Bomber Ranges & Payloads

[Zipper730]

While I'm not sure if the USAAF/USAF had any kind of "bomber-bluebook" figures for minimum/maximum payload/range figures: I'm curious if there were any generalized trends regarding minimum payloads per category (i.e. Light, Medium, Heavy, and the short-lived Very Heavy) as well as the minimum they'd be willing to accept. Given that this would include designs as they were being developed to initial entry into service rather than ultimate-developments since that's what the specifications were calling for.

Airframes buffnut453 drgondog M MIflyer N Niceoldguy58 S Shortround6 , T tyrodtom X XBe02Drvr

 

[MIflyer]

In the USAAF, Medium Bomber, meant medium sized airplanes carrying medium sized bombloads over medium distances at medium altitudes. At the end of the WW2 the A-26 was considered to be capable of replacing both the B-25 and B-26 as well as the A-20, and that included the B-25 Gunship low altitude strafing missions. No A for Attack aircraft were envisioned to be needed, being replaced by fighters carrying bombs, and that persisted until Vietnam showed the problems of using supersonic jets for the Attack mission.

 

[Zipper730]

In the USAAF, Medium Bomber, meant medium sized airplanes carrying medium sized bombloads over medium distances at medium altitudes. At the end of the WW2 the A-26 was considered to be capable of replacing both the B-25 and B-26 as well as the A-20, and that included the B-25 Gunship low altitude strafing missions. No A for Attack aircraft were envisioned to be needed, being replaced by fighters carrying bombs, and that persisted until Vietnam showed the problems of using supersonic jets for the Attack mission.

That I'm aware of, but what I'm interested in is what the typical minimum/maximum range for payloads were typical for bombers during the Cold War period.

For example

1. Maximum Payloads: At what point would the maximum payload of a light-bomber become so large that it would no longer be considered a light-bomber and would be seen as a medium bomber? Likewise, at what point would the maximum payload of a medium-bomber become so large that it wouldn't be considered a medium-bomber and would instead be seen as a heavy-bomber?
2. Typical Ranges: At what point would the range of a light bomber with payload become so low as to be unacceptable, and at what point would said range with payload increase to the point that it would be effectively be considered a medium? Likewise, at what point would the range with payload of a medium bomber become sufficiently high that it would cease to be a medium and instead be seen as a heavy bomber?
3. Typical Payload: What typical payload to be carried over the specified range be such that it would be too small for an aircraft to be accepted as a light-bomber, and at what point would it be considered sufficiently large enough as to be labeled as a medium or heavy. This one seems specific to light-bombers only since the general load which were specified for mediums and heavies were around 10000 lb.

With the Cold War being a pretty lengthy period of time and debates as to exactly when it started: I figure, from the standpoint of aircraft design and development, it would probably be reasonable to divide it into the period before the Korean War; the Korean War; the period between the Korean War and the end of the Vietnam War, and; the period from the end of Vietnam to the end of the Cold War.

Off the bat, I could make some educated guesses...

From the period between WWII's end to the Korean War: It seemed that there were several light-bomber and medium-bomber designs that appear to establish some baseline figures

Light Bombers​

XA-43: Initial design seemed to call for a maximum payload of 8000 lb. (some sources indicate 12000 lb.) with combat radius of 1000 nm @ 35000', 600 nm @ 10000-15000' while carrying 4000 lb. load.
XB-42: While developed in WWII, it was cancelled post-War. It was built around carrying a maximum load of 8000 lb., and hauling 2000 lb. a combat radius of 2000 statute miles (though in practice that was around 1800-1900).
XA-44: Maximum payload varies from 12000 lb. to 6000 lb. depending on source. It's unclear what the requirement called for in the basic mission.
XA-45/XB-51: Initial design seemed to call for a combat radius of 800 nm at an unspecified altitude (at least I don't remember the figures) while carrying 4000 lb. and the ability to carry larger amounts of ordinance (6400 lb. internally with 2000 lb. under each wing, or 1 x Mk-4 in the weapons bay for a 10,400 lb. maximum all-out load).​

Estimates: It would appear that, with the exception of the A-26 (which, while not listed, was still operational), it would appear the desire called for a payloads ranging from 6000-12000 lb., with radius of action figures that seemed to be around 600-1000 nm while hauling around 4000 lb. of bombs.
​

... that said, I'm pretty sure that there are others who are more knowledgeable.

 

[pbehn]

In principle it is quite simple. If your runway is long enough then you take your max take off weight and trade off fuel and bomb load. That's when things get complicated, there are a whole host of possibilities and considerations.

 

[PStickney]

In the USAAF, Medium Bomber, meant medium sized airplanes carrying medium sized bombloads over medium distances at medium altitudes. At the end of the WW2 the A-26 was considered to be capable of replacing both the B-25 and B-26 as well as the A-20, and that included the B-25 Gunship low altitude strafing missions. No A for Attack aircraft were envisioned to be needed, being replaced by fighters carrying bombs, and that persisted until Vietnam showed the problems of using supersonic jets for the Attack mission.

During WW2, the U.S. Army "A-" designations weren't Attack, per se, but Light Bomber. When the USAF changed its designation system in mid-1948, the "A-" designation was assigned to Amphibian airplanes, formerly "OA-" - The A-10 Catalina, A-12 Duck, And A-16 Albatross - Most of the Amphibs were equipped as Search and Rescue aircraft, and had the 'S' pregix prepended - so "SA-10, SA-12, and SA-16.
Single Engine Light Bombers - the only ones around at the time were a few A-24 Dauntlesses used as hacks, were redesignated as "F-" for fighter, so they finished up as F-24s, and Multi Engine light bombers were designnated as "B-". The only airplane that this really affected as the Douglas A-26 Invader - all of the A-20s and Martin B-26s were long gone by then.

 

[MIflyer]

During WW2, the U.S. Army "A-" designations weren't Attack, per se, but Light Bomber.

Yeah, more or less. The USAAF evaluated the Vultee XA-41, which was rather like another AD Skyraider, but concluded that it was not a very good fighter and fighters with bombs could do the Attack job just about as well. The USAAF also considered the Beech XA-38 but did not buy it, either. Both the XA-41 and XA-38 were really designed to get down in the weeds and do some serious strafing, an approach which the A-20, A-24, A-36, B-25, and B-26 did not use, until the B-25 was modified in the Pacific as a heavy strafer, along with some of the A-20's . The strafing package was an optional add-on feature for the A-26, which could still serve as a medium altitude formation flying medium bomber.

In the ETO the USAAF recognized that the A-26 could carry a lot more ordnance than the P-47 and that at low altitudes was basically as fast as a P-47. But they found out the hard way that it was almost twice the size of a P-47 and its chances of getting hit by small arms and AAA was much greater. So you don't hear about A-26's blazing away with their twelve or fourteen forward firing .50 cal in the ETO, unlike B-25's in the Pacific. The German AA fire was much worse than the Japanese.

I read where when an A-20 unit in Europe was issued the new A-26 they were directed to fly their A-20's to an airfield in Scotland, exit the airplane without shutting down the engines, and the last guy out would advance the throttles and jump clear, letting the A-20 go off a cliff. A B-26 unit in the ETO was switched to the A-26 and insisted on keeping one of their B-26's; the A-26 made a lousy transport compared to the Marauder.

 

[Snautzer01]

read where when an A-20 unit in Europe was issued the new A-26 they were directed to fly their A-20's to an airfield in Scotland, exit the airplane without shutting down the engines, and the last guy out would advance the throttles and jump clear, letting the A-20 go off a cliff

That was before here on this site. Still not believe it. They would have been reclaimed. Or sold as scrap metal.

 

[pbehn]

That was before here on this site. Still not believe it. They would have been reclaimed. Or sold as scrap metal.

Iv been to a few ex WW2 airfields in Scotland, actually worked on one of them (Tain), none of them were on the edge of a cliff. Does a pilotless plane on the ground with throttles open go in a straight line or wander about very dangerously in circles?

 

[MIflyer]

They would have been reclaimed. Or sold as scrap metal.

Nope! One of my college professors was a US Army Lt in WW2 in the ETO. After the war his unit was told that 100 B-25's would be flown in to their location in southern Germany and they were to destroy them. He had planned to remove the radios from the bombers and use the equipment to set up a radio net for the US Forces in southern Germany. He was told he would NOT do any such thing; leave the radio equipment in the bombers. A General Officer came to see him to make sure he understood that he was not to remove the radios from the bombers. So the B-25's arrived and they wrapped primacord around the aft fuselage and the wings, blew them apart, and then buried the remains with bulldozers.

There was great fear that the massive amounts of US equipment left in Europe after the war would prevent industry from recovering because the surplus stuff would be too cheap to compete with. Even in the US, Aviation Magazine ran a editorial describing surplus as the "Sword of Damocles" that threatened the aircraft industry.

And the A-20 has become one of the rarest WW2 aircraft types. You almost never seen one, rarely even in museums. I have never heard of a foreign country flying them after the war. They did not have the range to enable them to be easily returned to the US for disposal. Admittedly, they were not much good for anything in peacetime, being too small to be auseful transport, unlike the B-25, which is one of the most common warbirds and served as a trainer and transport for the USAF, in the ANG and reserve, and in various civiliian roles such as mosquito control spraying. They seem to have gotten rid of the A-20 very very fast indeed.