Here are plans for the Douglas A-20
Boston / Havoc Bomber that I electronically scanned from my purchased copy of the November
1970 American Aircraft Modeler magazine. Because they span two or more pages, you will
need to adjust the size and alignment a bit to get halves to line up properly. You might
be able to scale up the images below is plans can no longer be purchased. Plans for this
fine model were drawn by
Mr. Björn Karlström. All copyrights (if any) are hereby acknowledged.
The AMA Plans Service offers a full-size version of plans at a very reasonable cost.
They will scale the plans any size for you. Try out my
Scale Calculator for
Model Airplane Plans.
Douglas A-20 saw widespread service in many roles throughout World
Photos by Howard Levy
An RAF Boston III in Egypt in 1943. Photo fortunately reveals
the twin swivel-mounted guns in rear cockpit, gun pod on side of nose.
MORE THAN SEVEN THOUSAND were built, yet it doesn't stand out as one of the major
types in the history of military aviation. Produced as both a bomber and a fighter, it
entered service before Pearl Harbor and remained operational to the end of the Second
World War. Yet few, aside from those who flew the Douglas A-20 or one of its many variations,
remember the type as anything more than a familiar light twin that did many jobs well,
but never did anything really spectacular.
Perhaps because of its origins the Havoc or Boston, or whatever you want to call it,
is something of an under-appreciated airplane. It began as the Douglas Model 7 A, a company
project intended to be the U.S. Army Air Corps' first twin-engined attack bomber. The
original 7 A never was completed, but the 7B flew for the first time late in 1938, at
more than 300 mph---quite a speed for bombers in those days. It was not only fast, but
it also was unusually well-armed, with eight .30-cal. machine guns in the B version and
an additional four in the solid nose of the A version.
While the airplane looked highly promising to the USAAC, the first orders came from
the French who contracted for 380, highly modified in light of what had been learned
in the Spanish Civil War. Known as the DB-7, fewer than half of those ordered were delivered
to France before that country fell to the Germans, and hardly any of those planes got
into action. By a variety of routes, a large number of them came to the Royal Air Force,
where they were pressed into service as trainers, bombers and fighters, including some
of the first radar-equipped night fighters.
Because of the desperate need for night fighters
to hold off the German He-Ills, Ju-88s and Do-217s, the British tried some novel ideas,
including trailing a bomb on a 2000-foot cable behind the Pandora version of the Havoc
I, in hopes of dragging it into low-flying- bombers. A more practical idea was the Turbinlite,
a monster searchlight grafted onto the nose of a Havoc or Boston, in place of the far
more graceful solid or clear nose. The intention was to' light up enemy aircraft so that
they could then be shot down by single-engined fighters. Before the system was fully
developed-if, indeed, it ever could have been-airborne intercept radar came into being
and the bulky light was replaced by strange collections of antennas.
the while the British were enthusiastically using the trim Douglas fighter/bomber, the
U.S. was moving ahead with its plans. The first A-20A's were ordered in July 1939, and
deliveries commenced in 1940. By 1941, as the war in Europe gained intensity and U.S.
entry neared, orders for the machine poured in from not only the USAAF and the RAF, but
also from European governments-in-exile who were fighting from British bases.
As the airplane saw more action, it was continually modified. Armament was increased,
as was the bomb load. To handle the rapidly increasing weight, the original Pratt &
Whitney R-1830 Twin Wasp engines of some 1100 hp. were replaced by Wright R-2600 Cyclones
of 1600 hp. Early problems with directional stability were corrected by enlarging the
vertical tail, thus changing its original highly tapered form to the more familiar squared-off
By 1942, substantial numbers
of A-20's were being sent to the USSR, some of them for the Soviet Navy's use as torpedo
bombers. In all, nearly 3000 went to the airplane-hungry Russians. Most of these planes
were A-20G's with heavy batteries of guns in the nose, which made them highly effective
against tanks and other hefty ground targets.
The RAF's successful use of modified bombers for night-fighting purposes did not escape
the notice of the USAAF, and about 270 A-20's were converted into what was then the Army's
heaviest fighter plane, the P-70. The first of these carried four 20-mm cannon in a special
package under the fuselage. The P-70 was used primarily to train pilots who eventually
were assigned to the North- (the rest will be scanned on request)
|A-20 - first production version for USAAF;
converted to P-70, 1 to XF-3, 2 to YF-3.
A-20A - 143 built with R-2600-3 engines.
XA-20B - 1 A-20A tested with three power turrets.
A-20B - 999 built with Wright
A-20C - 948 similar to RAF Boston III, Wright R-2600-23 engines.
A-200 - never built; would have had R-2600-7 engines.
A-20E - 17 A-20A modified with
Wright R-2600-11 engines.
XA-20F - 1 A-20A, one 37 mm cannon, two power turrets.
A-20G - 2850 built with Wright R-2600-23 engines.
A-20H - 412 as A-20G with 1700-hp
Wright R-2600-29 engines.
A-20J - 450 built as A-20G with bomber nose; 169 to RAF
- 413 built as A-20H with bomber nose.
BD-1 - several A-20A built for U.S. Navy.
BD-2 - 8 A-20B built for U.S. Navy.
OB-7 - original design of series, ordered
by French, diverted to
RAF as Boston I and II. Pratt & Whitney R-1830 Twin
OB-7A - 100 for France become RAF Havoc II. Wright R-2600
OB-7B - 300 for RAF as Boston III.
OB-7C - 48 similar 10 Boston III
for Dutch AF in exile.
DB-131 - 1 DB-7 tested by France with twin rudders.
- photo version of A-20.
|YF-3 - 2 A-20 converted to photo recon.
F-3A - 46 A-20J and A-20K converted to photo recon.
0-53 - 1489 photo recon versions
of A-20B cancelled.
XP-70 - A-20 modified to fighter with four 20 mm cannon in nose.
P-70 - 59 A-20 modified as fighters.
P-70A-1 - 39 A-20C modified as fighters.
P-70A-2 - 65 A-20G modified as fighters.
P-70B-1 - 1 A-20G modified as fighter.
P-70B-2 - 105 A-20G and A-20J modified as fighters.
Boston I - ex-French DB-7's
to RAF for training.
Boston II - ex-French DB-7's to RAF as bomber.
- 300 ex-DB-7B's to RAF.
Boston III Tutbinlite - three Boston III with 2.7 billion
light in nose.
Boston IIIA - Boston III built by Boeing for RAF.
A-20J for RAF.
Boston V-90 A-20K for RAF.
Havoc I - ex-French DB-7's 10 RAF as
Havoc 1 Turbinlite - 31 Havoc I, 2.7 billion candlepower light. Havoc II
- ex-French DB-7A's to RAF.
Havoc II Turbinlite - 39 Havoc II modified with light
Havoc III - became Havoc I "Pandora" version; 20 modified.
Havoc I (Intruder).
Douglas 7A - prototype, fighter nose, P&W R-1830 engines.
Douglas 7B - prototype, bomber nose, P&W R-1830 engines.
for larger version>
Douglas A-20 Boston / Havoc Bomber Article & Plans
Douglas A-20 Boston / Havoc Bomber Article &
for larger version>
The AMA Plans Service offers a full-size
version of many of the plans show here at a very reasonable cost. They will scale the plans any size for you. It is always
best to buy printed plans because my scanner versions often have distortions that can cause parts to fit poorly. Purchasing
plans also help to support the operation of the Academy of Model
Aeronautics - the #1 advocate for model aviation throughout the world. If the AMA no longer has this plan on file, I
will be glad to send you my higher resolution version.
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