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Sat Jun 14, 2008 11:03 pm

Searching the internet, I see the NMUSAF has a great selection of "factsheets" on various airplanes - including each model in the B-25 series. Each sheet has a few photos that can be downloaded and several were high resolution.

Now here's where I learned something. I'm used to the slim carb air intakes and the boxy TB-25 post-war style, but I'd never noticed the "Not in Stock" style. Looking through the B-25A-D factsheets, I see that now.

Also, see this shot of the Doolittle B-25Bs:

http://www.doolittleraider.com/images/h53421.jpg

Of course, the transition must have occurred sometime during the C & D model run, as there are some photos of these with the more slim intakes. The NMUSAF B-25B factsheet includes shots of their "Doolittle" airplane, which, if course, is a modified D ... and, nowadays, you can't see the cowls due to the canvas engine covers. But an old photo shows that particular D with slim intakes and Clayton exhausts. And, for you real detail hounds, the NMUSAF loaded the photo in reverse - looking at the copilot's side as if it's the pilot's ... a project for mustangdriver to fix ...

Ken

Re: B-25D Gunship Mods

Fri Feb 01, 2013 9:51 am

Some great stuff in this thread. My magazine is doing a feature on "The Royce Raid" it'll include those early mods by "Pappy" gun and how the raid, because of it's timing it's overshadowed by the Doolittle raid.

If ANYONE has hi-res images of field modded B-25s in their collections PLEASE contact me. - guy.aceto@weiderhistorygroup.com

Sooner is great.

Thanks loads for this forum
Guy

Re: B-25D Gunship Mods

Sat Feb 02, 2013 12:07 am

Most credit Pappy Gunn, But I credit Jack Fox for making it work.
Here is the story
A civilian Technical Representative for North American Aviation Corporation named Jack Fox experimented with gun installations in the nose of B-25 Mitchell aircraft used by the U.S. Fifth Air Force during World War Two. Jack Fox also accompanied the early model B-25 Mitchells into combat with the 3rd Attack Group and often flew actual combat missions in New Guinea to see how his field modifications fared. Thus he earned the respect of all - engineers, pilots and ground crew.
This story provides a detailed history of these efforts and how they contributed to winning World War Two.
Medium-altitude bombing attacks against Japanese shipping had not been all that successful, since most of the bombs tended to miss their targets. This was due partly to the fact that medium and high-altitude bombing was subject to inherent errors in accuracy due to uncertain winds and to difficulties in sighting, but also due to the fact that ships could often see the bombs coming their way and had enough time to get out of their path. In skip bombing, the pilot approaches the target ship at a speed of 200 mph and at an altitude no higher than 250 feet off the water. Releasing the bomb at that height or lower caused it to skip off the water and slam into the ship just above the waterline, giving a much better chance of a hit than conventional bombing from medium altitudes. However, this technique required a low-level straight-on approach against intense anti-aircraft fire from heavily-armed ships. It was felt that heavy forward-aimed firepower aboard the attacking aircraft was needed to counter this defensive fire.
The skip bombing technique had already been tried out to a limited extent with the A-20 Havoc, but the A-20 had a relatively low bomb load and a limited range. In addition, there was a severe shortage of A-20s in Australia and in the entire South Pacific due to the priority of Lend-Lease deliveries to the Soviet Union. The B-25 Mitchell was slower than the A-20 Havoc, but had greater range. The idea of modifying the B-25 as a "strafer" seems to have originated with NAA field service representative Jack Fox and Major Paul I. "Pappy" Gunn of the 3rd Bombardment Group.
The strafer modification to the B-25's began at Eagle Farm Airfield in Brisbane Australia in about Nov/Dec 1942. B-25C serial number 41-12437 was chosen for the initial tests. Jack Fox and Major Paul I. "Pappy" Gunn started experimenting with eliminating the bombardier position and putting more guns in the nose. They came up with several different combinations and configurations while experimenting in the field. One had four 50 caliber machine guns, one had a 20mm canon and three 50's, and one even had a 75mm canon in the nose. Major "Pappy" Gunn had the ingenuity and NAA field service representative Jack Fox the diligence to make it all work. The plane was appropriately named "Pappy's Folly". Jack Fox often flew actual combat missions in New Guinea to see how his field modifications fared.
NAA field representative Jack Fox at the Townsville Air Depot in Queensland, Australia, modified B-25Cs and B-25Ds to accommodate a typical fit of four 12.7 millimeter machine guns in the nose and two or four such weapons in blister packages below the cockpit. Since in a low-level, high-speed attack the bombs would be released by the pilot, there was no need for a bombardier. The bombardier position was removed and replaced with a package of four 50 caliber (12.7 mm) machine guns with 500 rounds per gun in the nose and aimed directly forward. The guns protruded from a metal plate that replaced the flat bomb-aiming panel. Two 50 caliber (12.7 mm) machine guns in blister packs were installed on both sides of the forward fuselage. Blast protection from the fuselage blister guns was achieved by using blast tubes on the gun barrels and by mounting large sheet metal plates on the fuselage sides that covered the entire blast area. Other modifications included three Douglas A-20A fragmentation bomb racks that were installed in the right side of the bomb bay leaving the space on the left side for bombs or fuel. Lastly, they removed the remotely operated ventral turret. The modified B-25 strafers could carry 60 parachute fragmentation bombs together with six 100-pound (45.4 kg) general purpose bombs in the bomb bay. In the first tests, the fuselage guns were found to be too far forward for the center of gravity, and were later moved further aft. The entire 90th Bomb Squadron, of the 3rd Bomb Group was in operation with strafer B-25's by the beginning of February 1943. A few strafer B-25's modified at Brisbane during April-May 1943, carried, in addition to the 50 caliber four gun nose battery, a single fixed 20 mm cannon in the forward firing position at about the 4 o'clock position as you look at a strafer nose. They were not very effective due to the problem of synchronizing their firing trajectory with the nose guns, and other problems, and were soon removed and the position faired over. The B-25 strafer with eight .50-caliber guns firing forward, twin fifties in the top turret and single fifties at the two waist positions had sufficient destructive power to "dissolve" a ship's superstructure. Trials were sufficiently impressive to order more strafer conversions. By the end of February 1943, twelve strafers were completed by the Eagle Farms operation in Australia and assigned to the 90th Squadron.
The strafer concept proved particularly effective during the Battle of the Bismarck Sea in early March 1943. USAAF A-20s, B-17s, and B-25s took part in coordinated and repeated attacks on a Japanese convoy headed from Rabaul to reinforce their forces based at Lae. The strafer B-25s proved especially effective during this episode. They assaulted the convoy from nearly masthead altitude using skip-bombing techniques to attack the ships broadside. The withering fire from the eight forward-firing 0.50-inch machine guns prevented any effective return fire. Out of the original convoy of eight destroyers and eight cargo vessels that had departed Rabaul, all the transports and four of the destroyers were sunk or beached. The B-25C/D strafers achieved a 43 percent hit ratio. In other missions against land targets, these B-25s were rigged with bomb bay cages that contained up to 100, 23-pound parachute fragmentation bombs. These bombs were released in great numbers to attack airfield dispersals and flak batteries. The 3rd Bombardment Group specialized in low-level attacks throughout the war, earning it the unofficial title, "The Grim Reapers."
By the time the modification program was shut down in September 1943, 175 B-25Cs and Ds had been modified. The leaders of the USAAF's Thirteenth Air Force in the Solomon Islands were also impressed and they began modifying their B-25Cs and Ds into strafers. They were followed by the Seventh Air Force in the central Pacific, the Ninth Air Force in Egypt, and the Tenth Air Force in India and Burma. The success of the "strafer" modifications to the B-25C/D led to the B-25G, which was a dedicated factory-built strafer that was succeeded by the more efficient B-25H.
The accomplishments of Technical Representative Jack Fox should not be overlooked. He put his life on the line to test his work. It is thanks to people like him that we won World War Two. This story is dedicated to all the Technical Representatives who have served and to those who continue to support those who serve.

Re: B-25D Gunship Mods

Sat Feb 02, 2013 8:38 am

they also tried .30 caliber machineguns in the landing light bays in the outter wing panels but dropped that concept when cracks were found that attacked the structural integretity of the outter wing panels due to the vibration caused by the firing of the guns

those guys :drink3: were incredible weren't they

Re:

Sat Feb 02, 2013 9:29 am

Matt Gunsch wrote:I wish someone would make a movie about Pappy Gunn, think of all the B-25 mods he came up with.


Hollywood is an industry based on fear and formula.
Pappy Gunn (and Jack Fox) is too obscure of a figure--no Hollywood producer would touch a bio on this guy.
The first thing they would ask you after you pitched the story would be "Who?"

A film about a B-25 pilot and his unit in SWP is probably a more realistic proposition. Pappy and Jack would be a side story (if mentioned at all).

Been hoping for a B-25 movie for a long time.

TM

Re: Re:

Sat Feb 02, 2013 9:35 am

TonyM wrote:
Matt Gunsch wrote:I wish someone would make a movie about Pappy Gunn, think of all the B-25 mods he came up with.


Hollywood is an industry based on fear and formula.
Pappy Gunn (and Jack Fox) is too obscure of a figure--no Hollywood producer would touch a bio on this guy.
The first thing they would ask you after you pitched the story would be "Who?"

A film about a B-25 pilot and his unit in SWP is probably a more realistic proposition. Pappy and Jack would be a side story (if mentioned at all).

Been hoping for a B-25 movie for a long time.



TM


you are not solo in that thought process....every once in a while I start into withdrawal and must watch the great motion picture Catch 22 pop2 just to get my fix 8) , then follow up with whatever video I can find on youtube :shock:

Re: B-25D Gunship Mods

Sat Feb 02, 2013 10:02 am

Jack and his creation, courtesy of my good friend Jack Heyn! As Jack would say, the forgotten heros of the forgotten 5th. My dad was on one of the first missions flown by Pappy with the cannon.. Found a couple Japanese tin cans in Bogdan Bay near Cape Gloucester.. Pappy "bounced" a couple rounds off one with little effect. He did destroy a Japanese transport that was trying to land though...


Image


And the ships they hit that day.. July 28, 43'

Image

Image

Image


and even got a little press coverage ( abet a little wrong)

Image

Re: B-25D Gunship Mods

Sat Feb 02, 2013 3:51 pm

gary1954 wrote:they also tried .30 caliber machineguns in the landing light bays in the outter wing panels but dropped that concept when cracks were found that attacked the structural integretity of the outter wing panels due to the vibration caused by the firing of the guns

When I started reading this thread from the beginning, I was already wondering how many guns you could stick in an airplane. I though of it because of the configuration of the blister packs on either side of the B-25 nose:
Jack Cook wrote:Image

The later models had them spaced out so that there was a single gun in each blister, with 1 of the 2 on each side higher on the fuselage:
Image
Anyway, it had me wondering that since the 2 single packs were more spaced out, could you have fitted 2 twin packs on either side instead? That would be 4 guns on either side rather than 2 - giving a total of 18 forward firing 50s with the 8 in the nose and 2 in the top turret locked forward. Assuming that there was only 1 gun each mounted in the landing light bays, you could get up to 20 guns firing forward! :shock: (I know it would be impractical but I couldn't help but wonder.)

While I'm on the topic, anyone know the record for most forward firing guns on an aircraft? Here's one honorable mention:
Wikipedia wrote:Another P-38L was modified after the war as a "super strafer," with eight .50 in (12.7 mm) machine guns in the nose and a pod under each wing with two .50 in (12.7 mm) guns, for a total of 12 machine guns. Nothing came of this conversion, either.
Someone please tell me there are pictures of this.

Hemiman wrote:My dad was on one of the first missions flown by Pappy with the cannon.. Found a couple Japanese tin cans in Bogdan Bay near Cape Gloucester.. Pappy "bounced" a couple rounds off one with little effect. He did destroy a Japanese transport that was trying to land though...

You don't mean with the 75, right? :shock:

Either way, it does make me think of a quick fact I read somewhere once. Apparently, at one point during the war a U-boat got really lucky and took down a Soviet bomber/patrol aircraft with its 88mm deck gun! :shock:

EDIT (05/03/13): I found the source for the deck gun shoot down claim: The Deck guns - Techologogies - uboat.net. It can be found below the picture in the "Examples of use" section. It occurred on 10 October 1944 and was performed by U-242. I must have assumed the bomber/patrol aircraft detail seeing as the website does not mention what type of aircraft it was.
Last edited by Noha307 on Tue Mar 05, 2013 5:15 pm, edited 1 time in total.

Re: B-25D Gunship Mods

Sat Feb 02, 2013 4:04 pm

Noha307 wrote:
gary1954 wrote:they also tried .30 caliber machineguns in the landing light bays in the outter wing panels but dropped that concept when cracks were found that attacked the structural integretity of the outter wing panels due to the vibration caused by the firing of the guns

When I started reading this thread from the beginning, I was already wondering how many guns you could stick in an airplane. I though of it because of the configuration of the blister packs on either side of the B-25 nose:
Jack Cook wrote:Image

The later models had them spaced out so that there was a single gun in each blister, with 1 of the 2 on each side higher on the fuselage:
Image
Anyway, it had me wondering that since the 2 single packs were more spaced out, could you have fitted 2 twin packs on either side instead? That would be 4 guns on either side rather than 2 - giving a total of 18 forward firing 50s with the 8 in the nose and 2 in the top turret locked forward. Assuming that there was only 1 gun each mounted in the landing light bays, you could get up to 20 guns firing forward! :shock: (I know it would be impractical but I couldn't help but wonder.)

While I'm on the topic, anyone know the record for most forward firing guns on an aircraft? Here's one honorable mention:
Wikipedia wrote:Another P-38L was modified after the war as a "super strafer," with eight .50 in (12.7 mm) machine guns in the nose and a pod under each wing with two .50 in (12.7 mm) guns, for a total of 12 machine guns. Nothing came of this conversion, either.
Someone please tell me there are pictures of this.

Hemiman wrote:My dad was on one of the first missions flown by Pappy with the cannon.. Found a couple Japanese tin cans in Bogdan Bay near Cape Gloucester.. Pappy "bounced" a couple rounds off one with little effect. He did destroy a Japanese transport that was trying to land though...

You don't mean with the 75, right? :shock:

Either way, it does make me think of a quick fact I read somewhere once. Apparently, at one point during the war a U-boat got really lucky and took down a Soviet bomber/patrol aircraft with its 88mm deck gun! :shock:



B-25J Attack Version, eight in the nose, to on each side of the cockpit, thats 12, spin the dorsal turret to fire forward and you have 14 .50s firing forward. Imagine had much more deadly she'd have been with a cannon from an A-10 or a mini-gun from a Cobra pop2

Re: B-25D Gunship Mods

Sat Feb 02, 2013 5:55 pm

gary1954 wrote:B-25J Attack Version, eight in the nose, to on each side of the cockpit, thats 12, spin the dorsal turret to fire forward and you have 14 .50s firing forward. Imagine had much more deadly she'd have been with a cannon from an A-10 or a mini-gun from a Cobra pop2


While the side pack guns could be fitted along with the solid 8-gun nose, I've read it was rare that they did. There were actually a lot of problems with vibration and blast damage from the side guns and a lot of crews (and probably more crew chiefs!) didn't care a lot for them.

Another common modification was to remove the 75mm cannon used in the G and H and replace it with 2 .50 cals. The 75 was considered too slow firing and overkill for many of the coastal junks, trawlers and landing craft that were typical targets for the B-25s.

Re: B-25D Gunship Mods

Sat Feb 02, 2013 7:28 pm

There was a TU-2 weapons package that put eighty-eight (88) PPSh-41 smg's together for strafing.

Thant would be approximately 80,000 rounds per minute. 16.17 lbs/sec,

But only about 6 seconds worth.
Attachments
88ppsh.jpg

Re: B-25D Gunship Mods

Sat Feb 02, 2013 8:15 pm

shrike wrote:There was a TU-2 weapons package that put eighty-eight (88) PPSh-41 smg's together for strafing.

Thant would be approximately 80,000 rounds per minute. 16.17 lbs/sec,

But only about 6 seconds worth.

Wasn't there a simular proposal put forward by MARTIN for the B-57?

A guy I used to work with told tales of a photo lab (back when photoshop was a King Photo booth in a parking lot, kids ask your parents) tweeked large photo that hung in an office he worked out of while in the USAF in Viet Nam that depicted a 747 making an apparent low pass over the countryside with a minigun firing out of each of the cabin windows :minigun: :minigun: :minigun: :minigun: :minigun:

Re: B-25D Gunship Mods

Sat Feb 02, 2013 9:21 pm

"You don't mean with the 75, right? "

Yep.. Jock Henebry hit the plane first then Pappy finished with a "Bang" Dad's favorite pilot said the debris was blown better than 200 feet in the air.. Jim swears they flew under the pilot who was still strapped in his seat!

Re: B-25D Gunship Mods

Mon Feb 04, 2013 11:46 am

shrike wrote:There was a TU-2 weapons package that put eighty-eight (88) PPSh-41 smg's together for strafing.

Thant would be approximately 80,000 rounds per minute. 16.17 lbs/sec,

But only about 6 seconds worth.

That's right, I forgot about that one. I never really knew the details though. I had seen the picture of the guns retracted in the bomb bay before, but I hadn't seen the one where they were extended. Honestly, I didn't even know that set up allowed them to lower the guns like in the second photo. A certain quote from another recent thread comes to mind when I look at these photos...
Wildchild wrote:Oh Russia...

Re: B-25D Gunship Mods

Mon Feb 04, 2013 4:24 pm

Noha307 wrote:
shrike wrote:There was a TU-2 weapons package that put eighty-eight (88) PPSh-41 smg's together for strafing.

Thant would be approximately 80,000 rounds per minute. 16.17 lbs/sec,

But only about 6 seconds worth.

That's right, I forgot about that one. I never really knew the details though. I had seen the picture of the guns retracted in the bomb bay before, but I hadn't seen the one where they were extended. Honestly, I didn't even know that set up allowed them to lower the guns like in the second photo. A certain quote from another recent thread comes to mind when I look at these photos...
Wildchild wrote:Oh Russia...



I don't believe that they do retract at all. I'm pretty sure the 'raft' they are mounted on is just removable for service and reloading.
I think the MO was to open the bomb bay doors, let'er rip, clean up the airplane and fly back to base and swap it out for another one.

I imagine you's have to consider all of the shell casings as part of the 'weight of fire' calculations too<G>
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