Hartmann & P-51 pilot Robert Goebel article in latest Fl

[Purple fang]

Flight Journal has a Hartmann & Goebel story. about whether Goebel shot down Hartmann.

It mentions Mustangs gross weight at 10.100 pounds & wing loading of 43.3 lb & power loading of 5.8 lb hp.

& 109 gross weight 6.950 pounds wing loading 40.1 & power loading 4.7. Superior to the P-51.

Wonder if the 109 stats are G-10 or if they legit numbers.

[Kocur]

6.950/4.7 = 1478, which means that Bf-109G6 with DB-605A at 1475PS is discussed.

10.120lbs is t/o weight of P-51D with full fuselage tank, i.e. with 85gallons of fuel in it, i.e. configuration, that was not used practically (fuselage tank was filled with less fuel, than could thoretically take due to bad handling) and most certainly no P-51 fought in that configuration. Since fuselage tank was the first to be emptied during the mission at least in greater part, even prior to drop tanks, P-51s entered fight usually with fuel in wing tanks only. In that configuration weights would be 9.610lbs for P-51D and 9.210 for P-51B/C (with 200lbs pilot ). So weightloading would be 41,2lbs/ft^2 for P-51D and 39,5lbs/ft^2 for P-51B/C and poweroadings at height where V-1650-7 produced top power (1720hp at 5750ft, and at 12.500 for V-1650-3 in earlier P-51s ) would be 5,58hp/ft^2 for P-51D and 5,35hp/ft^2.
That doesnt change fact, that powerloadings of Bf-109G/K were better in any version and due to poor high AoA characteristics of P-51 wing and slats on Bf-109 wings, the latter would enjoy advantage in low speeds, tight turns fight. OTOH P-51s were faster at all alts, with exception of Bf-109G10 and K4, which at 25.000ft. were about as fast or faster than Mustangs, but pilots of P-51s could always take the fight lower, where they held clear advantage in speeds, especially after introducing 104/150 grade fuel in summer of 1944 for 8AF fighters. And advantage in speed, especially when good team work is used, was the key to success.

[Huck]

6.950/4.7 = 1478, which means that Bf-109G6 with DB-605A at 1475PS is discussed.

10.120lbs is t/o weight of P-51D with full fuselage tank, i.e. with 85gallons of fuel in it, i.e. configuration, that was not used practically (fuselage tank was filled with less fuel, than could thoretically take due to bad handling) and most certainly no P-51 fought in that configuration. Since fuselage tank was the first to be emptied during the mission at least in greater part, even prior to drop tanks, P-51s entered fight usually with fuel in wing tanks only. In that configuration weights would be 9.610lbs for P-51D and 9.210 for P-51B/C (with 200lbs pilot ). So weightloading would be 41,2lbs/ft^2 for P-51D and 39,5lbs/ft^2 for P-51B/C and poweroadings at height where V-1650-7 produced top power (1720hp at 5750ft, and at 12.500 for V-1650-3 in earlier P-51s ) would be 5,58hp/ft^2 for P-51D and 5,35hp/ft^2.
That doesnt change fact, that powerloadings of Bf-109G/K were better in any version and due to poor high AoA characteristics of P-51 wing and slats on Bf-109 wings, the latter would enjoy advantage in low speeds, tight turns fight. OTOH P-51s were faster at all alts, with exception of Bf-109G10 and K4, which at 25.000ft. were about as fast or faster than Mustangs, but pilots of P-51s could always take the fight lower, where they held clear advantage in speeds, especially after introducing 104/150 grade fuel in summer of 1944 for 8AF fighters. And advantage in speed, especially when good team work is used, was the key to success.

Hi Kocur,

The correct loaded weight for P-51D is 10200 lb. This includes 65 US gallons in the fuselage tank and 2 wing racks which were carried almost always (they were used to install the drop tanks). This weight does not include the drop tanks.

The max speed differences between MW50 AS versions of Bf-109 and P-51 were marginal at most altitudes, including at sea level, but Bf-109 usually had the advantage. And btw 8th AF fighters never used 115/145 fuel operationally, they used it only for tests where it was found unsuitable for escort missions.

[Kocur]

On weight data

Material from: http://www.spitfireperformance.com/must ... 15342.html seems to idicate that 10.110lbs is weight including wing racks:

High speed and climb performance have been obtained on this airplane at a take-off gross weight of 9760 pounds. Performance was obtained up to an altitude of 35,000 feet in increments of 5000 feet in a clean configuration. The clean configuration included one external bomb rack on each wing.
(...)
With exception of the external load configurations all flights were made at a combat take-off weight of 9760 pounds. This includes full ammunition, full oil of 21 gallons, full wing gas load of 184 gallons and 25 gallons of gas in the fuselage tank which has a capacity of 85 gallons. The center of gravity at this loading was 27.63% MAC gear down and 27.89% MAC gear up.

10.120lbs is what I got from calculation: 9760 + (60 x 3,785 x 0,72)/0,454
60galons missing between 25 in the plane and 85 possible
("0,454" because I think in metric )


On the fuel

I agree, that 115/145oct fuel was never used by 8AF, as it was fuel available in PTO (at least for F4U-4 and 'Okinawa' P-51Ds), however 8 AF did use 100/150oct fuel, as lots of material from Spitfirperformace clearly indicate, like in: http://www.spitfireperformance.com/150g ... -fuel.html or to be more specific: http://www.spitfireperformance.com/150g ... pril45.pdf and http://www.spitfireperformance.com/150g ... arch45.pdf, not to mention links at the bottom of http://www.spitfireperformance.com/must ... gtest.html or content of some of reports here: http://www.spitfireperformance.com/must ... ports.html .

Having said that I do not recommend anyone to use above-linked site as source of knowledge of performace of Luftwaffe planes, for reasons stated here: http://www.kurfurst.bravehost.com/MW_ar ... KvsXIV.htm .

On the performance

Data from tests of P-51B/C at 67''Hg boost proves, that those planes had advantage in level speed over all Luftwaffe fighters of the time between P-51 apearance in december 1943/january 1944 and moment, when Bf-109G10 and K-4 appeared, i.e. autumn 1944. As we read in http://www.kurfurst.bravehost.com/MW_ar ... KvsXIV.htm, a even MW-50 boosted, but DB-605A powered, clean Bf-109G14/AS was capable of reaching 560kmh at SL and 680kmh at 7,5km (under fuselage bomb rack, AFAIK commonly used for 300l drop tank would cut that by few kmh), when later P-51B/C powered by low alt V-1650-7 engine with racks were making 585kmh at SL and 685kmh at 7,5km. In autumn 1944 the cleanest and the most powerfurl of later 109s, the K4 appeared (along with bit earlier and less clean G10) which depending on engine used and its boosting could develop 580kmh (early) and 596kmh (common) at SL and 710kmh to 715kmh respectively at 7,5km - I bet Kurfurst will clear whether those numbers are valid for planes with or without rack, and what was speed loss caused by it. However since June 1944 8AF fighters operated on 100/150 fuel, which provided additional power at low alts (up to 6km), which in turn let P-51B/Cs reach 611kmh at SL (with racks). P-51D would make 711kmh at 8km with racks - regardless of fuel used, as effects of boosting didnt reach that high (P-51Ds was a bit more draggy due to bubble canopy, OTOH had special flush finish on crucial surfaces of wing). Final Fw-190D9 would match or excced P-51 in speed at lower alts.
Btw. funny how both USAAF and Luftwaffe passed eachother by: the former "went low" with decision of using V-1650-7, i.e. US analogue of Merlin 66 from LF Spitfires, and Luftwaffe "went up" with late DB-605 equipped with larger DB-603 supercharger, Fw-190D and finally Ta-152H.

[Pips]

In the book "Blond Knight Of Germany" the story goes that Hartmann had just shot down a couple of Mustangs when he was bounced by 8 more. Following a rather furious and harrowing battle down to ground level he bailed out when his Bf 109's fuel lamp came on. He wasn't shot down.

Mention is also made in the book that Hartmann (indeed the Gruppe) were flying older versions of the Bf 109, but type is not specified. Here's an extract following his bail out near his field:
The air at HQ was full of bads news. Two pilts killed and a number of others wounded. Without methonal injection, the old type Bf 109 would not cut it against the Mustangs, even with expereinced pilots. Higher HQ ordered an immerdiate halt to fighter atatcks on the Americans because of these heavy losses, and the certainty that they would have become worse. immediate requests were lodged for the latest models of the Bf 109.

In all Hartmann engaged the Mustangs five times over Rumania in the spring of 1944.

Would it have been the G-6 that his Gruppe was equipped with at that time?

[Huck]

Ok, let's address some of these issues:

On weight data

Material from: http://www.spitfireperformance.com/must ... 15342.html seems to idicate that 10.110lbs is weight including wing racks:

High speed and climb performance have been obtained on this airplane at a take-off gross weight of 9760 pounds. Performance was obtained up to an altitude of 35,000 feet in increments of 5000 feet in a clean configuration. The clean configuration included one external bomb rack on each wing.
(...)
With exception of the external load configurations all flights were made at a combat take-off weight of 9760 pounds. This includes full ammunition, full oil of 21 gallons, full wing gas load of 184 gallons and 25 gallons of gas in the fuselage tank which has a capacity of 85 gallons. The center of gravity at this loading was 27.63% MAC gear down and 27.89% MAC gear up.

10.120lbs is what I got from calculation: 9760 + (60 x 3,785 x 0,72)/0,454
60galons missing between 25 in the plane and 85 possible
("0,454" because I think in metric )

We can take the loaded weight (full internal fuel and ammo load) directly from POH - this is the most reliable figure because it includes equipment that might not be there in a test flight, but it was considered necessary in a combat sortie:

[Huck]

On the fuel

I agree, that 115/145oct fuel was never used by 8AF, as it was fuel available in PTO (at least for F4U-4 and 'Okinawa' P-51Ds), however 8 AF did use 100/150oct fuel, as lots of material from Spitfirperformace clearly indicate, like in: http://www.spitfireperformance.com/150g ... -fuel.html or to be more specific: http://www.spitfireperformance.com/150g ... pril45.pdf and http://www.spitfireperformance.com/150g ... arch45.pdf, not to mention links at the bottom of http://www.spitfireperformance.com/must ... gtest.html or content of some of reports here: http://www.spitfireperformance.com/must ... ports.html .

M. Williams and N. Stirling were asked insistently to provide an USAAF document showing the actual monthly 100/150 grade fuel consumption but they never came up with one. Such a document is necessary in order to asses how spread was the use of these fuels within USAAF. The only "proof" they have is that USAAF asked for approx 20,000 tons of 100/150 grade fuel from the British. Obviously this is not an acceptable proof, because USAAF simply could have made stocks out of this type of fuel and not consume a single drop. What happened in reality was that USAAF started the tests with this fuel in early summer of 1944, and by November it was sent for operational tests down to combat units, where it proved to be unsuitable for the type of missions USAAF fighters were doing at that time (mostly escort).

Beside the USAAF 100/150 fuel consumption document M. Williams and N. Stirling were supposed to come also with a flight "Specific Engine Flight Chart", which is the typical USAAF chart that shows the throttle settings and power ratings of an engine for a specific fuel. All engines used by USAAF had one such chart for each type of fuel they were allowed to use in service. They never found one for V-1650-3/7 with 100/150 fuel which shows that this fuel was not actually aproved for service, despite the initial tests that showed that combat use is possible.

Once they come with these two pieces of evidence they have a case, otherwise it is much talk about nothing. No wonder that information about the widespread use of 100/150 fuel for the fighters of 8th AF is not to be found in history books - probably because it never happened.

[Huck]

On the performance

Data from tests of P-51B/C at 67''Hg boost proves, that those planes had advantage in level speed over all Luftwaffe fighters of the time between P-51 apearance in december 1943/january 1944 and moment, when Bf-109G10 and K-4 appeared, i.e. autumn 1944.

AFAIK Merlin powered P-51 crossed the channel in december 1943 for the first time, but it was a small scale mission. After that weather prevented any significant combat use above enemy territory. Only in March 1944 the number of Mustang sorties over Europe became significant enough that the enemy could notice its presence.

On the other side, G-10 and K-4 appeared indeed quite late, but they were not the first versions of highly boosted
Bf-109s. For high altitude work from the beginning of the G-series there were Bf-109 fitted with GM-1 boost. Without counting the GM-1 G-6 versions, the earlier ones were built in numbers higher than 600. They were used mostly for short range reconnaissance, but the important thing was that the type was there and could be used for combat if needed (it wasn't).

Then you have the operational trials with the new AS engines (fitted with larger superchargers), started in late 1943/ early 1944, the type entering service in April 1943. The MW50 boosted AM engines entered in service at about the same time. Initially most AM went to Eastern Front and AS (with a new, more aerodynamic cowling) went to Western Front. The planes used for Reich defense received the ASM engines, which combined both systems, in order to have fast climb rate for interception and excellent high altitude performance at the same time. G-6/AS with ASM engine and clean engine cowling was there in late spring, early summer to counter the new Allied planes. There was no one year gap between the dates Merlin powered Mustangs and highly boosted 109s entered in service.

As we read in http://www.kurfurst.bravehost.com/MW_ar ... KvsXIV.htm, a even MW-50 boosted, but DB-605A powered, clean Bf-109G14/AS was capable of reaching 560kmh at SL and 680kmh at 7,5km (under fuselage bomb rack, AFAIK commonly used for 300l drop tank would cut that by few kmh), when later P-51B/C powered by low alt V-1650-7 engine with racks were making 585kmh at SL and 685kmh at 7,5km.

G-14 was not exactly "clean", as most retained the old style engine cowling with the MG bulges on top. G6/AS did have the new cowling though, performance was virtually the same with that of G-10 (IIRC 580km/h at sea level, 680-690 km/h at best altitude). These speeds were very much competitive with those of Mustang. Note though that Mustang in order to reach the quoted max speed relied on the laminar flow over the wing, which required an extremely clean and well polished wing, which was impossible to maintain in field conditions (especially for Mustang of which ammunition was loaded by the crew while sitting on the wing). This is why Mustang experienced larger speed drops in service compared to factory fresh condition than other fighters (that did not use laminar flow wing).

However since June 1944 8AF fighters operated on 100/150 fuel, which provided additional power at low alts (up to 6km), which in turn let P-51B/Cs reach 611kmh at SL (with racks). P-51D would make 711kmh at 8km with racks - regardless of fuel used, as effects of boosting didnt reach that high (P-51Ds was a bit more draggy due to bubble canopy, OTOH had special flush finish on crucial surfaces of wing).

So far the 8th AF 100/150 grade fuel Mustangs are nothing else than fantasy fighters. They are good for gaming though - this is where they originated in the first place anyway. Also note that we only talked about speed, but in reality Mustang's performance was inferior to 109 in every other respect of aerial fighting, like acceleration, climb rate, turn rate and so on (and to most lightweight fighters for that matter). This is actually normal, considering that Mustang was an escort fighter not a nimble interceptor.

[Kocur]

We can take the loaded weight (full internal fuel and ammo load) directly from POH - this is the most reliable figure because it includes equipment that might not be there in a test flight, but it was considered necessary in a combat sortie

Agreed here: the missing weight to complete 10.200lbs 'limit' as the document calls it, might be well say tail warning radar or g-suit installation Or its just terminology: the document here: http://www.spitfireperformance.com/must ... -chart.jpg has 10.100lbs as P-51D "combat weight" with full ammo and full internal fuel.

On the fuel

I would not call lack of all possible documentation a decisive reason to dismiss picture, that emerges from other documents, say already mentioned: http://www.spitfireperformance.com/150g ... pril45.pdf , which was created by Technical Operations section of HQ of 8AF on 4 April 1945 and says:

"5. In as effort to reduce lead fouling, tests were conducted by this section with 150-grade fuel containing 1,5T's of ethylene dibromide. A total of about 200 hours were run by this section and three squadrons given the "Pop" fuel for acelerated service tests. The result of these service tests showed considerable reduction in lead fouling with no apparent effects otherwise. As a result, all fighter units of the Air Force were put on Pop fuel late in January 1945. About thirty days thereafter a shart increace in valve trouble were experienced with V-1650. Incpections of engines at overhaul revelaed that the hydrobromic acid was eroding the silchrome valve seats inserts to such an extent that after approximately 100 hours of operatin all the valve clearance was gone. This 100 hours is the minimul life some engines going 170 to 180 hours before this condition prevailed. There are no other deleterious effects of this fuel noted. As of 1 April 1945 fighter units of this Air Force returned to the use of 100/150 grade fuel containing 1.0 T of rthylene dibromide."

Earlier paragraphs make it clear for me, that after operational tests which were conducted until March of 1944 a decision to switch fully to 100/150 fuel was made in May and was effective since June. Problems with lead fouling of spark plugs, which meant necessity of cleaning or replacing them after 10-12hours, i.e. 2 missions, as oposed to 25hours when running at 100/130 and caused a number of abortive missions, an easy procedure was implemented to greately reduce the problems and spark plugs change after two missions was the only negative efect of using 100/150 grade after that. I cannot read the document in any other way than that all 8thAF fighter units were running on 100/150 since June 1944, after the fuel was operationally tested in some of them until March 1944. Other documentation, linked before only supports that picture, but we are all free to read it as we wish.

Lack of mentioning it in most, but not all! books related with P-51 is nothing surprising. Only very few of books on Spitfire make any mention of 100/150 fuel other than few words on V-1 chasing, despite fact, that it was used in 2nd TAF. Similarly material from Spitfireperfomace.com was the first place I saw mentioning of operatinal use of tail warning radars or g-suits in P-51s - another 'field modifications', that had no mention in most of books.

[Huck]

On the fuel

I would not call lack of all possible documentation a decisive reason to dismiss picture, that emerges from other documents, say already mentioned: http://www.spitfireperformance.com/150g ... pril45.pdf , which was created by Technical Operations section of HQ of 8AF on 4 April 1945 and says:
[...]

Indeed, it is not necessary to provide complete documentation to prove a point. However the two documents I mentioned are essential, without them this discussion is a waste of time. First document needs to provide the actual montly consumption of this fuel - the overall fuel quatity consumed by 8th AF fighters is known and we can asses how spread was the use of this type of fuel. The second document would tell us the engine settings allowed with 100/150 grade fuel - if this type of fuel was allowed to use in service only the settings already allowed for 100/130 grade fuel, then this whole discussion is useless. Remember, all the engine settings mentioned on the site you are quoting provides are from TESTS not from operations. You need the original document with the settings allowed in operations, the SEFC chart. Since this fuel was also used for V-1710 and R-2800 and no special SEFC for 100/150 grade fuel ever surfaced for them either, I am very much inclined to believe that if the fuel was in significant use, then it was used with the regular engine settings for 100/130 fuel and only because the 100/130 was not available in the quantities required (because Britain produced more 100/150 fuel than 100/130 since mid 1944, when the V-1 offensive gained momentum).

I cannot read the document in any other way than that all 8thAF fighter units were running on 100/150 since June 1944, after the fuel was operationally tested in some of them until March 1944. Other documentation, linked before only supports that picture, but we are all free to read it as we wish.

Actually no. That document says that the fuel was to be made available to all units, it does not say that from June the fighters will consume only 100/150 fuel. This is an obvious nonsense, since 8th AF fighters consumed far in excess of the 20,000 tons 100/150 fuel they got monthly from the British. And when the document says that in January 1945 all units switched to Pep fuel, it refers to 100/150 fuel supply only, because this is what this document is about. Of course that the 100/130 fuel was very much in use at that point.

[Pips]

I must be missing something here, because to me, from reading the information on 100/150 fuel usage at http://www.spitfireperformance.com it's quite clear that the 8th did use 100/150 fuel. The reports listed and detailed in this link are quite specific.
http://www.spitfireperformance.com/150g ... -fuel.html

And the following links provide information of production
http://www.spitfireperformance.com/150g ... ction.html
and consumption
http://www.spitfireperformance.com/150g ... rrels.html
http://www.spitfireperformance.com/150g ... _tons.html

[Andreas]

Regarding the P-51 use in the ETO, the following figures come from Murray 'Strategy for Defeat':

Fighters in 8th AF mid-February:

P-38J - 539
P-47D - 416
P-51B - 329

Fighters in action on day one of Operation Argument (Big Week), provided by all 17 Fighter Groups (my guess is that includes 9th AF):

P-47 - 668
P-38 - 94
P-51 - 73

Many pilots I believe were still converting to the P-51 at this stage. By the end of February three groups had received P-51Bs: 354, 357, and 363. Out of a total of 17 groups in the UK.

Once the P-51 really got into operations however, to say that the German pilots 'noticed' them is a bit of an understatement - unless it was meant they 'noticed' that the USAAF suddenly had fighter escorts over Berlin.

German single engine fighter losses by month (in percent of those present at the beginning of the month):

Jan - 30.3
Feb - 33.4
Mar - 56.4
Apr - 43
May - 50.4
June - 48.3

German fighter pilot losses (first number percent of those present; second number total):
Jan - 12.1 (292)
Feb - 17.9 (434)
Mar - 21.7 (511)
Apr - 20.1 (447)
May - 25 (578)

Total: 99% of average strength over the period lost.

The quote from Murray below shows how this made itself felt on unit level:

The war diary of the 3rd Gruppe of Jagdgeschwader Udet makes similarily depressing reading . On March 15, the Gruppe launched 20 aircraft ; 2 pilots were killed (aircraft destroyed), 2 pilots had to parachute to safety, and 2 crash landings took place . On the next day, nine aircraft scrambled; two pilots were killed, four pilots
were wounded (one severely), and one pilot parachuted to safety unhurt . On the next day, operations cost the unit one killed and two more pilots wounded (one badly) . Thus, in a three-day span, a unit with about 25 pilots had lost 5 killed and 6 wounded (2 severely).

First use in combat in the ETO:

P-51Bs finally reached squadron service in October 1943, when the USAAF 354th Fighter Group in England was equipped with the type. This assignment was something of a "snafu", however, since the 354th was part of the Ninth Air Force, which was focused on ground attack. Apparently someone in the Pentagon failed to get the word that the Merlin Mustangs were a different breed from the ground-attack Allison Mustangs.
The USAAF Eighth Air Force had begun daylight raids into Germany in early 1943, but by the fall of that year had been forced by murderous combat losses to give up such missions until long-range escort fighters became available. The Eighth desperately needed the new Mustangs, and so the 354th was immediately ordered to operate in support of Eighth Air Force long-range bomber missions, even though the group remained in the Ninth's chain of command.

P-51Bs began flying fighter sweeps over Europe in early December 1943, and were escorting bombers on raids by the middle of the month. On 13 December, Lieutenant Glenn Eagleston drew first blood with the P-51B, damaging a Messerschmitt Me-110 during a raid on Kiel. Eagleston would eventually become the top ace of the Ninth Air Force, scoring a total of 10.5 victories.

On 16 December, Lieutenant Charles Gumm scored the P-51B's first actual kill, knocking a Me-110 out of the sky over Bremen. The days of the Luftwaffe savaging unescorted bomber formations were drawing to a close.

http://www.faqs.org/docs/air/avp512.html

http://home.att.net/~jbaugher1/p51_8.html

All the best

Andreas

[Huck]

I must be missing something here, because to me, from reading the information on 100/150 fuel usage at http://www.spitfireperformance.com it's quite clear that the 8th did use 100/150 fuel. The reports listed and detailed in this link are quite specific.
http://www.spitfireperformance.com/150g ... -fuel.html

And the following links provide information of production
http://www.spitfireperformance.com/150g ... ction.html
and consumption
http://www.spitfireperformance.com/150g ... rrels.html
http://www.spitfireperformance.com/150g ... _tons.html

Yes, 8th AF did use 100/150 grade fuel, this is something I have never debated. But the questions are:

1. How spread was the use of this fuel in 8th AF service, did it go beyond operational testing? (which by the way it implies use in combat) - to answer this question they need to post the actual 100/150 fuel monthly consumption for 8th AF fighter units.


The authors of the website claim that 8th AF used for their fighters 100/150 grade fuel only since mid 1944, which is obvious nonsense. For instance, in June 1944 8th AF fighters alone consumed 51,864 tons of fuel whereas the quoted "consumption" of 100/150 fuel for 8th AF and ADGB is 25,205 tons. So obviously they were consuming 100/130 fuel also.

Now, is the quoted "consumption" in the link you gave an actual consumption in combat? The answer is no. This is a British document that only shows how much of their 100/150 stock was gone monthly and it reflects the fact that about 20,000 tons were given monthly to 8th AF. At no point the authors of the website showed the ACTUAL monthly consumption of 100/150 fuel of the 8th AF, if indeed they consumed it and not just made stocks out of it.

In fact N. Stirling himself found multiple documents saying that that 8th AF fighter units will switch to 100/150 fuel ONLY if sustainable operations were being possible on this fuel ALONE. The fact that the monthly fuel consumption of 8th AF fighter units in that period was sometimes three times higher than the 100/150 fuel quantity that Britain could supply (about 20,000 tons monthly) is another argument against their theory, beside the operational troubles this fuel brought.


2. What were the engine settings allowed if this fuel was approved for service? - to answer this question they need the SEFC charts (preferably the FOIC too) that show the performance of the engine (and plane) for the engine settings approved for a particular fuel in combat service.


ALL USAAF engines approved for service have these charts. I can post the SEFC charts for V-1710 on 91, 100, 100/130 fuels. Actually, I chased these charts for many years and now I have them for most major production engines used by USAAF on the fuels they were allowed to use. Surprisingly, I have never found a single SEFC chart for USAAF engines on 100/150 grade fuel (or maybe it is not surprising at all).