Technical data
Type	Yak-25RV
Function	Reconnaissater
Year	1959
Crew	1
Engines	2*3250/3900kg R-11B-300
Length	15.93m
Height	?m
Wingspan	23.4m
Wing area	55m²
Empty weight	6175kg
Loaded weight	9800kg
Wing Load (kg/m²)	178
Thrust to Weight	1,51
Speed at ?m	850km/h
Speed at 21000m	M=0.82
Range	3500km
Flight Endurance	5h30min
Ceiling	20500m

Yak-25RV, A.S.Yakovlev 'Mandrake'

At the Monino AF Museum near Moscow; Photo (35k) by

High altitude reconnaissance (so 'RV' for Razvedchick Vysotnyj) version of the Yak-25. Project of this unarmed aircraft started in 1957. Yak-25RV got a new straight wing, having a span of 23.4m (more than twice compared to the predecessor) and area 55m². As a result, the wing load turned less than for piston-engined Yak-3 fighter.

Test-flights at Flight-Research Institute (LII) (leading test-pilot V.P.Smirnov and test-pilot A.A.Scherbakov) were performed between March 1 and May 29 1959. Performance was quite good (see table), but at altitudes above 19600m sustained flight was not achieved due to engines spontaneous cut-off. Serious critics was addressed to pressurized suite SI-3M. V.P.Smirnov faced another high altitude peculiarity: it was very difficult to get back down due to very high airdynamic quality of the 'glider'. In one of flights pilot had to lower landing gear to force Yak-25RV to return home.

Another problem of aircraft was extremely narrow 'speed corridor' at stratospheric altitudes: difference between maximum (vibrations) and minimal (lost longitudinal stability) was only 10km/h. It imposed very heavy workload on pilots. But VVS Command had no other options, and production started. Yak-25RV and its modifications were in service for 15 years, replaced by high-speed MiG-25 reconnaissance derivatives.

75k photo at 'Russian Power'

Record flights were performed under designation 'RV':

July 13, 1959 (V.P.Smirnov): 20,456m with 1000kg load;
July 29, 1959 (V.P.Smirnov): 20,174m with 2000kg load;
April 10, 1961 (B.V.Polovnikov): 5h30min;
August 11, 1965 (M.L.Popovich): speed 753.048km/h on 2000km closed circuit;
September 18, 1967 (M.L.Popovich): 2497km closed circuit;

155 were built, including 81 unmanned Yak-25RV-II.

Predecessors	Modifications
Yak-25	Yak-25RV-I Yak-25RV-II	Yak-25RRV Yak-25PA

References	Links
'Aviatsia i vremia' 6/1997 "Russian aircraft since 1940" by Jean Alexander, p.477-482;	Yak-25RV 'Mandrake'