Douglas O-2

The Douglas O-2 was a 1920s American observation aircraft built by the Douglas Aircraft Company.

Douglas O-2H at NACA Langley Research Center 1934
Role Observation plane
Manufacturer Douglas Aircraft Company
Primary user United States Army Air Corps
Produced 1924
Variants Douglas O-38
Douglas XA-2
Douglas M-1


The important family of Douglas observation aircraft sprang from two XO-2 prototypes, the first of which was powered by the 420 hp (313 kW) Liberty V-1650-1 V-engine and test-flown in the autumn of 1924. The second XO-2 was powered by the 510 hp (380 kW) Packard 1A-1500 Vee engine, which proved unreliable. The US Army ordered 45 O-2 production aircraft in 1925, these retaining the XO-2's welded steel tube fuselage, wooden wings and overall fabric covering but at the same time introducing aluminum panels on the forward fuselage. The XO-2 had been flown with short and long-span wings, the latter giving improved handling and therefore being specified for the production aircraft. The fixed tailskid landing gear included a main unit of the divided type, the horizontal tail surface was strut braced, and the engine was cooled by a tunnel radiator.[1]

The O-2 proved to be a conventional but very reliable biplane which soon attracted orders for 25 more aircraft: 18 O-2A machines equipped for night flying and six O-2B dual-control command aircraft for the US Army, plus one civil O-2BS modified specially for James McKee, who made a remarkable trans-Canada flight in September 1926. In 1927 the O-2BS was adapted as a three-seater with a radial engine.[1]

The O-2Hs were an entirely new design but continued the same basic model number. Major differences were heavily staggered wings, a more compact engine installation, and clean landing gear secured to the fuselage.[2]

Up to 2011 there were no O-2's known to exist. However, in 2011 the wreckage of O-2H 29-163 that crashed out of Kelly Field Texas on March 16, 1933 has been positively identified. The rear and central/forward portion of the fuselage behind the firewall, wing attachments and landing gear parts, tailplane and many engine parts and eight of the twelve pistons are now recovered. Research is continuing on this aircraft. It is known it was flown by Aviation Cadet Charles D. Rogers on a night recon advanced training mission. Apparently flying low, the aircraft hit a hill and burned after the crash leaving only the found wreckage today. Weather was not considered a contributing factor. Cadet Rogers was instantly killed in the crash by the impact. His body was recovered but the wreckage was abandoned due to the airframe and engine both being a writeoff.

The only similar aircraft known to exist are a restored Douglas M-2 mailplane and a follow-on derivative of the O-25 variant, an O-38.


Two pre-production prototypes.
Initial production model - 45 built.[1]
O-2 with night flying equipment - 18 built.[1]
Dual control version of O-2 - six built.[1]
These differed from the O-2 in having frontal radiators for their Liberty L-12 engines and modified oleo-strut landing gear. The USAAC took delivery of 18 aircraft, while the remaining 27 went to reserve National Guard units - 45 built and one later conversion from O-9.[1]
Unarmed staff transport versions of the O-2C - two built.[1]
A one-off aircraft which replaced the wire link between upper and lower wing ailerons of production aircraft by rigid struts.[1]
The fuselage was redesigned and a new tailplane was fitted, with staggered wings of unequal span. The O-2H incorporated the rigid-strut aileron interconnections of the O-2E. An improved split-axle landing gear was standard. The USAAC received 101 O-2Hs between 1928 and 1930, and the National Guard a further 40 - 141 built.[1]
Unarmed dual control version of the O-2H for service as USAAC staff transports - three built.[1]
A slightly modified version of the O-2J for US Army staff transport and liaison duties. 30 built for the USAAC and 20 for the National Guard - 50 built.[1]
various export versions of O-2 that saw services with Republic of China Air Force. These aircraft were used as scout-bombers by the Chinese in the Second Sino-Japanese War with somewhat limited success against Japanese ground targets. It was also used by the Mexican Air Force with Lewis and Vickers machine guns, with very good results.
Export version for China, powered by a Hornet radial engine - ten built
Export version for China, with the Hornet radial engine surrounded by a Townend ring - 20 built
Export version for China, fitted with an uprated 575 hp (429 kW) Pratt & Whitney Hornet radial engine - five built
Export version for China - 12 built
Export version for China, fitted with the less powerful 420 hp (310 kW) Pratt & Whitney Wasp C1 engine - 12 built
Export version for China, fitted with the 575 hp (429 kW) Wright R-1820-E radial engine - 22 built
Export version for China, fitted with a 670 hp (500 kW) Wright R-1820-F21 radial engine - one built
Five all-metal O-2s, built in the mid-1920s by Thomas-Morse.[1]
Radically altered (smaller and lighter) version of the XO-6 - one built.[1]
Three O-2s refitted with the 510 hp (380 kW) Packard 2A-1500 direct-drive engine. Two were later converted to O-2 standards, and one to the O-2C standard.[1]
One O-2 with the 400 hp (300 kW) Curtiss R-1454 radial engine instead of the intended Packard inverted-Vee engine. It later became an O-2A.[1]
One O-2 refitted with the 500 hp (370 kW) Packard 3A-1500 geared engine. It resembled the O-7 but had a four- rather than two-bladed propeller. It later became an O-2A.[1]
One reduced-scale O-2H, with a 220 hp (160 kW) Wright J-5 engine,[2] and the first Douglas aircraft with wheel brakes.[1]
The 46th aircraft of the original O-2 contract was completed as an attack machine with the powerplant of one 420 hp (310 kW) V-1410 Liberty inverted-Vee engine, and with a total of eight machine-guns (two in the engine cowling, two each in the upper and lower wings, and two on a ring-mounting operated by the observer). It was remarkably well armed for its day, and competed against the Curtiss A-3 in 1926 but was not selected for production.[1]
Two O-2Cs for service with the US Marine Corps from 1929.[1]
O-2H airframe with a swept-back upper wing and a Pratt & Whitney Wasp engine.[2]
O-2H airframe with a Curtiss Conqueror engine, and a revised nose. Later redesignated as the XO-25A [2]
Forty-nine production versions of the O-25.[2]
Three unarmed O-25As fitted with dual controls. Used as staff transport aircraft
29 production O-25s with Prestone cooling system
Later designated O-29A: Two O-2K airframes fitted with a Wright R-1750 Cyclone engine.[2]
O-2K conversion with Pratt & Whitney R-1340-3 Wasp engine, most later fitted with anti-drag rings.[2]
Production O-32, 30 built.
O-22 re-fitted with a Curtiss Conqueror engine.[2]
Douglas BT-1 and BT-2
BT-2 (left) and BT-1 at Waco, Texas
O-2K conversion to basic trainer, 30 converted.
O-32 airframe converted to basic trainer.
O-32A conversion to basic trainer, 30 converted.
First production model, 146 built. 58 later converted to BT-2BI instrument trainers. Two converted to BT-2BR and 15 to BT-2BG radio-controlled aerial target drones.
Second production model, 20 built. 13 converted to BT-2CI instrument trainers. Seven became BT-2CR drone controllers.
Seventeen BT-2BRs and BT-2BGs converted in 1940 as radio-controlled aerial target drones. These had tricycle gear (a steerable nosewheel was added) with main gear moved aft, faired-over rear cockpit, and single controls, allowing the aircraft to be test-flown.[3]


Three seat general purpose biplane derived from the M series of mail-planes, despite the O-2 designation


 United States

Specifications (O-2H)

Data from McDonnell Douglas aircraft since 1920 : Volume I[5]

General characteristics

  • Crew: 2
  • Length: 30 ft 0 in (9.14 m)
  • Wingspan: 40 ft 10 in (12.45 m)
  • Height: 10 ft 0 in (3.05 m)
  • Wing area: 362 sq ft (33.6 m2)
  • Airfoil: Clark Y [6]
  • Empty weight: 2,857 lb (1,296 kg)
  • Gross weight: 4,484 lb (2,034 kg)
  • Max takeoff weight: 4,550 lb (2,064 kg)
  • Fuel capacity: 110 US gal (92 imp gal; 420 l) in a single fuselage tank ahead of and below the pilot's cockpit
  • Powerplant: 1 × Liberty V-1650-1 V-12 liquid-cooled piston engine, 435 hp (324 kW)
  • Propellers: 2-bladed metal propeller


  • Maximum speed: 134.5 mph (216.5 km/h, 116.9 kn) at sea level
  • Cruise speed: 110 mph (180 km/h, 96 kn)
  • Range: 512 mi (824 km, 445 nmi)
  • Service ceiling: 16,900 ft (5,200 m)
  • Rate of climb: 1,075 ft/min (5.46 m/s)
  • Wing loading: 12.4 lb/sq ft (61 kg/m2)
  • Power/mass: 0.0971 hp/lb (0.1596 kW/kg)


  • 2 × .30 in (7.62 mm) Browning machine guns, one fixed forward-firing and one flexible
  • 400 lb (181 kg) of disposable stores carried under the lower wing


  1. ^ a b c d e f g h i j k l m n o p q r s Eden, Paul; Moeng, Soph (2002), The Complete Encyclopedia of World Aircraft, London: Amber Books, ISBN 978-0-7607-3432-2
  2. ^ a b c d e f g h Swanborough, F. G.; Bowers, Peter M. (1964), United States Military Aircraft Since 1909, New York: Putnam, ISBN 0-85177-816-X
  3. ^ Francillon, Rene. McDonnell Douglas Aircraft since 1920 (Putnam, 1979), p.89.
  4. ^ Home Video of flying K model (around 6 min)
  5. ^ Francillon, René J. (1988). McDonnell Douglas aircraft since 1920 : Volume I. London: Naval Institute Press. pp. 62–81. ISBN 0870214284.
  6. ^ Lednicer, David. "The Incomplete Guide to Airfoil Usage". Retrieved 16 April 2019.

External links

Media related to Douglas O-2 at Wikimedia Commons

107th Fighter Squadron

The 107th Fighter Squadron is a unit of the Michigan Air National Guard 127th Wing. It is assigned to Selfridge Air National Guard Base, Michigan and is equipped with the Fairchild Republic A-10 Thunderbolt II aircraft.

The squadron is a descendant organization of the World War I 107th Aero Squadron, established on 27 August 1917. It was reformed on 7 May 1926, as the 107th Observation Squadron, and is one of the 29 original National Guard Observation Squadrons of the United States Army National Guard formed before World War II.

108th Air Refueling Squadron

The 108th Air Refueling Squadron (108 ARS) is a unit of the Illinois Air National Guard 126th Air Refueling Wing located at Scott Air Force Base, Belleville, Illinois. The 108th is equipped with the KC-135R Stratotanker.

The squadron is a descendant organization of the World War I 108th Aero Squadron, established on 27 August 1917. It was reformed on 1 July 1927, as the 108th Observation Squadron, and is one of the 29 original National Guard Observation Squadrons of the United States Army National Guard formed before World War II.

113th Air Support Operations Squadron

The 113th Air Support Operations Squadron is a unit of the Indiana Air National Guard 181st Intelligence Wing located at Terre Haute Air National Guard Base (Hulman Field), Indiana.

The squadron is a descendant organization of the World War I 113th Aero Squadron, established on 26 August 1917. It was reformed on 1 August 1921, as the 113th Observation Squadron, and is one of the 29 original National Guard Observation Squadrons of the United States Army National Guard formed before World War II.

116th Air Refueling Squadron

The 116th Air Refueling Squadron (116 ARS) is a unit of the Washington Air National Guard 141st Air Refueling Wing located at Fairchild Air Force Base, Spokane, Washington. The 116th is equipped with the KC-135R Stratotanker and RC-26B Metroliner.

The squadron is a descendant organization of the World War I 116th Aero Squadron, established on 28 August 1917. It was reformed on 6 August 1924, as the 116th Observation Squadron, and is one of the 29 original National Guard Observation Squadrons of the United States Army National Guard formed before World War II.


2H or 2-H may refer to:

Deuterium, or 2H, an isotope of hydrogen

2nd half of a fiscal year

2H lead, a type of lead in a pencil

2H, a type of Toyota H engine

2H, a type of Volkswagen EA827 engine

Douglas O-2H, a model of Douglas O-2

Chaparral 2H, one model of Chaparral Cars

Aptera 2h, a model in the Aptera 2 Series

SSH 2H (WA), alternate designation for Washington State Route 290

2H, a designation for chemicals with two hydrogen molecules

2H-pyran, a form of Pyran

2H-1-benzopyran, a form of Benzopyran

2H-pyran-2-one, a form of 2-Pyrone

2nd Air Refueling Squadron

The 2nd Air Refueling Squadron, sometimes written as 2d Air Refueling Squadron, is a unit of the United States Air Force. It is part of the 305th Air Mobility Wing at Joint Base McGuire-Dix-Lakehurst, New Jersey. The 2nd Air Refueling Squadron is the second-oldest squadron in the Air Force, having over 100 years of service to the nation. Deployed to the Philippines after World War I, during the 1941-1942 Battle of the Philippines, it was wiped out, with the Japanese forcing some of the personnel to endure the Bataan Death March. It was re-formed as an air refueling squadron by Strategic Air Command in 1949. Today, it operates the KC-10 Extender aircraft, conducting aerial refueling missions.

44th Reconnaissance Squadron

The 44th Reconnaissance Squadron is an active squadron of the United States Air Force, stationed at Creech Air Force Base, Nevada, where it operates unmanned aerial vehicles. The squadron is assigned to the 732d Operations Group.

As the 430th Bombardment Squadron it saw combat with the 502d Bombardment Group in the closing months of World War II, flying from Northwest Field, Guam, earning a Distinguished Unit Citation. It remained in the Pacific until it was inactivated on 15 April 1946.

Dayton-Wright XO-3

The Dayton-Wright XO-3 was an aircraft project developed by Dayton-Wright in 1924.

Douglas Aircraft Company

The Douglas Aircraft Company was an American aerospace manufacturer based in Southern California. It was founded in 1921 by Donald Wills Douglas Sr. and later merged with McDonnell Aircraft in 1967 to form McDonnell Douglas, when it then operated as a division of McDonnell Douglas. McDonnell Douglas later merged with Boeing in 1997.

Douglas O-38

The Douglas O-38 was an observation airplane used by the United States Army Air Corps.

Between 1931 and 1934, Douglas built 156 O-38s for the Air Corps, eight of which were O-38Fs. Some were still in service at the time of the Pearl Harbor Attack in 1941.

The O-38 is a modernized derivative of the O-25, itself a re-engined variant of the earlier Douglas O-2.

Douglas XA-2

The Douglas XA-2 was an American prototype attack aircraft converted from a Douglas O-2 observation aircraft in the spring 1926 by Douglas Aircraft. Only one prototype aircraft was built and the type was not ordered into production.

Douglas mailplanes

The Douglas mailplanes were a family of 1920s American single-seat mail planes designed and built by the Douglas Aircraft Company. The aircraft were used to run the main routes of the United States Air Mail service until the introduction of three-engined aircraft in 1928.

Eugene Hoy Barksdale

Lieutenant Eugene Hoy Barksdale (November 5, 1896 – August 11, 1926) was a noted aviator and was a First Lieutenant in the United States Army Air Service and Army Air Corps. The new Barksdale Field (now Barksdale Air Force Base) in Bossier City/Shreveport, Louisiana, was named for him on February 2, 1933.

Fifth Air Force

The Fifth Air Force (5 AF) is a numbered air force of the United States Air Force Pacific Air Forces (PACAF). It is headquartered at Yokota Air Base, Japan. It is the U.S. Air Force's oldest continuously serving Numbered Air Force. The organization has provided 70 years of continuous air power to the Pacific since its establishment in September 1941.Fifth Air Force is the Headquarters Pacific Air Forces forward element in Japan, and maximizes partnership capabilities and promotes bilateral defense cooperation. In addition, 5 AF is the air component to United States Forces Japan.Its mission is three-fold. First, it plans, conducts, controls, and coordinates air operations assigned by the PACAF Commander. Fifth Air Force maintains a level of readiness necessary for successful completion of directed military operations. And last, but certainly not least, Fifth Air Force assists in the mutual defense of Japan and enhances regional stability by planning, exercising, and executing joint air operations in partnership with Japan. To achieve this mission, Fifth Air Force maintains its deterrent force posture to protect both U.S. and Japanese interests, and conducts appropriate air operations should deterrence fail.Fifth Air Force is commanded by Lieutenant General Kevin B. Schneider.

Liberty L-12

The Liberty L-12 was an American 27-litre (1,649 cubic inch) water-cooled 45° V-12 aircraft engine of 400 hp (300 kW) designed for a high power-to-weight ratio and ease of mass production. It was succeeded by the Packard 1A-2500.

List of Interwar military aircraft

Interwar military aircraft are military aircraft that were developed and used between World War I and World War II, also known as the Golden Age of Aviation.

For the purposes of this list this is defined as aircraft that entered service into any country's military after the armistice on 11 November 1918 and before the Invasion of Poland on 1 September 1939.

Aircraft are listed alphabetically by their country of origin. Civilian aircraft modified for military use are included but those that remained primarily civilian aircraft are not.

List of observation squadrons of the United States Army National Guard

United States Army National Guard units began forming Aerial Observation units before World War I. When the United States entered the war in April 1917, about 100 National Guard pilots joined the Aviation Section, U.S. Signal Corps (Later Air Service, United States Army).After the demobilization of the World War I Air Service in 1919, in 1920, the Militia Bureau and the Air Service agreed on forming postwar National Guard aviation units. On 17 January 1921 the 109th Observation Squadron of the Minnesota National Guard became the first postwar air unit to receive federal recognition. They flew a wide variety of aircraft during the inter-war period. These included the Curtiss JN-4 "Jenny", Consolidated PT-1 "Trusty", Consolidated PT-3, Northrop BT-1, Douglas O-2 and Consolidated O-17 Courier during 1923-1931; the Douglas O-38 during 1931-1935; and the Douglas O-43 and North American O-47 between 1935 and 1942.These 29 squadrons (18 of them having a World War I lineage and histories) formed by the Army before World War II remain active Air National Guard units today and are the direct predecessors of today's current units.


O9 or O-9 may refer to:

USS O-9 (SS-70), an O-class submarine of the United States Navy

O-9, the pay grade for the following senior officer ranks in the U.S. uniformed services:

Lieutenant General in the Army, Air Force, and Marine Corps

Vice Admiral in the Navy, Coast Guard, Public Health Service Commissioned Corps, and NOAA Commissioned Officer Corps

Douglas O-9, a variant of the Douglas O-2, a 1920s American observation aircraft

O9 (model railways)

USAAC/USAAF observation aircraft
Observation Amphibian
United States trainer aircraft designations, Army/Air Force and Tri-Service systems
Advanced Trainer
Basic Combat
Basic Trainer
Primary Trainer
Main sequence
Alternate sequences
USAAF drone aircraft
Controllable bombs
Target control aircraft
Aerial target (subscale)
Aerial target (full-scale)
Douglas military aircraft
Ground attack
Training aircraft


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