Fokker O-27

Fokker O-27
Atlantic (Fokker) XB-8
Type:	Trainer aircraft
Design country:	United States
Manufacturer:	Fokker Aircraft Corporation of America
First flight:	1930 (XO-27)
Number of pieces:	14 (1 × XO-27, 1 × XB-8, 6 × YO-27, 6 × Y1O-27)

The Fokker O-27 (Atlantic-Fokker Model 16) was a light observation, bombing and close air support aircraft designed by the US manufacturer Fokker Aircraft Corporation of America , which was produced for the United States Army Air Corps (USAAC ) was built. However, the O-27 was only used as a trainer aircraft. After General Motors had acquired a 41 percent stake in the Fokker Aircraft Corporation of America in May 1929 and the company was renamed General Aviation Corporation (GAC) a year later , the GAC fulfilled Fokker's production obligations.

history

Based on the experience gained with the Fokker F.VII-3m , Fokker-America designed a twin-engine observation aircraft with retractable landing gear to replace the increasingly outdated Douglas O-25 . On June 7, 1929, the US Department of War ordered two prototypes ( USAAC serial numbers 29-327 and 29-328 ) of the cantilever monoplane, which was given the military designation XO-27, at a price of US $ 30,600.

At the same time, the Air Corps was also looking for a replacement for the already obsolete Keystone B-6 bomber . The contract with Fokker was therefore changed in such a way that the second prototype as a fast day bomber under the designation XB-8 was to be completed. Douglas was also asked to convert one of the two YO-35s commissioned into an XB-7 light bomber.

As with the XO-27, a three-person crew was provided for the XB-8, consisting of a pilot and two gunner, one of whom was also to act as a bombardier. The flight tests at Fokker began in 1930 in Teterboro, the factory location. The tests by the Air Corps took place from October 1930 on the Wright Field and on one of the two airfields in Kenilworth (New Jersey) . As a result, the XB-8 performed only slightly better than the USAAC bombers already in service. Accordingly, the already issued construction contract for two further prototypes (YB-8) and four field test aircraft (Y1B-8) was changed to an order for six YO-27 machines (serial numbers 31-587 to 31-592). The contract was signed with Fokker on March 30, 1931. The engines initially used (two 600 hp Curtiss GIV-1570C Conquerors) were replaced in December 1932 by two GIV-1570F with reduction gears.

The order was followed by a second order on May 5, 1931 for six, largely identical Y1O-27s with the serial numbers 31-598 to 31-603. The 14 aircraft were delivered to the USAAC between May 1932 and January 1933. Upon completion of the tests, all YO-27 and Y1O-27 were renamed O-27 . The designation XO-27A was given to the XO-27 after it had been brought up to date with the YO-27. The aircraft were used in five different squadrons. These were the 12th Observation Sqn. (12th OS) in Brooks Field (Texas), which until April 1935 used five machines with the hull numbers "1" to "5". From April 1935, the 88th OS used the Y1O-27, taken over from the 12th OS, with body numbers in the 170 range. At least one O-27 flew at the 36th Pursuit Sqn in Langley Field, Virginia. The 30th and 32th Bomber Sqns in Rockwell Field (California) used Y1O-27 from June 1932. The machines were used in the units primarily for training night flights, long-haul flights and training in radio communications. The last two airworthy O-27s were deleted from the inventory in early 1937; with that, the last Fokker model used by the American military also disappeared.

construction

The O-27 or XB-8 was a self-supporting, non-braced monoplane equipped with a retractable landing gear. The wings were braced internally in classic Fokker wood construction and planked with plywood. The thick profile corresponded to the type that Fokker also used in its commercial aircraft at the time. The fuselage had a load-bearing structure consisting of a welded frame made of stainless steel tubes. Individual areas were clad with corrugated duralumin sheets. The rest of the fuselage was made into an approximately oval shape with wooden moldings and covered with fabric. The landing gear retracted back into the engine nacelle, but the wheels were only partially covered. The drive consisted of two twelve-cylinder V-engines of the type Curtiss V-1570-9 Conqueror, which each delivered 600 hp (447 kW).

Technical specifications

All data from Pelletier, 2005, p. 64

Parameter	XO-27	XB-8	YO-27 / Y1O-27
crew	3	3	?
length	14.42 m	14.42 m	14.48 m
span	19.50 m	19.60 m	19.68 m
height		3.5 m
Wing area		57.5 m²	57.5 m²
Empty mass		3108 kg	3108 kg
Takeoff mass	4040 kg	4824 kg	4820 kg
Top speed	257 km / h	257 km / h	285 km / h
drive	2 × Curtiss V-1570 -9 "Conqueror" with 600 PS (450 kW) each	2 × V-1570-23 with 600 PS (450 kW) each	2 × V-1570-29 with 600 PS (450 kW) each

literature

• Alain J. Pelletier: Fokker Twilight - Last of the US Military Fokkers . In: AIR Enthusiast May / June 2005 No. 117, pp. 62-66
• John M. Andrade: US Military Aircraft Designations and Serials since 1909 , Midland Counties Publ., 1979, ISBN 0-904597-22-9 , pp. 43, 138

Web links

Commons : Fokker XB-8  - collection of images, videos and audio files

• Fokker XB-8 , Encyclopedia of American Aircraft
• YO-27 USAAC serial no. 31-592 in action at the 12th Observation Sqn.
• YO-27
• Brief historical summary
• Top view of a YO-27

Individual evidence

1. ↑ Note: The addition "Y1" used between 1931 and 1936 only indicated that the model was financed with additional funds outside the regular fiscal year. There was not necessarily a technical difference.
2. ^ Andrade, 1979, p. 138