B25 or B26, which was the better bomber?

[Greg Boeser]

Pre-war USAAF doctrine envisioned three classes of aircraft. Attack aircraft used in direct support of the ground troops classed A- for attack, heavy bombers for attacking strategic targets, and medium bombers for those "in between" targets. By the latter part of the war, with the introduction of the B-29 and the A-26, the medium bomber concept had fallen out of favor. The A-26 could carry as many as, or more bombs than, the B-25 and B-26, and the Army was seriously considering reclassifying the B-17 and B-24 as "medium".

 

[GregP]

From Table 7 in Ray Wagner's American Combat Planes in ETO:

1. B-25: 63,177 sorties, 84,980 tons bombs, 380 combat losses, 193 Enemy A/C Claimed.

2. B-26: 129,943 sorties, 169,382 tons bombs, 911 combat losses, 402 Enemy A/C Claimed.

The B-25 and B-26 both have almost exactly the same tons per sortie (1.345 and 1.304), losses per 1000 sorties (6 and 7), and enemy aircraft claimed per 1000 sorties (3.06 and 3.09). The Marauder flew twice the sorties of the B-25 and performed almost exactly the same in these categories.

From 1941 to 1945, the B-25 had 921 accidents with 233 fatal. The B-26 had 739 accidents with 223 fatal. From Statistical Digest of WWII. So, the B-26 has a slightly higher fatal accident rate. 446 B-25s wrecked. 408 B-26s wrecked. To all intents and purposes, they look almost identical statistically. The B-26 was faster, but not by a lot. It had a high accident rate at first that was cured very effectively by training. Unless you are flying from a short strip, I see little to chose between them.

In person, the B-25 flies VERY well. I have no experience at all with the B-26 other than seeing Kermit's plane, and have never seen their flying characteristics compared. I lean toward the R-2800 but also lean toward the B-25 if only from familiarity. The one we have (Planes of Fame) has been very reliable (it just got back from an uneventful trip to Italy ... except for the bill for petrol), especially considering that WWII ended 73 years ago. Our 75+ year old R-2600 engines run GREAT and so do our R-2800s.

 

[Zipper730]

Pre-war USAAF doctrine envisioned three classes of aircraft. Attack aircraft used in direct support of the ground troops classed A- for attack, heavy bombers for attacking strategic targets, and medium bombers for those "in between" targets.

I didn't know that, I figured light-bomber was for the in-between part since the attack category would have taken up some of the light-bomber category too.

The A-26 could carry as many as, or more bombs than, the B-25 and B-26, and the Army was seriously considering reclassifying the B-17 and B-24 as "medium".

Yeah and the development of the B-47 would put an aircraft in the same size range as the B-29 as a medium bomber. The B-29's and B-50's would eventually be reclassified as mediums from Very Heavy at some point in time.

From Table 7 in Ray Wagner's American Combat Planes in ETO:

1. B-25: 63,177 sorties, 84,980 tons bombs, 380 combat losses, 193 Enemy A/C Claimed.

2. B-26: 129,943 sorties, 169,382 tons bombs, 911 combat losses, 402 Enemy A/C Claimed.

The B-25 and B-26 both have almost exactly the same tons per sortie (1.345 and 1.304), losses per 1000 sorties (6 and 7), and enemy aircraft claimed per 1000 sorties (3.06 and 3.09). The Marauder flew twice the sorties of the B-25 and performed almost exactly the same in these categories.

Yeah, honestly -- there's a part of me that wonders if there'd have been any difference if we basically built another 4000-5000 and either scrapped the B-26 or stopped the production line early.

 

[Jugman]

The sources I have seen have the B-24 being faster and having longer range than the B-17 with the same payload. See, for example, B17 vs B24, and B-17 vs. B-24 | The Veterans Breakfast Club | Creating communities of listening

This doesn't necessarily mean it was a better combat aircraft, at the B-17 was reputedly both less difficult to fly and more robust.

Context! Context! Context! It's all about context. At most altitudes the B-17 had greater range than the B-24 because its engines had somewhat better fuel consumption. Appendix 2 of this range comparison illustrates this quite nicely. At higher weights the B-17 did not have enough power above 20,000ft to maintain an optimal cruise profile.

Purely from a range and endurance stand point the B-17 would have been the better patrol aircraft.

 

[Greg Boeser]

But the extra bomb bay of the B-24 meant it could carry auxiliary tanks while still carrying a decent payload.

 

[Jugman]

But the extra bomb bay of the B-24 meant it could carry auxiliary tanks while still carrying a decent payload.

The bomb bays for both aircraft had the same bomb capacity and their bomb bay tanks cut it in half. In any event the addition of extra wing tanks in both aircraft made bomb bay tanks unnecessary.

 

[GrauGeist]

The B-17 and B-24 also used "Tokyo Tanks", which were removable tanks fitted into the wings, outboard of the engines.
The cells were self-sealing and connected to the fuel system via valving. The drawbacks to these tanks were that it required removing wing panels to install/remove, which was labor intensive. Also, they had no fuel gauge.

Here's a diagram of the B-17F's complete fuel storage (the B-17G was identical).
It also includes both the Tokyo Tank arrangement (find tanks numbered 1 through 9, port & starboard) and the bomb-bay tanks.

 

[Zipper730]

But the extra bomb bay of the B-24 meant it could carry auxiliary tanks while still carrying a decent payload.

But it would have been way better with one huge bomb-bay: Why use two bomb-bays when one HUGE bay will work?

 

[Reluctant Poster]

The FEAF did not want the A-26, preferring to keep the B-25. The attached memo discusses the battle over plans to convert all medium bomber units to the A-26. Note that the A-20 and the B-26 went out of production well before the war ended.

 

[GreenKnight121]

I assume you are talking about the Doolittle raid but the Navy later on did more experiments with the B-25 or known to the navy as the PBJ. As you can see by the pictures below from the book Squadron Signal B-25 in action book.

View attachment 352612

Doolittle would have appreciated that option.

What Dolittle would really have loved was the other half of that test aboard Shangri-La.

The PBJ-1H was also equipped with catapult bridle hooks - and made a catapulted launch as well.

http://steeljawscribe.com/2007/10/05/flightdeck-friday-more-oddities

Lieutenant Commander Syd Bottomley, who had earlier served as XO of VB-3 at the Battle of Midway and then succeeded Max Leslie as squadron CO when Leslie fleeted up to CAG-3, was assigned to the Ship Experimental Unit of the Naval Aircraft Factory at Mustin Field, Philadelphia in the fall of 1943.

To further prove their points of hook location and swivel, Bottomley sought and received permission for BuAer to include their PBJ-1H in catapult and shipboard handling tests. An SBD tail hook assembly (the SBD was considered to have the most reliable tailhook arrangement) was installed on the PBJ and it was readied for further testing. In land based tests conducted at USCGAS Cape May an unexpected problem appeared: with full-flight engagement of the arresting gear, the single pilot's seat lock would disengage and let the pilot and seat slide forward onto the yoke. This was a big surprise the first time it happened and certainly not a happy event for Bottomley. As a solution, a steel strap was welded to the top of the seat from the bulkhead behind the pilot to keep the seat in place.

On November 15, 1944, three aircraft were successfully tested for arrested landings and catapult launches aboard USS Shangri-La. Charlie Lane successfully demonstrated the results of relocating the swivel arrestor hook on the F7F. Bob Elder put an arrestor hook equipped P-51 through its paces.

And then it was Bottomley's turn in the PBJ. Bottomley told the story:

" . . . it was amazing how easily the PBJ swung into the groove and picked up a wire. The ensuing catapult shot was a breeze, as was the next landing. Then the PBJ was struck below for handling tests on the hangar deck. The main wheels had been designed to turn sideways to ease the plane into tight spots, so BuAer and AirLant staff observers were all over, in and under the PBJ.

"Everything had gone so well it was determined no further shipboard tests were necessary and I taxied into position on the catapult. I had planned to take just the plane captain, Koffel, and Chief Photo Mate Hicks back to Philadelphia direct from the ship. However, Lieutenant Jim Daniels, the SEU catapult officer, talked me into letting him ride over the bottom hatch below the cockpit with Koffel. Chief Hicks sat in the cannoneer seat to my right.

"When the catapult fired, the yoke flew out of my hands as the pilot's seat slid back into the bulkhead, doubling up the steel jury straps that were only designed to keep the seat from moving forward. Some observer on the ship had apparently tried to adjust the pilot seat position and the latch had never re-positioned in its track slot. There we were, airborne off the bow with no one near the controls. But thank God for Jim Daniels! Jim had played tackle for the Georgia Tech Rose Bowl team immortalized by "Wrong Way" Right. With one shove of his mighty arm that seat went back along the tracks into position where I could grab the yoke and reach the wheels-up lever. We then departed for NAS Norfolk, landing an hour later none the worse for our experience."

 

[Reluctant Poster]

This memo discusses the efficiency of various USAAF bombers in the Pacific. As you might expect the B-29 wins hands down with the A-26 a distant second.

 

[Shortround6]

Part of the Reason the B-26 was built the way it was and used the engines it did was timing.
It was only about 1-2 months behind the B-25 and over 500 had been built before the 5th F4U was built and 1000 had been built before the first F6F.
The two stage engines simply were not available (as a production item) when the plane was designed and built.
Adding the two stage engines at a later date is a lot harder than it appears.

or google any cut away of a B-26. The wing spars (two) are very near the front of the wing and near the back (which complicates adding Fowler flaps at a later date)
The wing root is full of fuel tank/s between the spars and the outer wing panels contain fuel tanks from the nacelle outwards.
The wing leading edge is full of control runs (cable or pushrod?) .

The P-61 used two stage engines with all intakes in the wing leading edge but the P-61 actually used a bigger wing than the B-26 (even the later ones) and had the spars further in from the leading and trailing edges, it also held less fuel than a B-26 wing.

Please take a good look at a P-61C or F-15 which used turbo R-2800s and see the extra lump under each engine nacelle and the two added scoops at the 5 and 7 o'clock positions on the cowl. You may not be able to swap a turbo for a two stage supercharger without additional intercooling or plain cooling airflow.

Had they been willing to delay manufacture of the B-26 then the more advanced engines might have been used. But it would have required quite a few changes to the original B-26 structure.

AS for size/drag. please note that on the F6F cowl and the three scoops at the bottom the outer two ONLY feed the intercoolers. the center one takes care of both the oil cooler and the combustion intake air. You need between 2 and 3 times the air flow of combustion air for the intercoolers to work properly. Late B-26 air intakes are over sized to allow for easy fit of air filters for dusty conditions so don't use them for comparison

 

[rsgwynn1]

The proposed B-27 Macgyver never got off the ground, but it solved the difference problem by welding the front half of a B-25 to the rear half of a B-27. It was held together by duct tape, rubber bands, office paper, and paper clips and got a huge power assist from two propane-tank-assisted jets on the tail assembly. Luckily the war ended before its designer and his crew could get killed.

 

[tomo pauk]

Now that's what I call contribution.

 

[MIflyer]

Before the end of WWII the USAAF proceeded to phase out all of the twin engined trainers and replace them with B-25's. The TB-25 served as a twin engined trainer and general purpose hack transport with the USAAF and USAF into the late 1950's.

The B-25H originally was supposed to use R-2800 engines but the first prototype of that installation pulled its wings off while doing a high speed pass over Mines Field.

The NAA B-28 used R-2800 engines, was designed for high altitude operations, and looked a lot like the B-26.

The reason the B-26 units in the ETO had such a low loss rate while flying at the 15,000 ft altitude where German flak was so deadly was that the units studied what the RAF had found out and when over enemy territory constantly changed directions every five minutes or so, less time than the Germans required to set up a flak ambush. This may have been a factor in the B-26 having both a Navigator and a Bombardier, while the B-25 had one man do both.

 

[Greg Boeser]

B-26 crews in the ETO generally carried a crew of six. Pilot, co-pilot, bombardier/navigator, engineer, radio operator, gunner. Lead ships for group, squadron, and flight would carry both a dedicated bombardier and navigator, usually the best trained and most experienced in the group. The bombardier/navigators were often referred to as "toggliers" as their job was to toggle off their bombs on cue with the lead ship's drop. One thing that ETO based B-26 units did was train to fly in very tight formation, presenting a smaller target for flak, which coupled with frequent jinking while in enemy airspace, made them very difficult to hit. There were instances in which a lead plane in a box of six might be hit and catch fire, engulfing the slot plane behind it in flsmes.

 

[MIflyer]

The book I read by a B-26 navigator said that they had both a bombardier and a navigator. The bombardier was also trained as a navigator, so after takeopff the co-pilot would silde back his seat and let the Nav go into the nose, where he and the bombardier would crouch (there being no seats in the nose) and argue about where they were for the whole mission. Also, the nose bubble gun could not be fired without removing the Nordon bomb sight, and on the only occasion in which they were ordered to strafe the target after bombing it, the bombardier pulled the Nordon loose and handed it to the Navigator to hold as he grabbed the .50 cal..

 

[Greg Boeser]

Which book was that? I haven't seen that one yet. Always interested in adding to my B-26 library.

 

[MIflyer]

The book is called "Flying the B-26 Marauder Over Europe" by Carl H Moore. It seems to be available on Amazon and ebay. It came out something like 30 yrs ago. Sorry about missipels; Firefox wonlt let me correct anything this morning

I do recall another book that was not about the B-26 but a B-26 pilot described an interesting incident.

The B-26's in the ETO mainly did not use their package guns for anything, since strafing was quite rare. But one day a B-26 was on the outer edge of a formation and a BF-109 made a firing pass. The B-26 pilot dove after the 109, fired the package guns, and blew the fighter out of the air. He them pulled back up into formation and heard "Nice shooting!" over the radio.

 

[Greg Boeser]

Add that to my book want list for Christmas.