Hope this is of interest
Your posts are always of the very greatest of interest
Danny.
A dive bomber needs a long dive, as near vertical as possible, to give the accuracy which you buy it for in the first place. It is not - and cannot be - "a low altitude attack fighter"
I think the Colonel had in mind, what in modern day speak would be called, a "multi role" aircraft. The A-36 did in fact perform in all three roles - bomber escort, dive bombing and ground attack. It also had some 100 "kills".
The US Army got some, called it the A-24, but did not do much with them
AFAIK
They considered them too slow, lacking defensive armament, and unable to operate without fighter escort, so looked at the Vengeance instead. Did you ever come across either of the A-36 squadrons in India
Danny?
Having worked extensively in configuration control, I can only express great pity for the maintainers of early Mustangs. One would be lucky to find two identical airplanes, and spare parts must be a nightmare.
NAA Chief Engineer Lee Atwood had the following to say about production,
“Dutch had put a lot of effort and talent into increasing the efficiency of airplane production. Even at high wartime rates of production, parts were made in batches, and it was most unusual to have a machine tool dedicated to making one part, or even to one operation. Many tools, especially for sheet metal parts, were ‘soft’ tooling-using Masonite, plywood, or low-temperature casting materials, rather than tool steel, and were much cheaper if not as durable. However, for the purpose, they were adequate and were made much more quickly and were adaptable to the inevitable changes that came along. Dutch made many contributions to the cutting, forming, and stretch—fitting techniques, but his greatest improvement came from rationalization of assembly and installation processes.
“It was common practice to finish the structural elements, wing, fuselage, etc., and then begin installation of equipment-electrical, hydraulic, armament, instruments, and other items—in the nearly completed structure. In large airplanes, with plenty of access room, this worked reasonably well with few bottlenecks, but in smaller planes, such as fighters and trainers, the final assembly stage was crowded, hectic, and inefficient. Starting with the T-6 series, Dutch required that fuselage and wing structures remain open in sort of half-shell condition until all wiring, tubing, and permanent equipment installations were made and that they be inspected and tested before joining into complete structures. This naturally required that the engineering design provide for this construction process—so it became part of house practice in all models."
This somewhat revolutionary view of production would go a long way toward speeding production of the first Mustangs. In comparison, the Supermarine Spitfire was a very complex fighter to build, and was not really suited for the style of mass—production techniques envisioned by Henry Ford——the creator of the concept. In some ways, the Mustang went together was like a very large model airplane kit, making the type ideally suited for construction in very large numbers.
Dutch Kindelberger put the matter into more perspective when during late 1942 he wrote, “At no time prior to the late 1930s did the quantity of planes in a single contract justify even moderately high tooling costs. Even when the first orders exceeding 500 planes were placed by the British and French in 1939, and by our own government under the National Defense program in 1940, tooling costs had to be held down, simply because it proved necessary to make changes in design to meet changing needs. When NAA passed the 1,000 mark on Harvard trainers for the British and Empire air forces in March 1941, it did not mean that we had produced 1,000 identical planes. Actually, there were 2,500 change drawings made after the first Harvard was produced, and among those 1,000 trainers there were actually more than 25 different models, each varying from the others in some major or minor detail of construction. Yet, NAA shattered every then—existing production record in providing these 1,000 Harvard trainers, emphasizing the fact that we were geared to handle changes without disrupting production. The reason, of course, was flexible tooling.
“When the American aircraft industry was finally given the green light for all—out aircraft production, there was much cost for freezing designs. Then, if ever, existed an opportunity for real production tooling in the aircraft industry. Enthusiasm was high for an air war in which America could utilize its mass production techniques. Many ardent, if misinformed, prophets counted the days until the war would be won.
“Fortunately for the nation’s ultimate welfare, the high commands of our Army and Navy were not stampeded by the popular cry for mass production of frozen designs. Instead, through their respective procurement groups, the Army and Navy called upon the aircraft industry to increase production as rapidly as possible without disrupting the tooling flexibility, which is today paying dividends on the fighting fronts.
“If you have 50,000 parts to make, you can spend $45,000 (90 percent) on tooling, $4,500 (9 percent) on labor, and $500 (1 percent) on material waste and come up with a cost per part of only $1. However, reduce the quantity of parts to 500, and your cost per part becomes $100. Under this condition, it is wise to spend $100 (20 percent) on tooling, $395 (79 percent) on labor, and $5 (1 percent) on material waste. Efficiency suffers, but the cost is down to normal, and tooling and production time are reduced to only a fraction of the time required to build a $45,000 tool and knock out 500 parts.
“In wartime, this formula becomes more complicated. Among the additional factors which must be considered are: Allowable production time in the light of war needs, tooling time, production time, space required by tool, skill required with tool, and adaptability of tool to wartime allocation and flow of materials.
“Even assuming that 10,000 planes of a frozen design could be built, it would be of little wartime utility to be engaged in tooling for the duration. The war is being fought today and can be won or lost with the equipment we shipped to the fighting fronts yesterday. Ask any military leader to choose between 100 combat airplanes in the air today and 10,000 combat planes corroding on the ground when the war is over!"
The Mustang was produced in 11 main variants, with 29 sub types. The B-5-NA sub variant introduced some 67 changes for example.