Article 10954 of rec.aviation.military:
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From: jfb@usgp1.ih.att.com (Joe Baugher)
Subject: Bomber Series--North American B-25 Mitchell (8 of 32)
Message-ID: <D2MrHp.II5@ssbunews.ih.att.com>
Summary: B-25C and D strafers
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Date: Thu, 19 Jan 1995 02:13:00 GMT
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One of the more successful field modifications performed on the B-25Cs 
and Ds were conversions to heavily-armed strafers.  

The basic concept for the strafer seems to have originated with B-25 
units based in Australia.  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.  General 
Kenney felt that the development of skip-bombing techniques would give 
a much better chance of success.  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 antiarcraft 
fire from heavily-armed ships.  It was felt that heavy forward-aimed 
firepower aboard the attacking aircraft was needed to counter this 
defensive fire.  

This technique had already been tried out to a limited extent with the 
A-20 Havoc, but the A-20 had a relatively low bombload 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 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.  Fox and Gunn satisfied General Kenney that this 
was an idea worth trying, and the General gave them authorization to 
proceed.  

B-25C serial number 41-12437 was chosen for the initial tests.  Since 
in a low-level, high-speed attack the bombs would be released by the 
pilot, there was no need for a bombardier.  Consequently, the 
bombardier position was removed and replaced with a package of four 
fixed 0.50-inch machine guns with 500 rpg and aimed directly forward.  
The guns protruded from a metal plate that replaced the flat 
bomb-aiming panel.  In addition, four more fixed 0.50-inch machine 
guns were installed in individual external blisters, two on each side 
of the 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.  The plane was appropriately named "Pappy's Folly".  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.  

Trials were sufficiently impressive for General Kenney 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 of early March 1943.  USAAF A-20s, B-17s, B-25s along 
with Australian Beauforts and Beaufighters took part in coordinated 
and repeated attacks on a Japanese convoy headed from Rabaul to 
reinforce their forces based at Lae, with P-38s and P-40s flying top 
cover.  The strafer B-25s proved especially effective during this 
episode, attacking 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 preventing 
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.  

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 strafer concept was so successful that by September 1943, 175 
B-25Cs and Ds had been converted for low-level strafing by the depot 
at Townsville, Australia.  By that time, five squadrons had been so 
equipped.  

Other commands soon picked up the concept.  The 241st Bombardment 
Group based in the CBI Theatre modified a number of B-25C/D aircraft 
as strafers with various different nose gun arrangements.  They were 
used with success against railways, marshaling years, highway 
transport and storage depots.  the 41st Bombardment Group of the 7th 
Air Force in the central Pacific used strafers that were quite similar 
to those from Townsville.  

The concept even reached the Mediterranean theatre of operations, 
where 16 B-25s were modified by the 26th Air Depot Group in Egypt with 
a six-gun nose.  However, these planes were later returned to standard 
transparent-nose configuration, which indicates that the "strafer" 
concept was not widely used in the Mediterranean and European 
theatres.  

Following the development of the B-25C/D strafers mounting eight 
forward-firing guns, Major Paul Gunn developed an experimental 
installation of three additional guns to the underside of the fuselage 
between the bomb bay and the forward access hatch.  This idea proved 
to be impractical due to feed belt problems and blast effects to the 
adjacent structure.  

The North American factory came up with the idea of installing a 
fuselage-mounted module containing two 0.50-inch machine with 225 rpg.  
The unit fit into the forward access hatch.  This installation had the 
advantage in that servicing of guns and replenishment of ammunition 
could be done from inside the aircraft, but it had the disadvantage in 
forcing the crew to enter the aircraft from the aft hatch, then crawl 
over the bomb bay to get to the forward cockpit.  The unit was never 
ordered into production.  

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.  However, it was not until the advent of 
the solid-nosed B-25J that the power of the famous "Townsville" 
strafers was equalled.  

Sources:

   B-25 Mitchell: The Magnificent Medium, N. L. Avery, Phalanx, 1992.

   Medium with the Mostest--The B-25 Mitchell, Jerry Scutts,
   Air International, Vol. 44, Nos 2 and 3, 1993.

   Boston, Mitchell, and Liberator in Australian Service, Stewart
   Wilson, Aerospace Publications, 1992.

   Famous Bombers of the Second World War, William Green, Doubleday,
   1959.

   North American's Flying Gun--The Story of the B-25 From Paper
   Airplane to Legendary Bomber, Jack Dean, Wings, Vol 23 No 4, 1993.

   United States Military Aircraft Since 1909, Gordon Swanborough
   and Peter M. Bowers, Smithsonian, 1989.

   North American B-25A-G Mitchell, Aircraft in Profile, Doubleday, 
   1966.

   Jane's American Fighting Aircraft of the 20th Century, Michael J.
   H. Taylor.


Joe Baugher			  **************************************
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