FS2002/2004 Douglas O-35/B-7
I was not aware of this airplane until very recently; there are only a couple of photo's and not much info available on the internet. I was interested because of its looks, the gull wing is quite graceful and the overall impression is of a 2H pencil with wings. Fortunately, Bob's Air Docs had a drawing by Paul Westbury made in 1971 that is of excellent quality. I used this drawing for backgrounds in FSDS2.24.This very early bomber also featured a DC-3 type retracting landing gear.
I created this model with FSDSv2.024 and compiled it directly into FS2004. I then copied it back into FS2002. It works in both sims, although there is a difference in pitch trim which seems to be a common difference between the 2 sims. It is painted for the 31st Bombardment Squadron assigned to March Field in California in about 1933. I am not sure if the shade of blue is "politically correct" but I like it, and more important, my wife likes it; nuff said. The model features the usual moving parts, a pilot and gunner figure, nav and landing lights and has a bit of a specular color shine. There was one substantial description of the O-35/B-7 on the net which I have included at the bottom of this file.

INSTALLATION: Unzip DougB7.zip into a temporary folder. Copy the folder Douglas B-7 into the simulator Aircraft folder. Open the "gauges" folder and copy the contents into the simulator Gauges folder. This model will show in the aircraft selection list under Douglas as the DougB7.

PANEL: I could find no documentation for a real panel so I included a vintage style panel of my own. The vintage gauges are by Phil Profili.

SOUND: I aliased the c182 sound, but add a sound file of your choice. If you are using FS2004, the DH-88 sound file is very appropriate.

LEGAL: This project is released as freeware. You may modify it, repaint it, etc., upload to another website as long as it is not for profit. You need my written permission to use any of these files for commercial purposes; otherwise just give me credit for the original design. This airplane should not hurt your computer but I am not responsible if it causes problems.

Enjoy! Paul Clawson

Email: p.pandj@verizon.net

O-35/B-7 Notes The following info was obtained from: home.att.net/~jbaugher2/b7.html

Douglas B-7Douglas B-7
Last revised July 11, 1999

In early 1930, the Douglas aircraft company submitted a proposal to the Army for
a twin-engined observation plane. It was designed to compete with the Fokker
XO-27, two examples of which had been ordered in June of 1929.
The Douglas proposal was for a monoplane with high-mounted braced gull wings and
metal construction with corrugated duralumin covering on the fuselage and tail
surfaces. It was to be powered by a pair of Curtiss Conqueror twelve-cylinder
liquid-cooled Vee engines that were housed in nacelles attached underneath the
wing by a series of struts. The main undercarriage members retracted backwards
into the engine nacelles, but the lower portion of the wheels remained exposed
in order to reduce the amount of damage in the event of a wheels-up landing.
Four crew members were to be carried--an observer/gunner in an open cockpit in
the nose firing a single 0.30-inch machine gun, a pilot in an open cockpit just
ahead of the wing, a gunner in an open dorsal cockpit in the rear fuselage
firing a single 0.30-inch machine gun, and a radio operator in an enclosed cabin
admidships.
On March 26, 1930, the Army ordered two example of the Douglas proposal. One was
designated XO-35 (30-227) and the other XO-36 (30-228). The two planes were to
be almost identical to each other, with the primary difference being that the
XO-35 had two geared 600 hp Curtiss GIV-1570C (military designation V-1570-29)
Conquerors driving three-bladed propellers and the XO-36 had two direct-drive
600 hp Curtiss V-1570C (military designation V-1570-23) Conquerors driving
two-bladed propellers. Since the propellers of the XO-36 were of smaller
diameter than those of the XO-35, the engine nacelles of the XO-36 were to be
mounted 8 inches closer to the aircraft centerline.
The performance of the XO-35/36 promised to greatly exceed that of the lumbering
Keystone biplanes that were at that time the standard USAAC light bombers.
Consequently, the Army decided to have the XO-36 completed as a light bomber
rather than as an observation plane. It was assigned the designation XB-7, and
was to have been equipped with racks for 1200 pounds of bombs underneath the
fuselage. At the same time, the Army ordered that the second Fokker XO-27 be
completed as a light bomber under the designation XB-8.
The XO-35 flew for the first time in the spring of 1931. It was delivered to
Wright Field on October 24, 1931. The XB-7 was delivered to Wright Field in July
of 1932. The XB-7 had racks for 1200 pounds of bombs underneath the fuselage.
Both planes had corrugated metal fuselage and tail coverings. The tailplane was
supported by wire bracing.
On August 22, 1931, the USAAC ordered seven Y1B-7 bombers and five Y1O-35s.
Serials were 32-308/314 and 32-315/319 respectively. These were delivered
between August and November of 1932. Both the bomber and observation models
standardized on geared versions of the Conqueror engine. The Y1B-7 was powered
by a pair of 640 hp V-1570-33 or 675 hp V-1570-52 engines, whereas the Y1O-35
was powered by a pair of 650 hp V-1570-39 or 675 hp V-1570-53 engines.
The service-test aircraft differed from the prototypes in having smooth rather
than corrugated metal covering on their fuselages and in having fabric covering
for their movable tail surfaces. The length was increased from 45 feet to 45
feet 11 inches, and an adjustable tab was added to the rudder. The tailplane was
now supported by metal struts rather than by wires. Fuel capacity was increased
by 116 US gallons. The fuel distribution system was modified and the engine
controls and the oil cooler were improved.
Shortly afterward, the Army lost interest in twin-engined observation aircraft
and no production examples of the Y1O-35 were ordered. The Y1B-7 was rapidly
made obsolete by advances in bomber technology (such as the Martin B-10), and no
production was ordered for this version either.
The seven Y1B-7s were assigned to the 11th and 31st Bombardment Squadrons at
March Field in California, becoming the Army's first monoplane bomber to enter
service. They were later redesignated B-7. One was lost in a crash during its
first year of operation. The five Y1O-35s (later redesignated O-35) entered
service with Observation Squadrons at Crissy and Mitchel Fields.
On February 9, 1934, President Franklin Roosevelt cancelled all air mail
contracts with civilian carriers and ordered the Army Air Corps to take over the
flying of the air mail. The Army had few aircraft that ware suitable for this
mission, but a motley collection of bombers, transports, observation planes, and
even fighters were assembled. Among the planes assigned to air mail duty were
the XO-35, the five O-35s, and the six surviving B-7s. These planes were
assigned the mission of carrying the air mail from Cheyenne, Wyoming to the
Pacific coast, a particular dangerous route since it involved flying over a lot
of mountains. By June 1, 1934, when the Army Air Corps finally stopped flying
the air mail, four B-7s had been lost in accidents. However, the XO-35 prototype
and all five of the O-35s survived the air mail duty.
Following the completion of the air mail duty, the O-35/B-7s which had survived
returned to more conventional military roles, and they remained flying until
nearly the end of the 1930s, despite their obsolescence. The XO-35 was surveyed
on October 28, 1938, with the XB-7 being surveyed six months later. The last of
the O-35s was surveyed in February of 1939. The two B-7s which had survived the
air mail ordeal were surveyed in 1938/39. No O-35/B-7 bombers survive today.
Serials:

Douglas XO-35 30-227
Douglas XO-36 --> XB-7 30-228
Douglas Y1B-7 32-308/314
Douglas Y1O-35 32-315/319

Specification of the Douglas Y1B-7
Two 640 hp Curtiss V-1570-33 or 675 hp V-1570-52 Conqueror twelve-cylinder
liquid-cooled Vee engines. Maximum speed: 182 mph at sea level, 177 mph at 5000
feet. Cruising speed: 155 mph. Landing speed 78 mph. Climb to 5000 feet in 3.7
minutes. Climb to 10,000 feet in 8.7 minutes. Service ceiling 20,400 feet,
absolute ceiling 21,800 feet. Normal range 411 miles, maximum range 632 miles.
Weights: 5519 pounds empty, 9953 pounds loaded, 11,177 pounds maximum
Dimensions: wingspan 65 feet, length 45 feet 11 inches, height 11 feet 7 inches,
wing area 621.2 square feet. Armed with two 0.30-inch machine guns, one in a
flexible nose position and the other in a flexible dorsal position. 1200 pounds
of bombs could be carried on racks underneath the fuselage.
Sources:


McDonnell Douglas Aircraft Since 1920: Volume 1, Rene J. Francillon, Naval
Institute Press, 1988


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


American Combat Planes, Ray Wagner, Third Edition, Doubleday, 1982.