Early years

Østby attended the Norwegian Naval Flying School from 1924, graduating in 1925. He soon became an instructor, then test pilot at Marinens Flyvebaatfabrikk

Marinens Flyvebaatfabrikk

Marinens Flyvebaatfabrikk - The Navy's Flying Boat Factory - was the Royal Norwegian Navy Air Service' aeroplane producer. It was established in Horten in 1915.It produced a total of 120 planes from 1915 to 1940.-Planes produced:...

.

World War II

The Marinens Flyvebaatfabrikk M.F.12

Marinens Flyvebaatfabrikk M.F.12

-Bibliography:...

 (sometimes known as the Høver M.F.12, after its designer) was a seaplane built in Norway in 1939 as a military trainer aircraft to replace the Royal Norwegian Navy Air Service

Royal Norwegian Navy Air Service

The Royal Norwegian Navy Air Service was alongside the Norwegian Army Air Service the forerunner to the modern-day Royal Norwegian Air Force.- History :...

's aging fleet of M.F.8

Marinens Flyvebaatfabrikk M.F.8

-References:...

 trainers.In 1939, Østby was the factory's control officer and also responsible for introducing the Heinkel He 115

Heinkel He 115

The Heinkel He 115 was a World War II Luftwaffe seaplane with three seats. It was used as a torpedo bomber and performed general seaplane duties, such as reconnaissance and minelaying. The plane was powered by two 720 kW BMW 132K nine-cylinder air-cooled radial engines...

 torpedo bombers ordered by the RNNAS.

With Captain Birger Motzfeldt of the Norwegian Army Air Service

Norwegian Army Air Service

The Norwegian Army Air Service ' was established in 1914. Its main base and aircraft factory was at Kjeller. On 10 November 1944 the NoAAS was joined with the Royal Norwegian Navy Air Service to form the Royal Norwegian Air Force....

, Østby was instrumental in the purchase of aircraft from the United States just prior to the German invasion of Norway in 1940. Norway

Norway

Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...

 had recognised that the equipment of its armed forces was obsolete, and sent a purchasing commission to the United States in February 1940, including a Royal Norwegian Navy Air Service contingent headed by Cmdr. Østby. Amongst the requirements the commission hoped to fill was to replace the Royal Norwegian Navy Air Service

Royal Norwegian Navy Air Service

The Royal Norwegian Navy Air Service was alongside the Norwegian Army Air Service the forerunner to the modern-day Royal Norwegian Air Force.- History :...

's M.F.11 biplane patrol aircraft.

After visits to many of the aviation companies, Østby determined that only one manufacturer had both a design, company designation Model 8-A and available production capacity, Northrop Aircraft Incorporated

Northrop Corporation

Northrop Corporation was a leading United States aircraft manufacturer from its formation in 1939 until its merger with Grumman to form Northrop Grumman in 1994. The company is known for its development of the flying wing design, although only a few of these have entered service.-History:Jack...

. The commission ordered 24 floatplanes renamed the Northrop N-3PB

Northrop N-3PB

The Northrop N-3PB Nomad was a single-engined American floatplane of the 1940s. Northrop developed the N-3PB as an export model based on the earlier Northrop A-17 design. A total of 24 were purchased by Norway, but were not delivered until after the Fall of Norway during the Second World War...

 "off the drawing board" (literally, the aircraft being ordered prior to the type having flown) from Northrop on 8 March 1940, at a total cost of to meet this requirement.Østby remained at Northrop as the head of the Norwegian acceptance team of 12 technical staff and flight crews who worked closely with design and production personnel at the plant. He supervised all the final fitting of equipment and participated in the flight testing of the N-3PDs at Lake Elsinore, California

Lake Elsinore, California

For the lake see Lake Elsinore.Lake Elsinore or LE is a city in western Riverside County, California. The population was 51,821 at the 2010 census...

.
When the final N-3PD production run was completed in March 1941, Østby was appointed air attaché to the Norwegian embassy in Washington. After arriving in the United Kingdom, the Norwegian government-in-exile began the process of setting up a new base of operations. A decision was swiftly made to keep the existing Norwegian pilots that had escaped to the United Kingdom, as an independent unit, consequently, none were allowed to participate in the Battle of Britain

Battle of Britain

The Battle of Britain is the name given to the World War II air campaign waged by the German Air Force against the United Kingdom during the summer and autumn of 1940...

. Østby worked with Bernt Balchen

Bernt Balchen

Bernt Balchen, , a winner of the Distinguished Flying Cross was a Norwegian native, and later U.S. citizen, known as a pioneer polar aviator, navigator, aircraft mechanical engineer and military leader. His service in the U.S...

, a Norwegian aviator, who enlisted with the Norwegian Air Force and had come to the United States on a crucial mission to negotiate "matters pertaining to aircraft ordnance and ammunition with the question of the Norwegian government's possible purchase of such materials in the United States of America."

The Norwegian Government-in-exile in London changed to a new directive: to set up a training camp and school for expatriate Norwegian airmen and soldiers in Canada and Østby was one of the principal "architects" of the training program, helping to negotiate with Canadian government officials to obtain an agreement to use available airport facilities in Canada. Arrangements were made to transfer Norwegian pilots to a North American headquarters while various locations were considered, a base around the Toronto Island Airport in Canada was chosen. Once the base known as "Little Norway

Little Norway

The Flyvåpnenes Treningsleir , the official name) or "Little Norway" was a Norwegian Army Air Service/Royal Norwegian Air Force training camp in Canada during the Second World War.-Origins:...

" was established, young Norwegians migrated to the site to enroll in the RNAF in Canada.

Postwar

After the war Østby served in the Norwegian Air Force in several technical positions, among others as director of Horten flyfabrikk

Marinens Flyvebaatfabrikk

Marinens Flyvebaatfabrikk - The Navy's Flying Boat Factory - was the Royal Norwegian Navy Air Service' aeroplane producer. It was established in Horten in 1915.It produced a total of 120 planes from 1915 to 1940.-Planes produced:...

 and Kjeller Flyfabrikk

Kjeller Flyfabrikk

Kjeller Flyfabrikk was a Norwegian manufacturer of military aircraft. It was formally established in 1915, but was active from 1912. The factory was owned by the Norwegian Government under the management of the Norwegian Army Air Service...

. Østby retired from the Norwegian Air Force in 1963 as a colonel.