Add another and even greater advantage. The USAAF of '42 had enormously better fighting doctrine and gunnery training than the RAF of '40. For an RAF pilot in the BoB, the way he had been trained to fight and fly put him at a serious disadvantage compared to the Luft. pilots. And RAF gunnery training was totally inadequate. Studies by RAF at the time showed their pilots usually opened fire at far beyond effective range. Of course, in '42 the RAF had a lot of combat experience while the USAAF was new to the game.

I can't belive your'e trumpetting US engineering quality from that era, it was notoriously sloppy. There are plenty of stories about bad tolerances and shoddy workmanship.

I'm still trying to find more info on the P-51's tail warning radar: "In addition, the -51 had TAIL WARNING RADAR! A nice touch that saved more than a few -51 pilots from early '44 on!" (Shooter, 5/26/2005, 10:50:37 PM) I haven't found much on it. But considering the "cutting edge" tube-technology SCR-720 of the Black Widow was a rather complex and bulky piece of equipment in its day, I find it hard to believe that WW2 Mustangs somehow managed to squeeze an RWR into their tails with 1940's technology.

IIRC the proximity fuze used a primitive form of radar. It would seem *something* could have been stuffed up the P-51's tail.

They did have tail warning radars, the AN/APS-13 and Monica variants. They were not mustang exlusive and only later P-51Ds had them. However, the Germans had equipment that could track the emissions. That's why they were removed from bomber command aircraft.

Did some digging today (no Saturday training, woohoo!), and found this: http://www.vectorsite.net/ttwiz5.html#m1 " [5.1] H2X / LAB / RADAR ALTIMETERS (2) & TAIL WARNING RADARS * H2S was much needed, but it was by no means perfect. In August 1943, RAF Bomber Command conducted a raid on Berlin that proved a fiasco. Five percent of the attacking force was lost and little damage was done to the city. The Rad Lab was working on targeting radars in parallel with the British, but American progress was slow. Luis Alvarez was working on an advanced concept named "Eagle", of which more will be said later, but it was a relatively long-range project. In June 1942, the Rad Lab had begun a more conservative project named "NAB (Navigation And Bombing)" that was modeled after H2S, but the small NAB team could not match the efforts of the TRE. One of the Rad Lab researchers, George Valley, who had been working on gun-laying radar, had witnessed a bomb raid while visiting London in the fall of 1942. Valley had noticed how ineffectual British anti-aircraft fire had been, and felt the best way to fight back against the Germans was not try to shoot down their bombers, but to bomb Germany. When he returned to America, he left the gun-laying project and took over the NAB group. Valley was smart, abrasive, and determined to build a targeting radar that worked. In early 1943, pressure on the Rad Lab to build a targeting radar increased. The USAAF had sent the Eighth Air Force to England to pursue precision daylight bombing, but that concept was almost a joke. While the USAAF played up the Norden optical bombsight as a miracle gadget, capable of putting a "bomb in a pickle barrel", it wasn't that good, and the region was cloudy much of the year anyway. The Sperry company had actually built a better bombsight, but the Norden company had some really good salesmen, and in fact much of what was said about the Norden bombsight was just Norden marketing "hype" that had gone into wide circulation. Valley had managed to refine the NAB S-band targeting radar to the point where it worked as well as H2S, but that wasn't good enough. The Rad Lab's efforts to build a 3 cm / 10 GHz ASV had reached the advanced test stage, however, and Valley felt that an X-band targeting radar might just be the solution. Unfortunately, everyone else was focused on the advanced Eagle radar for the targeting job. It promised much greater accuracy, and at the time the USAAF did not like the idea of carpet-bombing cities. Still, nobody was exactly sure when Eagle would be ready for combat. Rad Lab officials knew that USAAF policy could change, and so Valley was allowed to quietly continue work on X-band targeting radar as a backup plan. Valley called the X-band system "H2X", in imitation of the British H2S. Valley still feared that H2X wouldn't be accurate enough to do the job, until he realized that Army Air Force bombers bombers flew in huge formations, with the aircraft staggered horizontally and vertically to provide overlapping fields of fire for their defensive armament. The bomb pattern from such an extended formation was not going to be precise, and in principle H2X provided as much accuracy as was useful. While Eagle remained bogged down in technical difficulties, progress on H2X was rapid. Working from the S-band ASV being developed by Norman Ramsey's group, Valley's team redesigned the antenna system so that, instead of performing a 360-degree search, it scanned down and in front of the aircraft. Team members added precision ranging capabilities, and Valley himself built an analog bombsight computing system. Using it was simple: the bombsight included rotating drum that was calibrated with altitude settings, and a bombardier could rotate the drum to determine how far to lead the target at a specific altitude. The drum's position was fed back to the PPI display used by the H2X system, bringing up a circle on the display. When the circle was on target, the bombardier released the bombs. * In April 1943, there was a "radar summit" in England between officials of the Rad Lab, the TRE, and senior brass, and Lee DuBridge proposed that the Rad Lab take over targeting radar. According to DuBridge, the future should be H2X, not H2S, for both the RAF and the USAAF. The suggestion shocked the British. The USAAF had traditionally been solidly against area bombing, and now the service had reversed themselves. The British had other reasons to be annoyed with the Americans, since several Rad Lab researchers had a low opinion of H2S, the blunt Valley calling it "bucket of crap", even while the NAB effort was in worse shape. In reality, by this time the American effort was beginning to outstrip and dominate British work. Britain had been at war over two years longer than the US, and the British were increasingly exhausted. One Yank engineer visiting his counterparts at the TRE was impressed by their expertise, but observed that

Your coment that the increased weight would neccessitate higher speed is true, but only to a point. If the take off speed is ~90 or ~100 MPH as the differance between the Merlin and Griffon engined Spits was, that represents the increase in speed to make up for the increase in weight. That is why the ECONNO CRUISE SPEED DIFFERANCE between the two planes was only ~10MPH! To find the differance in speed required, find the square root of the differance ratio between the two wieghts. In the case you mention it is about 11%. However in reality it was actualy less than this number, for other reasons.

Dear AndyF; [quote]I can't belive your'e trumpetting US engineering quality from that era, it was notoriously sloppy. There are plenty of stories about bad tolerances and shoddy workmanship. [/quote] My favorite is the one about how well built RR Merlins were! They had a TBO of 150 hours, regardless of what plane they were in. While US built Packard Merlins had a TBO of 400 hours! In addition, No war time Merlin made more than 1790HP-IIRC and the post war variants maximum was 2080HP? While the Packard plant built three times as many over 2200HP Merlin engines as RR built 2050 and 2080HP units after the war, we did it durring the war and they had TBOs over 400 hours! No RR service Merlin ever made over 2080HP. The late war Allisons made 2,300HP and had TBOs over 500 hours! So much for sloppy workmanship and poor Quality control!

Dear AndyF; [quote]I can't belive your'e trumpetting US engineering quality from that era, it was notoriously sloppy. There are plenty of stories about bad tolerances and shoddy workmanship. [/quote] My favorite is the one about how well built RR Merlins were! They had a TBO of 150 hours, regardless of what plane they were in. While US built Packard Merlins had a TBO of 400 hours! firstly packard was the finest of US manufacturing look at the pre war packard cars, in a differenct class to other US firms secondly where do you get these figures from? packard merlins were built to the SAME spec as RR merlins except the carbs, alternators and valve seals(which were superior but the US would not export the raw material so RR was unable to use the same) and bearing sufaces (again due to US export restrictions) the TBO of packards was exactly the same as merlins in RAF service and I believe USAF service (have found some websites that confirm this and none that claim otherwise but if you have evidence i will be happy to conceed) the TBO of 400 hours for packards in the ONLY refence to quote this figure related to the marine packards as fitted to the elco boats and farmiles mtb/mgbs is this the reference you are using? In addition, No war time Merlin made more than 1790HP-IIRC and the post war variants maximum was 2080HP? While the Packard plant built three times as many over 2200HP Merlin engines as RR built 2050 and 2080HP units after the war, we did it durring the war and they had TBOs over 400 hours! No RR service Merlin ever made over 2080HP. The late war Allisons made 2,300HP and had TBOs over 500 hours! Rubbish the late alisons were terrible and were reknown for grenading themselves. The V-1710 became known as the "Allison time bomb" due to engine failures. Spark plug fouling from backfiring was particularly acute, and spark plugs were often swapped after a single flight. why if the alison was so good did the post war P82's use merlins despite the fact that they wernt US(the US being famous for there "not built here" attitude) cost more (RR required a $6000 license fee per engine) and that general motors owned both alison and North american? So much for sloppy workmanship and poor Quality control!

[quote]secondly where do you get these figures from? packard merlins were built to the SAME spec as RR merlins except the carbs, alternators and valve seals(which were superior but the US would not export the raw material so RR was unable to use the same) and bearing sufaces (again due to US export restrictions)[/quote] True the Allison had a reputation for problems when used at hi powers. This was traced to GM/Allisons' reluctance to fit backfire screens to the intake manifolds. This caused numerious backfires which caused all the problems you site and more. However, when Edgar Schmued, the cheif designer of the Mustang, had them fitted, all the problems dissapiered. The TBO figures came from the maintanence manuals stored at the Air Force Museum at Daton Ohio. The point was that The Allison made 2300HP and weighed less, while the Merlin made 2050. Also, that american Merlins made 2,218HP and also weighed less. The primary reason the American engines lasted longer was the type of steel in them. At that time, Britan was using so called 19 ton steel, while the Americans used 21 ton steel. The other items you sited also contributed for sure. The reason that stellite valve seats and lead babbit bearings were not shaired, was because of their strategic significance AND THEIR LIMMETED AVAILABILITY.