MOST UNDERRATED AIRCRAFT OF WWII?

Ah, no.. wrong again, Dieppe was 'bout the 1st major combat action for both Typhoon & Mustang..
Those two Typhoons must've been well 'wrung out' by then, to have had that metal fatigue failure..

& the same applied - to the admittedly much more numerous Spitfire structural-failure-in-flight - incidents,
although the 'dainty' Spit airframe was both much lighter, & more lightly stress factor capable..

On October 25, 1943, now armed with powerful 4 20mm cannons, plus 8 60-pound High Explosive Rockets, Hawker Typhoons made their first rocket attack when they struck targets near the French city of Caen. The mission, not a great success, resulted in three Typhoons lost. All told, during 1943 low-level attacks resulted in the loss of 380 Typhoons in exchange for the downing of 103 German aircraft including 52 Focke-Wulf 190s.

Rather better exchange rate then, than the pure fighter missions 'laid on' by Spitfire units during
Fighter Command's 1941/42 attempt at 'leaning forward' into France, aimed at 'attriting' LW power..

J.A.W. said:

Rather better exchange rate then, than the pure fighter missions 'laid on' by Spitfire units during
Fighter Command's 1941/42 attempt at 'leaning forward' into France, aimed at 'attriting' LW power..

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Not rather better, just slightly better, 5:1 against 3.8:1.

Jeeze.. those low-alt spec Focke's sure gave them fancy-pants high-falutin' Spits - a hellava wallopin'..

Why do I feel like I am being ignored?

Negatory Chief, we're only havin' a bit of fun.. seriously..

J.A.W. said:

Here's a 'Flight' piece on av-gas which notes the N/A racing Lion,
running on straight run gasoline, with ++TEL, for 880hp, & at good economy, too.

http://www.flightglobal.com/pdfarchive/view/1945/1945 - 1118.html

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This seems to be a bit contrary to other published information.

Lumsden claims the fuel was 25% petrol/75% benzol with 10.75cc/imp gal TEL.

Which would certainly explain the Lions ability to use 10 to 1 compression either N/A or supercharged.
Benzol having a PN number of 68 (equal to 87 octane) when running lean but a whopping PN number of over 160 when running rich.
Benzol has several interesting properties for aviation use. It weighs more than straight run gasoline. 7.34lb per US gallon vs 6lb/gal.
It has less BTUs per lb 17,300 vs 19,000 and a slightly higher latent heat of vaporization. 169 btus per pound vs 140.

So it acts about 20% better as an internal coolant, which is compounded by the fact that you have to use about 10% more to get the same power.

what is more interesting is that it freezes at 42 degrees F which makes pretty useless as an aviation fuel except as an additive for any aircraft that flies in cool weather or any not near to the ground.

I wonder what the spark plug life was with 10.75cc of TEL per gallon

If you believe you can get 880hp for one hour using 50 imp gallons of fuel then I have a nice bridge to sell you that connects Manhattan to Long Island

Well SR 6, since that 'Flight' article was based on a presentation by..
..none other than Rod Banks, Mr Schneider Trophy - hi-test fuel - himself..
I'd take it as read - over Lumsden, writing many decades later..

& since the Sabre is on record as making 900hp on +0.5lb boost for 57 gal/hr..
maybe you'd best get that B-B deed ready to hand over, gratis..

J.A.W. said:

Well SR 6, since that 'Flight' article was based on a presentation by..
..none other than Rod Banks, Mr Schneider Trophy - hi-test fuel - himself..
I'd take it as read - over Lumsden, writing many decades later..

& since the Sabre is on record as making 900hp on +0.5lb boost for 57 gal/hr..
maybe you'd best get that B-B deed ready to hand over, gratis..

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Try reading it again.
"Full information on fuel grading is given in a recent R.Ae.S. Paper by Air Commodore F. R. Banks.*"
"•"The Importance of Power Unit Development'' by Air Cdre. F. R. Banks. Journal of the R.Ae.S., April, 1945."

So the article was based on a paper written by Banks and therefore no misinterpretation or changes from the original paper could have occured?

Did the paper Banks presented even mention the fuel blend used in the Lion engine?

The Fuel blend used in the Lion was not a lot different than the blend first used by Banks in the "R"engine (a lot less lead used in the "R") and the idea that you could use straight run gasoline of around 93PN (after the addition of the lead) in a supercharged engine with 10-1 compression ratio is a little hard to believe.
This was in the early days of lead use and it took a while to realize that the use of lead did not give linier results.

By the late 30s they realized that with a straight run petrol of about 76-77 octane adding 1 cc lead raised it to about 84 octane, 2cc gave just under 87 octane, 3cc gave 87-88 and 4cc gave 90 octane. Using large amount of lead (anything over about 6cc) gave very little in return.

I do like the comparison of an engine running at lean mixture at medium/low cruise power to an engine supposedly going full tilt.
I don't suppose those racers might have throttled back at times? Like going around the turns?

On the last lap the only two planes in the air were the British ones.

J.A.W. said:

Tomo, Len Setright did have access to the Sabre's test records, & they - just as the R-2800
& the Merlin did, showed they were capable of greater outputs on test, where the engines
themselves were not subject to the constraints imposed by airframe systems limitations.

In the test cell, available cooling, fuel, & supercharger pressures were practically unlimited,
should the tester want to run the engine core to max capability,
& propeller limitations were also absent.*

Wilkinson gives the official power ratings in his book,
( parts of which are available at wwiiaircraftperformance),
- along with BMEP & fuel grade figures.

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Problem with Setright's writing is that he takes out performance numbers attained from Sabre Va from 1945 (2615 HP on +15 psi boost) and claims that the 1942-vinatge was able to replicate performance - yes, 3 years earlier. Not that it does not pass a child's brain, but RAF docs confirm just under 2200 HP, and 2400 HP by 1944 available due to improved crankshaft (this, this), and Setright does not bother to provide a trickle of evidence for hi's claim. Another problem is that he keeps telling that Sabre could do it days in a row, again without a tricke of evidence. Wilikinson states 2200 HP for the IIa, not 2600+ like Setright.
Even if RR was that evil to destroy any piece of evidence about the supposed Sabre's power figures, seems like that Air Ministry files are still alive and well, and dispute Setright's fairytales just nicely.

Tomo while only 5,000 or so Sabre's were built, you are incorrect to assert that the Hawker
fighters they powered "were too late to matter for the Allied war effort", since those British
civilians being subject to Nazi attacks by FW 190 JaBos in 1942/43 & V1 cruise missiles
in 1944 were certainly glad of the effective interception capabilities bestowed by the Sabre.

& post D-day the Typhoon units bore the brunt of RAF 2nd TAF close support, being able
to range further, faster & with twice the war-load of the Spitfires doing similar work.

The power of the Sabre enabled the Typhoon to carry a significant layer of useful
armour protection too, something the svelte Spitfires could not do.

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I will not deny that Sabre-powered A/C have done anything. However, Sabre did not take part in BoB, Battle of Atlantic, bombing of Germany proper, destruction of Luftwaffe over the same Germany, anywehere in Mediterranean, nothing in Asia, same for Pacific, nothing in the vast expanses of Eastern Europe - times and places that were deciding the outcome of the war. Sabre (and Griffon, and R-3350) were nice-to-have engines, war was decided by Merlins, Hercules, Pegasus, V-1710, M-105, M-82, AM-38, R-2800, R-1830 and even the decidely-low-tech R-1820.
V1 attacks, while indeed a threat for the civilians on the receiving end, were the effort of a defeated side to kill civilains of the winning side, and that was too little and too late to chage anything.

& when the Tempest was released from ADGB anti-V1 duties & returned to 2nd TAF,
for the offence, in the role of A2A/frontal air-superiority fighter, the Tempest shot down
every kind of long nose Focke-Wulf, late mark Bf 109, & ultra-modern turbo-jet flying..

See Caldwell's JG 26 history for evidence of how fierce were the combats which Tempest units
mounted against LW attempts to intercept Allied tactical aircraft, & mount their own A2G attacks.

Compared to the Centaurus, Griffon & Vulture, the other 'big' British aero-engines, the
Sabre was the most techically advanced of the lot, yet provided more useful war service than
the rest - put together!

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I did not attempt to trumpet the contribution of those big engines to the Allied war effort, so comparing the Sabre for them is a daming with a faint praise.

*Developing propellers to handle the Sabre's output lagged behind Sabre power capabilities,
& Hawker design boss Sid Camm accused R-R of virtual sabotage - by delaying supply of
the needed Rotol props, ( de Havilland units were proving to be problematic) & Camm
would know, because Rotol props were available for his Bristol Centaurus powered
Tempest Mk II's ( albeit the engines themselves - were scarce!) but not for the Sabre.

(Rotol was co-owned by R-R & Bristol, the letter Ro for R-R, & tol, for Bristol).

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Great.
Why such a surge to post the conspiracy theories, while not giving any facsimile of evidence to support it? Have we fallen that low?

J.A.W. said:

As matter of interest DW, have you yet seen an F6F service test showing any
more impressive speed/height graphs than achieved - by those Typhoons?
They were - very likely - preciously hand-fettled 'production' jobs..

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That's my point exactly. It's of my humble opinion that in order for it to exceed the performance of some of its contemporaries, the engine and airframe of the Typhoon had to be pushed beyond safe levels. The R-2800 could have safely operated at a higher rating, and if this occurred all aircraft powered by it would have had greater performance. But at what cost? Sometimes other factors, such as engine and airframe life, are considered just as important because you can't fly an airplane that's always broke. It's a delicate balance indeed.

And your comment about the Hellcat is well taken. But lest not forget that no other fighter aircraft of it's era had a briefer gestation and none progressed from prototype testing to squadron service within a shorter timespan. All this and with none of the tragedies that befell the Typhoon development program.

But I'm saying this not to dump on the Typhoon. I just wanted put things in the proper perspective, that's all. I'm hopeful that this doesn't turn into a p-----g contest of "my plane is better than your plane" blah blah blah....

tomo pauk said:

Why such a surge to post the conspiracy theories, while not giving any facsimile of evidence to support it? Have we fallen that low?

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I believe it is a conspiracy theory,

This was the discussion in the House of Commons. The propellers with 4 blades suffered from oil leaks requiring new seals and testing as below. It would be normal for propellers known to have a fault not to be sent until fixed and also normal IMO for Rotol not to discuss with Hawker. Since de Havilland props had problems and Hamilton standard had exactly the same problem, it just sounds like a conspiracy theory to me.


"3. When the four bladed propeller came into use it was found to leak oil (from the propeller and not from the engine) to an extent which may be unacceptable for operational use. We have, therefore. Been compelled to revert to the three bladed propeller until such time as we find a satisfactory remedy for the oil leak.

4. In reverting to the three bladed propeller it is necessary also to introduce a modification to the TEMPEST type tail plane in order to prevent recurrence of the vibration trouble. This involves fitting 10-lb., weights in the tail plane tips. There are some 70 TYPHOONS in Maintenance Units with TEMPEST type tail planes which must be modified before the are issued to the Service, and it may be modified before they are issued to the Service, and it may be the hiatus that this will cause which gave rise to the report that the serviceability and operational strength of the TYPHOON Squadrons is seriously low. Special arrangements have been made to modify these aircraft; they are being done at the rate of ten a day and all seventy should be completed by the end of this week. The situation is, therefore, not serious.

5. With regard to curing the leaking oil trouble, the Americans experienced the same thing with their MUSTANG aircraft which have four bladed Hamilton propellers very similar to the four bladed De Havilland propellers on our TYPHOONS. The Americans found a satisfactory cure by fitting a special seal and we were able to obtain from them a small number of these seals, which we are now trying out for our four bladed TYPHOON propellers. It seems likely that they will be successful, but we are unable to obtain from the Americans in this country more than the small number required for trials, as they have only sufficient to meet their own needs. Arrangements have, therefore, been made to obtain a supply from America, but these will not be available in the country before May. Other arrangements have, therefore, been made to manufacture similar seals in the country and sufficient of these should be coming available in tow or three weeks' time to meet requirements of the De Havilland propeller assembly line. I have been unable to obtain any confirmation of the report that seals have been lost in transit.

6. The TYPHOON with the TEMPEST tail and four bladed propeller has been thoroughly tested and will be satisfactory when we have overcome the leaking oil trouble. We believe that the American pattern seal will cure this trouble and trials are in progress, but they have not yet done sufficient flying time for any more definite statement than this."

Then later

April 10, 1944

"SECRETARY OF STATE.

The trials of the four bladed propeller with the seals have now been satisfactorily completed, but we shall not be completely satisfied until they have done intensive flying in the Service. The four bladed propellers fitted with the seals have already been despatched for fitting to aircraft on the Hawker production line and modified propellers will be sent for the Gloster production line early next week. The expected delivery of the modified propellers is 50 per week. Retrospective fitting to aircraft already produced will be arranged as soon as supplies of the propellers become surplus to production line commitments."

Shortround6 said:

Try reading it again.
"Full information on fuel grading is given in a recent R.Ae.S. Paper by Air Commodore F. R. Banks.*"
"•"The Importance of Power Unit Development'' by Air Cdre. F. R. Banks. Journal of the R.Ae.S., April, 1945."

So the article was based on a paper written by Banks and therefore no misinterpretation or changes from the original paper could have occured?

Did the paper Banks presented even mention the fuel blend used in the Lion engine?

The Fuel blend used in the Lion was not a lot different than the blend first used by Banks in the "R"engine (a lot less lead used in the "R") and the idea that you could use straight run gasoline of around 93PN (after the addition of the lead) in a supercharged engine with 10-1 compression ratio is a little hard to believe.
This was in the early days of lead use and it took a while to realize that the use of lead did not give linier results.

By the late 30s they realized that with a straight run petrol of about 76-77 octane adding 1 cc lead raised it to about 84 octane, 2cc gave just under 87 octane, 3cc gave 87-88 and 4cc gave 90 octane. Using large amount of lead (anything over about 6cc) gave very little in return.

I do like the comparison of an engine running at lean mixture at medium/low cruise power to an engine supposedly going full tilt.

I don't suppose those racers might have throttled back at times? Like going around the turns?
View attachment 490121
On the last lap the only two planes in the air were the British ones.

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Ok, here's the period 'Flight' article detailing the race-winning Lion:

http://www.flightglobal.com/pdfarchive/view/1928/1928 - 0310.html

Fuel 'cocktail' is stated to be "75% petrol, 25% benzol, & 0.22% TEL"
Fuel consumption is "50 gal/hr" & permissable WFO rpm is 3,300!

That beast must've roared real loud..


Also as far as fuel efficiency goes, if the volumetric efficiency of the Lion running 'unthottled'
(& ta for that race route map, it shows most of the running was straight line) was a close match
in power-to-fuel consumption level for a heavily throttled, but far higher breathing capacity Sabre,
that figures..

tomo pauk said:

Great.
Why such a surge to post the conspiracy theories, while not giving any facsimile of evidence to support it? Have we fallen that low?

Click to expand...

Relax, Tomo..

I linked Setright's piece & duly noted that it was "lurid"..

IMO, its wrong to conflate the design & specs of an engine, with the use it was put to, or the shambles of producing it.
Given the 1/2-arsed way the Brits went about it, its amazing that as many Sabres were available,
- to give the service - which they actually did.

As for "conspiracies" Tomo, Len Setright is far from the only writer to note the existence of R-R's 'dirty tricks dept',
Bill Gunston has, as have others, & indeed, it is virtually an industrial equivalent of the GRU, still in operation today,
- as recent scandals have shown.

Hawker's chief of design went on the record with his comments about Rotol props, & wwiiaircraftperformance notes
the issue, too, including a quote from Kiwi Tempest combat pilot, Ron Dennis:

"All our machines were fitted with Rotol airscrews when the maximum rpm were increased to 3,850 from 3,700,
& boost to +13 from +11, as the de Havilland airscrew could not absorb the added power & more than once shed
a blade, with somewhat detrimental effects on the engine."

September 26, 1927 – Venice, Italy (7 laps of a 50-km. course)

1. Sidney Webster 4 Supermarine S.5 N-220 46:20.3 281.656 mph

2. Oswald Worsley 6 Supermarine S.5 N-219 47:46.7 272.91

3. Frederico Guazetti 5 Macchi M.52 MM81 out lap 7 @ 257.78 mph

4. S.M. Kinkead 1 Gloster IVB N-222 out lap 6 @ 272.53 mph

5. Mario de Bernardi 2 Macchi M.52 MM80 out lap 2 @ 263.1 mph

6. Arturo Ferrarin 7 Macchi M.52 MM82 out lap 1

-- Slatter Gloster IVA N-224 reserve

-- Short Crusader N-226 w/o 9/11/27

-- Al Williams 3 Kirkham-Williams failed to arrive

DarrenW said:

That's my point exactly. It's of my humble opinion that in order for it to exceed the performance of some of its contemporaries, the engine and airframe of the Typhoon had to be pushed beyond safe levels. The R-2800 could have safely operated at a higher rating, and if this occurred all aircraft powered by it would have had greater performance. But at what cost? Sometimes other factors, such as engine and airframe life, are considered just as important because you can't fly an airplane that's always broke. It's a delicate balance indeed.

And your comment about the Hellcat is well taken. But lest not forget that no other fighter aircraft of it's era had a briefer gestation and none progressed from prototype testing to squadron service within a shorter timespan. All this and with none of the tragedies that befell the Typhoon development program.

But I'm saying this not to dump on the Typhoon. I just wanted put things in the proper perspective, that's all. I'm hopeful that this doesn't turn into a p-----g contest of "my plane is better than your plane" blah blah blah....

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Nah DW, you've got the wrong end of the stick..

The AFDU trials Typhoons were not being "pushed beyond safe limits" to show those speeds..

The quality of carefully, exactingly checked 1st 'production' units, was difficult to match with regular
production-line machines, esp' the early runs ( see P-39 saga - but in that case even the service evaluation
planes tested were well below the expected 'standard', not a 'cut above', like the AFDU Typhoons).

As for unexpected & puzzling metal fatigue problems, this was an artefact of 'pushing the envelope'
with a large, powerful, fast machine pushing into the 'ughknown' zone of 'Mach buzz' - on an 'everyday' basis.

If more Typhoon development flying had been done prior to urgent production/service entry, many of the 'bugs'
could've been sorted out by test pilots, rather than killing the hapless young fighter jocks.

Just as an aside, as most of you know this: de Havilland's propellers were Hamilton Standard designs built under license.

swampyankee said:

Just as an aside, as most of you know this: de Havilland's propellers were Hamilton Standard designs built under license.

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I read recently that on Sabre engines the Rotol props performed better than de Havillands, on high power settings the de Havilland props could shed blades.

pbehn said:

I read recently that on Sabre engines the Rotol props performed better than de Havillands, on high power settings the de Havilland props could shed blades.

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Yeah, its already duly noted, in post No 515, on this page.. Sid Camm was right.. as he usually was..