Shiden (George) vs F6F, P-51

Discussions on all (non-biographical) aspects of the Luftwaffe air units and general discussions on the Luftwaffe.
carolwmahs
Member
Posts: 81
Joined: 14 Oct 2005 00:09
Location: US

Post by carolwmahs » 27 Apr 2006 01:18

Great discussion and comments. Very informative.

"Aces of the Risking Sun 1937-1945" by Sakaida reports the following two combats:

On March 19, 1945, the 407th and 701st squadrons of the 343 Kokutai engaged American aircraft, including F6Fs of VBF-17. They claimed 53 Hellcats/Corsairs and 4 SB2Cs for 13 losses. CPO Katsue Kato was credited with nine victories in this engagement.

On April 16, 1945, Lt. Takashi Oshibuchi, of the 701st squadron, led a formation of N1K2-Js in support of Kikusui #3 off of Okinawa. They claimed 20 F6Fs, while losing 9 N1K2-Js.

Lt. Oshibuchi was lost in a combat on July 24, 1945. On that date 21 Shiden Kais from all three squadrons of the 343rd took off from Omura base with the head of the 701st Squadron, Lt. Takashi Oshibuchi, in the lead. They engaged a 250+ American formation, and claimed 16 enemy aircraft for the loss of six pilots, including Lt. Oshibuchi.

His last action is described here:
http://www.findarticles.com/p/articles/ ... 0188/print

Can anyone confirm the American losses with American reports?

User avatar
Michael Emrys
Member
Posts: 6002
Joined: 13 Jan 2005 18:44
Location: USA

Post by Michael Emrys » 27 Apr 2006 04:55

carolwmahs wrote:Can anyone confirm the American losses with American reports?
Not in any of these cases, but in general and on average, Japanese pilots claimed 10 for every one actually shot down.

Michael

Huck
Member
Posts: 1188
Joined: 19 Jul 2004 12:52
Location: Detroit

Post by Huck » 27 Apr 2006 05:14

Michael Emrys wrote:
carolwmahs wrote:Can anyone confirm the American losses with American reports?
Not in any of these cases, but in general and on average, Japanese pilots claimed 10 for every one actually shot down.

Michael
Hi Michael, I think this overclaiming ratio is exaggerated. Do you know on what is based on? Overclaiming rarely goes over 3 to 1, but as far as I know it never does that when it is considered the average on the entire service. USAAF+USN/Marines losses figures in Pacific are pretty well known. Do you know how many planes the Japanese claimed?

Huck
Member
Posts: 1188
Joined: 19 Jul 2004 12:52
Location: Detroit

Post by Huck » 27 Apr 2006 05:25

Pips wrote: As I said between all the above there are no significant variations. Interestingly though some books do add additional information. For example American Warplanes states that the F6F-5 could, with WEP engaged, reach speeds of 404mph. America's Hundred-Thousand supports that figure. It also states that the P-51D could, with WEP fly at 450mph.
P-51B max speed was 444 mph on WEP
P-51D max speed was 437 mph on WEP

note that P-51B was faster at high altitudes than P-51D, but slower at low altitudes

These figures are correct for factory fresh planes. Mustang max speed was very much a factor of how well the flight surfaces were maintained, especially the wings. Unfortunately, P-51 had to be serviced with people on top of the wings, which quickly deteriorated their aerodynamic qualities. In actual service max speed was usually 20 mph less than the above figures. All ww2 fighters reached smaller max speeds in service than those quoted for factory fresh planes, but Mustang suffered the most, because it relied on clean aerodynamics instead of raw power for its speed.

Huck
Member
Posts: 1188
Joined: 19 Jul 2004 12:52
Location: Detroit

Post by Huck » 27 Apr 2006 05:42

Ome_Joop wrote: However it is a fact that us test with high octane avgas had some good results with some aircrafts performance(Ki-84 going 427mph and Ki-83 over 470 mph)...but with the normal stuff the Japanese had it isn't likely but who knows!
Actually that is myth, not a fact. For a plane to have a max speed increase it requires more power at the altitude it reaches max speed. That does not happen with the boost increase that is allowed with the use of higher octane fuel, because such the boost increases, using this method, only below the critical altitude of the engine (the same happens for water injection), whereas the max speed is reached slightly above the critical altitude. A much powerful supercharger is necessary to increase the power at altitude, but the supercharger eats a lot of horsepower too (especially those meant for high altitude performance).

Without a serious modification of the engine for a larger supercharger, there can be no max speed increase (max speed at best altitude) just because the higher octane fuel allows higher boost. And certainly no Ki-84 ever flew at 470 mph (the story is about Ki-84 not Ki-83 IIRC).

User avatar
Michael Emrys
Member
Posts: 6002
Joined: 13 Jan 2005 18:44
Location: USA

Post by Michael Emrys » 27 Apr 2006 06:03

Huck wrote:
Michael Emrys wrote:
carolwmahs wrote:Can anyone confirm the American losses with American reports?
Not in any of these cases, but in general and on average, Japanese pilots claimed 10 for every one actually shot down.

Michael
Hi Michael, I think this overclaiming ratio is exaggerated. Do you know on what is based on? Overclaiming rarely goes over 3 to 1, but as far as I know it never does that when it is considered the average on the entire service. USAAF+USN/Marines losses figures in Pacific are pretty well known. Do you know how many planes the Japanese claimed?
I am depending on the accounts given in The First Team and The First Team at Guadalcanal, both by John Lundstrom. I should note that this only covers the first 14 months of the war, but to this point I am sceptical that Japanese claims became more accurate as the war wore on and their pilots became more and more dilute in quality. But I could be wrong about that.

Michael

User avatar
Pips
Member
Posts: 1230
Joined: 26 Jun 2005 08:44
Location: Canberra, ACT, Australia

Post by Pips » 27 Apr 2006 06:39

Huck wrote:
P-51B max speed was 444 mph on WEP
P-51D max speed was 437 mph on WEP
Interesting variation in speeds from America's Hundred Thousand, which is the best book around on that subject IMO. Would you mind stating where you obtained those figures Huck?

User avatar
Ome_Joop
Member
Posts: 783
Joined: 10 May 2004 15:56
Location: Noordwijk(erhout)

Post by Ome_Joop » 27 Apr 2006 19:40

Huck wrote:
Without a serious modification of the engine for a larger supercharger, there can be no max speed increase (max speed at best altitude) just because the higher octane fuel allows higher boost. And certainly no Ki-84 ever flew at 470 mph (the story is about Ki-84 not Ki-83 IIRC).
I'm 100% sure it's about the Ki-83 (that 470mph.)...and i'm also sure about the reports claiming 427mph for the Ki-84 Hayate!
Myth or truth that is something i do not know!
Maybe here is a little problem with your theory as when an engine wich required high octane, high quality fuel to perform but does not get any but gets low quality lower octane fuel (then the engine rquires) it performs less...but when it eventually gets the right fuel it can perform optimal!

TO be sure thi is a Ki-83
http://www.indianamilitary.org/FreemanA ... 200151.htm

The KI-83 was tested by both the AAF & the Navy.The AAF tested the aircraft at Freeman Field,Indiana and during the testing process they fueled it with the standard avgas used at the time which was 115/145 octane.Japanese fuel at the time the KI-83 was designed was lucky to contain 2/3 of this octane rating.The Japanese were hoping for an airspeed in excess of 400 MPH with their fuel but when tested with the high octane U.S. fuel it did indeed as recorded reach 470 MPH. I have read documents in the archives at NASM & similar reports elsewhere that appear to confirm this airspeed.If you look closely at the lineage of the KI-83 with those large radials,it would not surprise me in the least to see that aircraft attain 470 MPH. It is indeed a beautiful airframe.

User avatar
R Leonard
Member
Posts: 418
Joined: 16 Oct 2003 02:48
Location: The Old Dominion

Post by R Leonard » 27 Apr 2006 20:24

24 July 1945 - In 1354 strike sorties and 393 CAP sorties, USN air-to-air claims were 1 A6M, 2 C6N, 1 D3A, 2 J2M, 3 Ki-43, 1 Ki-46, and 6 Ki-84 for a total of 16 credits, 2 Ki-84 were reported as probables, and 2 Ki-43 were reported as damaged. USN combat losses were 17 VF/VBF, 6 VT, and 9 VB for a total of 32. Of the 32 USN aircraft lost, at least 29 were lost due to AA fire. Pilot losses were 24 (12 VF/VBF, 5 VT, and 7 VB); aircrew losses were 15 (8 VT and 7 VB). Review of strike films resulted in an estimated 40 aircraft destroyed on the ground and 80 damaged. 558 tons of bombs and 1707 HVARs were expended.

Huck
Member
Posts: 1188
Joined: 19 Jul 2004 12:52
Location: Detroit

Post by Huck » 28 Apr 2006 00:54

Ome_Joop wrote:
Huck wrote:
Without a serious modification of the engine for a larger supercharger, there can be no max speed increase (max speed at best altitude) just because the higher octane fuel allows higher boost. And certainly no Ki-84 ever flew at 470 mph (the story is about Ki-84 not Ki-83 IIRC).
I'm 100% sure it's about the Ki-83 (that 470mph.)...and i'm also sure about the reports claiming 427mph for the Ki-84 Hayate!
Myth or truth that is something i do not know!
Maybe here is a little problem with your theory as when an engine wich required high octane, high quality fuel to perform but does not get any but gets low quality lower octane fuel (then the engine rquires) it performs less...but when it eventually gets the right fuel it can perform optimal!
Hi Ome_Joop,

Let's review again the argument: I said Ki-84 (now I see it was a Ki-83) could not have a max speed increase (at best altitude) just by running on higher octane fuel. Higher octane fuel allows a boost increase only up to the critical altitude of the engine - this boost increase is large on the deck, but it gets smaller and smaller with altitude, and by the time the plane reaches the critical altitude there is no boost increase, simply because the supercharger cannot supply a higher boost (regardless of fuel octane rating). Now, the max speed is reached above critical altitude, meaning that the supercharger cannot supply higher boost to take advantage of the higher octane fuel at that altitude, which translates in no max speed increase (at best altitude) on higher octane fuel. Without making major changes to the engine and the supercharger a plane cannot be made faster just by running on higher octane fuel.
Ome_Joop wrote:TO be sure thi is a Ki-83
http://www.indianamilitary.org/FreemanA ... 200151.htm

The KI-83 was tested by both the AAF & the Navy.
Unfortunately there is a common problem for USAAF tests - nobody saw them (outside a small circle of favoured authors). So far I have not seen a single page scanned from an original USAAF max speed test. I have serious doubts about many figures quoted by those authors, some of them clearly outside the basic laws of physics.
Ome_Joop wrote:The AAF tested the aircraft at Freeman Field,Indiana and during the testing process they fueled it with the standard avgas used at the time which was 115/145 octane.Japanese fuel at the time the KI-83 was designed was lucky to contain 2/3 of this octane rating.The Japanese were hoping for an airspeed in excess of 400 MPH with their fuel but when tested with the high octane U.S. fuel it did indeed as recorded reach 470 MPH.
USAAF never used 115/145 fuel on a large scale, during the war the usage was insignificant. After the war the use of this fuel was dropped all together, and only the prospect of a war in East Asia, brought it back in use. 115/145 fuel became truly popular in mid '50, when civilian carriers asked for larger and larger airliners that could offer better seat mile costs. These airliners required powerful powerplants. Since piston aero engine development reached a plateau at that time, the only way of squeezing more power out of the available designs was to use the 115/145 fuel.
Ome_Joop wrote:I have read documents in the archives at NASM & similar reports elsewhere that appear to confirm this airspeed.If you look closely at the lineage of the KI-83 with those large radials,it would not surprise me in the least to see that aircraft attain 470 MPH. It is indeed a beautiful airframe.
What kind of documents? I would love to see some speed tests? Can you scan them?
As for Ki-83, with a good high altitude engine, I have no doubts that it could have been brought up to 450-460 mph range. But the Japanese never had good high altitude engines, nor reliable high power engines. There was intensive work done in the last months of war to replace the powerful 18 cyl radial of Ki-84 with the reliable but less powerful 14 cyl radial of Ki-100.

Purple fang
Member
Posts: 327
Joined: 05 Nov 2005 00:22
Location: utah

Post by Purple fang » 28 Apr 2006 04:15

Well, so much for Caidin then. Interesting stuff on Sakai's book & such.

User avatar
Pips
Member
Posts: 1230
Joined: 26 Jun 2005 08:44
Location: Canberra, ACT, Australia

Post by Pips » 28 Apr 2006 06:49

Yeah I have to admit I was very disappointed when I found out that most of Cainin's stuff is lacking in the historical. Still, he writes a ripping good yarn - and Samurai is certainly a very entertaining read.

carolwmahs
Member
Posts: 81
Joined: 14 Oct 2005 00:09
Location: US

Post by carolwmahs » 28 Apr 2006 19:43

R Leonard wrote:24 July 1945 - In 1354 strike sorties and 393 CAP sorties, USN air-to-air claims were 1 A6M, 2 C6N, 1 D3A, 2 J2M, 3 Ki-43, 1 Ki-46, and 6 Ki-84 for a total of 16 credits, 2 Ki-84 were reported as probables, and 2 Ki-43 were reported as damaged. USN combat losses were 17 VF/VBF, 6 VT, and 9 VB for a total of 32. Of the 32 USN aircraft lost, at least 29 were lost due to AA fire. Pilot losses were 24 (12 VF/VBF, 5 VT, and 7 VB); aircrew losses were 15 (8 VT and 7 VB). Review of strike films resulted in an estimated 40 aircraft destroyed on the ground and 80 damaged. 558 tons of bombs and 1707 HVARs were expended.
Thanks, that's fascinating - another case of claims and losses that don't quite match. Japanese pilots claimed 16 aircraft (fighters?) which matches well with USN losses, if one ignores the number attributed to flak. This report also says that there were no USN claims for Georges, althouth the 343rd says they lost six on that day. And here is one of those losses. At low altitudes, looks like an F6F-5's R-2800-10W had no trouble keeping up with a Shiden at sea level:

http://www.findarticles.com/p/articles/ ... 0188/print

American participants from VF-49 also have vivid memories of their mission on July 24, 1945. Lt. j.g. Jack Gibson recalls,

"We heard a call from some fighters ahead that they had been jumped by enemy planes. We immediately joined up to go to their aid. As we approached the planes ahead, I noticed two planes coming toward us, and I went with my wingman, Lt. j.g. George M. Williams, to investigate, Their planes had wing tanks, and as we approached, they dropped them and started to dive for the water. By now we could see that they were "Georges," and we started to close on them. Our section split and I followed one, while Lt. Williams closed in on the other. With the addition of water injection, the F6F-5 had no trouble at all in closing on the George. The Japanese pilot tried to turn inside me, but every time he started a turn, I would fire a short burst in front of him, and that would always bring him back to straight and level. When I got in effective range, my first burst knocked his wheels down. I overran him and had to pull up in a wingover to drop back on his tail. He then tried skidding turns without success. By this time, I began to get my bursts into the cockpit and his plane started to smoke. He finally fell over on one wing and went straight into the water, without burning."

Lt. Williams had this to say about the skirmish: "Lt. Gibson tally-ho'd two enemy fighters under us on the water. We made a 180-degree turn and gave chase, each taking one. I closed rapidly on my plane, which I am reasonably sure was a George. Just as I came into range of his tail, he executed a very tight turn, which I attempted to follow but in which I was not successful. Before I blacked out, I shot about a three-second burst, and I think that it killed or wounded the pilot. When I came to, I found that he was falling in a tight spiral trailing a great cloud of smoke. Just before he struck the water, another group of U.S. fighters followed him down and fired into his plane."

Huck
Member
Posts: 1188
Joined: 19 Jul 2004 12:52
Location: Detroit

Post by Huck » 29 Apr 2006 00:43

Michael Emrys wrote:
Huck wrote:
Michael Emrys wrote:
carolwmahs wrote:Can anyone confirm the American losses with American reports?
Not in any of these cases, but in general and on average, Japanese pilots claimed 10 for every one actually shot down.

Michael
Hi Michael, I think this overclaiming ratio is exaggerated. Do you know on what is based on? Overclaiming rarely goes over 3 to 1, but as far as I know it never does that when it is considered the average on the entire service. USAAF+USN/Marines losses figures in Pacific are pretty well known. Do you know how many planes the Japanese claimed?
I am depending on the accounts given in The First Team and The First Team at Guadalcanal, both by John Lundstrom. I should note that this only covers the first 14 months of the war, but to this point I am sceptical that Japanese claims became more accurate as the war wore on and their pilots became more and more dilute in quality. But I could be wrong about that.

Michael
Do you have the overall claims made by the Japanese? The overall losses (with the cause of loss) are available for both USN and USAAF flying in the area, including for the period you mentioned. If you have the Japanese claims we can compare.

User avatar
Michael Emrys
Member
Posts: 6002
Joined: 13 Jan 2005 18:44
Location: USA

Post by Michael Emrys » 29 Apr 2006 09:05

Huck wrote:Do you have the overall claims made by the Japanese? The overall losses (with the cause of loss) are available for both USN and USAAF flying in the area, including for the period you mentioned. If you have the Japanese claims we can compare.
I'll look. This may take a few days though.

Michael

Return to “Luftwaffe air units and Luftwaffe in general”