Yakovlev Yak-11

Yakovlev Yak-11
Jak-11 of the NVA in the airfield museum Cottbus
Type:	School fighter plane
Design country:	Soviet Union
Manufacturer:	OKB Yakovlev
First flight:	November 10, 1945
Production time:	1946 to 1956
Number of pieces:	3,859 + 707 (license)

The Jakowlew Jak-11 ( Russian Яковлев Як-11 , NATO code name " Moose ") was a single-engine aircraft from Soviet production. The two - seat low- wing aircraft was specially designed for advanced training of fighter pilots and used in all member states of the Eastern Bloc and the Warsaw Pact as well as in the Middle East ( Egypt , Yemen ), China and Austria . In Czechoslovakia , the type was built in large numbers under license.

development

When designing the Jak-11, which was put on paper from 1944, the designer Alexander Jakowlew oriented himself on the Jak-3 , the last link in the chain of Jak-fighters in World War II . In contrast to the predecessor, an ASch-21 radial engine was provided instead of the V-engines previously used . As with many Soviet aircraft designs of the time, emphasis was placed on simple production and maintenance; there were various detachable fairings and flaps that made it easier to access the engine. The two-bladed adjustable propeller was initially curved into a sickle shape, but was later replaced by the straight 3 m propellers of the type WISch-111-W20 or WISch-11-D-15 .

On November 10, 1945, the first prototype under the name Jak-3UTI took off on its maiden flight and then completed the trial, which lasted about a year, during which some changes were made to the machine. Series production began in 1946/47 and ended in the Soviet Union after 3859 copies were built. In the second half of the 1950s, the Jak-11U (also: Jak-10) appeared as a reaction to the standard configuration of the nose-wheel landing gear on fighter aircraft, also with a nose-wheel.

From 1951 to 1954, the Jak-11 set four international records that were recognized by the FAI .

License version Let C-11

From 1952 to 1956, 707 Jak-11s were built under license at the Kunovice aircraft plant (Czechoslovakia). They were referred to as Let C-11 (whereby stringers and frames made of wood were partially replaced by metal) and in the case of the nose wheel version C-11U .

In normal flight operations, the Jak-11 was used to train pilots who had already gained some flying experience on the Jak-18 beginner's training aircraft . For shooting tests, the Yak-11 therefore also had a built-in fuselage nose synchronized 12.7 mm machine gun UBS and a photo-MG in the front, occupied by student pilots cabin to check the results. The Jak-11 was used for active training until the late 1950s and was used for secondary tasks until the 1960s. For example, the last four to five of the approximately 100 Yak-11s delivered to the air forces of the NVA in the GDR flew until 1962 in the ZD-21 (target display squadron) as target aircraft for ground defense; the majority had already been separated in 1958/59.

technical description

The Jak-11 was constructed in composite construction. The fuselage consisted of a welded tubular steel frame, which was mostly clad with plywood, only the underside was covered with fabric. The bow was made of metal in the area of ​​the engine mount.
The wing in the low- wing design had two main spars, between which the fuel tanks were located, and was also made of metal. It had an external suspension for a 25 kg or 50 kg bomb on each underside. The landing gear shaft was also equipped with an auxiliary spar made of Dural.
The tail unit was self-supporting and manufactured in a normal construction.
In the stern wheel design, only the main wheels could be retracted, in the nose wheel design the entire landing gear.

Speed ​​and distance records

Class C-1-d (aircraft with a flight weight of 1750-3000 kg)

• 471.348 km / h on a closed 500 km route, established on July 11, 1951 by J. D. Forestenko
• 442.289 km / h on a 1000 km route, set up on August 26, 1951 by N. Golovanov
• 360.032 km / h on a 2000 km route, established on October 31, 1953 by Father Sakhudalin
• 1990.183 km on a straight route, erected on September 11, 1954 by I. Tschernow

Military users

Jak-11 of the Polish Air Force in the Poznań Military Museum

Czechoslovak C-11 in the Kbely Aviation Museum

•  Egypt
•  Afghanistan : 14 from 1958
•  Albania : 4
•  Algeria
•  Bulgaria
•  People's Republic of China
•  German Democratic Republic : about 100 from 1953 to 1962
•  Iraq
•  Yemen
•  Mongolia
•  North Korea
•  Austria : 4 from 1955 to 1965
•  Poland : 101 Jak-11 and 37 C-11
•  Romania : 90
•  Somalia
•  Soviet Union :

Soviet Union Air Force

DOSAAF

•  Syria
•  Hungary
•  Czechoslovakia
•  Vietnam

Technical specifications

Three-sided tear

Parameter	Data
span	9.40 m
length	8.50 m
height	3.23 m
Wing area	15.40 m²
Empty weight	1,811 kg
Takeoff weight	2,373 kg to max. 2,480 kg
Top speed	475 km / h at an altitude of 2,250 m
Cruising speed	350-400 km / h
Landing speed	127 km / h
Take-off run	365 m
Landing runway	500 m
Service ceiling	7,100 m
Climb performance	9.0 m / s
Range	1,280 km
crew	1–2 (student pilots / flight instructors)
Engine	an air-cooled 7-cylinder radial engine Schwezow ASch-21
Starting power	515 kW (700 hp) at 2300 rpm
Fuel supply	360 l
Armament	one 12.7 mm MG UBS or one 7.7 mm MG SchKAS two 50 kg bombs

Museum reception

• A Jak-11 of the NVA air force (WNr. 68203) can be viewed in the Military History Museum on the grounds of the Berlin-Gatow airfield .
• Another Jak-11 of the NVA (WNr. 68210) is in the holdings of the Cottbus Airfield Museum on the grounds of the Cottbus Airfield (see photo info box)
• A Jak-11 of the Austrian Armed Forces is on display in the military aviation exhibition Zeltweg in hangar 8 of the Hinterstoisser air base, a branch of the Vienna Museum of Military History .

See also

• List of aircraft types

Web links

Commons : Jakowlew Jak-11  - Collection of pictures, videos and audio files

• Let C-11 of the Classic Aviation Company

Individual evidence

1. ↑ Detlef Billig, Manfred Meyer: Aircraft of the GDR Volume 1. TOM Modellbau, Friedland 2001, ISBN 3-613-02197-6 , pp. 90–95
2. ↑ Doppeladler.com
3. ^ Detlef Billig, Manfred Meyer: Airplanes of the GDR Volume 1. TOM Modellbau, Friedland 2001, ISBN 3-613-02197-6 , p. 180
4. ↑ on doppeladler.com , accessed on September 10, 2013