Interesting.
Did the B-26 design envision a more powerful R-2800, or a different engine?
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The design originally envisioned a more powerful engine. The -5 was all that was available when production started. The -43 was not a big improvement, so the whole B-26 program was always saddled with underpowered engines. That's a factor in aircraft development. You can't use what's not available. Then once production is in full swing, its hard to make major changes.
The B-26 involved so many untried systems that its not surprising that the early versions had a lot of issues. The Curtiss Electric prop was notorious for failing at high power.
The biggest problem was the flood of inexperienced pilots stuffed into them right out of flight school.
The 22nd BG and 28th BG, manned by crews trained prewar that flew them in action loved them. They were fast enough to outrun Zeroes, something the B-25 could not do.
The 22nd lost only a handful to fighters while flying the B-26, never more than one on a given mission, the 3rd BG flying B-25s at the same time lost five on one mission alone.
Vis the R-2800, The -5 was the initial production model of the R-2800. About 1450 were produced. The -5 production was slated to equip the B-26 program, but did not produce the promised power output. ....
The design originally envisioned a more powerful engine. The -5 was all that was available when production started. The -43 was not a big improvement, so the whole B-26 program was always saddled with underpowered engines.
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The Martin B-26 Marauder wound up as a safe medium bomber in USAAF service, so perhaps speed wasn't everything. They called it the "Baltimore Whore" due to small wings (no visible means of support) and the widow maker, but all that really happened is the pilots learned how to fly it in landing configuration so 90 mph on final didn't seem way too fast. Bad safety record at the start of service and a pretty good one by the time it was retired (loss per sortie at 0.0070 --- the BEST loss per sortie was the A-26 Invader at 0.0058, but it flew less than half of the sorties the B-26 did).
so 90 mph on final didn't seem way too fast.
Wasnt the safe landing speed more like 140mph. Imagine coming from your little 600hp Beechcraft or Cessna trainer that would land at 60mph and getting into a 4,000hp fire breathing monster like the Marauder.
William Wolf, B-26 Marauder, the Ultimate Look, is a good synopsis on the development of the B-26. Martin had proposed designs with several different engines, unsupercharged and supercharged R-2600s, unsupercharged and supercharged R-2800s and R-3350s. The Army selected the version with the unsupercharged R-2800s. This is the design that beat out the North American entry by 150 points.
Hindsight being 20/20, its clear that the B-25 turned out to be the better investment. The B-25 proved more versatile, cheaper and easier to build and maintain, easier to fly.
The A-26 was a whole generation later.
Good points, but the bolded part.
Nobody was flying military aircraft with unsupercharged engines from early 1930s on. Americans even used supercharged engines on their tanks.