time and cruising at 2-4lbs boost and using the 7-12lbs boost for take-off and emergencies.

I would note, not to pick on the British, that the Allison V-1710-85 as used in a P-39Q was allowed to use 13 1/2lbs of boost in WEP, 10 1/4lbs for take off, 7 1/4lbs for military and a whopping 4 1/2lbs for max continuous (used for climb after the first 5 minutes), max cruise was small fraction under 1lb so this engine was hardly using anywhere near 100% of the capability of 100 octane fuel 100% of the time.

Now before I get accused of saying Rolls Royce was lying, IF Rolls Royce was saying that in order to make 100% use of the potential of 100 octane fuel then they could very well have been right. To make full use of 100 octane would require the engine to operate at 16-18lbs of boost and would require quite possibly a new supercharger, It might require a new carburetor to flow more air to begin with, It might have required a stronger supercharger drive to handle the greater demand for power from the supercharger, It might have required new or modified propeller reduction gear to hand the increase power. (6lbs boost is 21lb total manifold pressure, 18lbs boost is 33lbs total or a 57% increase in fuel and air going through the engine, engine power would go up in proportion minus extra power to supercharger and the loss of the lower density air due to the higher heat of compression), Then we get into the questions of if the power section (cylinder block, crankshaft,etc) can handle the increase power. And this would apply to even 5 minute bursts of power let alone 100% of the time.

Each engine is different but if you could run Bristol Mercury engines at 9lb of boost for short periods there must have been something really wrong with Peregrine if it could not. An strangely, what ever this flaw or collection of flaws was, it never gets spelled out or listed in commonly available materials (books, magazine articles, internet sites).

 

[Shortround6]

We built more than 15,000 P-47s and the M was just a variant. But I like your idea there Shortround. The 114 or 116 for WHirrlwinds was all for the entire aircraft. With the P-47 we had an established maintenance and repair infrastructure including trained mechanics, spare parts, and supply chain. The engine was used by muiltiple aircreaft, parts were readily avaiable, and they had overhaul depots for the R-2800.


I haven't heard of glaring weaknesses in the Whirlwind, just short service life followed by being taken out of production and declared "obsolete." Could be it gave very good service while in squadron service though, if true, it makes me wonder why so many references cite reliability issues with the Peregrines. Since there is little detail data, I don't know.

I think we are having a problem with term "short service life". If, as Glider posted "The RAF's rule of thumb for planning was that 50 aircraft were needed to keep one squadron operational in Europe for six months." then 114 Whirlwinds should have kept one squadron in service for just under 14 months. No 263 Squadron was in service for 22-23 months ? and No 137 squadron was in service for 18-19 months? They got roughly 3 times the "service life" the rule of thumb called for. Granted rules of thumb are just that and hardly engraved on stone tablets

The idea of checking other small production batch planes was to see how they compared. I believe the Spitfire MK VI fully equipped only two squadrons but some were issued to other units to cover spot shortages. perhaps they were replaced by two stage powered planes before they were worn out. P-47Ms equipped 3 squadrons? But as noted, mechanical problems prevented full use and the war ended before a good reading on "service life" can be had.

The two Whirlwind squadrons flew quite a number of missions per month, weather permitting, but seldom in full squadron strength. 2 and 4 plane missions were somewhat common, (the Whirlwinds often being the bait for 1-2 squadrons of escorting Spitfires). Accidents were all too common, as was damage from flak (and combinations, flak damage causing forced landing or bailout miles away from the AA guns) Perhaps 114 planes is too small a number to get a valid statistical result from but the Whirlwind did get a reputation as a "safe" plane to force land in. The engine nacelles taking up quite a bit of the impact before the fuselage/cockpit was severely damaged. Plane may have been a write off but the pilots walked away rather often.

 

[GregP]

Hi Kool Kitty,

You can reckon the V-1710 at 1,480 pounds. When we ewere building them, they were all just under 1,500 pounds with starter before adding oil for run -in. Of course, we had a run-in platform that was a Ford F-350 truck with engine mlont, radiator, oil tanka dn pump, etc. I am not sure of the all-up weight of an Allison V-1710 with radiator and oil tank ... depends on the radiator and oil tank.

My thoughts were that the Allison ws a GREAT engine down low but suffered without the turbo when things got higher than 15 - 16,000 feet ... exactly the weakness the Peregrine had. So ... the turbo would address the altitude issue. The resulting aircraft would probably have been faster than the Peregrine-powered bird but, without the turbos, would probably start to suffer in the mid-teens verus a 2-stage S/C day fighter.


I saw your post above Shortround and find the reasoning sound. We still would have the maintnenace and overhaul chain for the Spirfires, etc. that had large numbers made, but your idea of 50 fighters for one squadrom for 6 months ain't bad at all. If that was the case, the Whirlwind did OK to stay solid for about 2 years with only 116 odd aircraft. I do NOT know if they sortied at the same rate as other fighters or were sort of lightly used. Anything I say along those lines would be conjecture.

 

[Greyman]

Hmm, interesting, but no mention of addressing the problems with the slats?

The problems with the slats were only identified much later, after the type had been operational for some time. I imagine it was a case of pushing things a bit farther in combat than in initial testing.

For example, while testing the Whirlwind, the A&AEE listed a limiting dive speed of 420 mph IAS. The official Pilot's Notes list a maximum diving speed of 400 mph IAS.

The CO of 263 Squadron, however, said they had dived them to 460 mph IAS.