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Subject: Mikoyan-Gurevich MiG-25
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https://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-25
The Mikoyan-Gurevich MiG-25 (Russian: ?????? ? ??????? ???-25; NATO reporting
name: Foxbat) is a supersonic interceptor and reconnaissance aircraft that was
among the fastest military aircraft to enter service. It was designed by the
Soviet Union's Mikoyan-Gurevich bureau and is one of the few combat aircraft
built primarily using stainless steel. It was the last plane designed by Mikhail
Gurevich before his retirement.
The first prototype flew in 1964, and the aircraft entered service in 1970. It
has an operational top speed of Mach 2.83 (Mach 3.2 is possible but at risk of
significant damage to the engines) and features a powerful radar and four
air-to-air missiles. When first seen in reconnaissance photography, the large
wing suggested an enormous and highly maneuverable fighter, at a time when U.S.
design theories were also evolving towards higher maneuverability due to combat
performance in the Vietnam War. The appearance of the MiG-25 sparked serious
concern in the West and prompted dramatic increases in performance for the
McDonnell Douglas F-15 Eagle then under development in the late 1960s. The
capabilities of the MiG-25 were better understood in 1976 when Soviet pilot
Viktor Belenko defected in a MiG-25 to the United States via Japan. It turned
out that the aircraft's weight necessitated its large wings.
Production of the MiG-25 series ended in 1984 after completion of 1,186
aircraft. A symbol of the Cold War, the MiG-25 flew with Soviet allies and
former Soviet republics, remaining in limited service in several export
customers. It is one of the highest-flying military aircraft, one of the fastest
serially produced interceptor aircraft, and the second-fastest serially produced
aircraft after the SR-71 reconnaissance aircraft that was built in very small
series compared to the MiG-25. As of 2018, the MiG-25 remains the fastest manned
serially produced aircraft in operational use and the fastest plane that was
offered for supersonic flights and edge-of-space flights to civilian customers.
Work on the new Soviet interceptor that became the MiG-25 started in mid-1959, a
year before Soviet intelligence learned of the American Mach 3 A-12
reconnaissance aircraft. It is not clear if the design was influenced by the
American A-5 Vigilante.
The design bureau studied several possible layouts for the new aircraft. One had
the engines located side-by-side, as on the MiG-19. The second had a stepped
arrangement with one engine amidships, with exhaust under the fuselage, and
another in the aft fuselage. The third project had an engine arrangement similar
to that of the English Electric Lightning, with two engines stacked vertically.
Option two and three were both rejected because the size of the engines meant
any of them would result in a very tall aircraft which would complicate
maintenance.
The idea of placing the engines in underwing nacelles was also rejected because
of the dangers of any thrust asymmetry during flight. Having decided on engine
configuration, there was thought of giving the machine variable-sweep wings and
a second crew member, a navigator. Variable geometry would improve
maneuverability at subsonic speed, but at the cost of decreased fuel tank
capacity. Because the reconnaissance aircraft would operate at high speed and
high altitude, the idea was soon dropped. Another interesting but impractical
idea was to improve the field performance using two RD36-35 lift-jets. Vertical
takeoff and landing would allow for use of damaged runways during wartime and
was studied on both sides of the Iron Curtain. The perennial problem with
engines dedicated to vertical lift is they become mere deadweight in horizontal
flight and also occupy space in the airframe needed for fuel. The MiG
interceptor would need all the fuel it could get, so the idea was abandoned.
Role
Interceptor and reconnaissance aircraft
National origin
Soviet Union
Manufacturer
Mikoyan-Gurevich / Mikoyan
First flight
6 March 1964
Introduction
1970
Status
In limited service
Primary users
Soviet Air Defence Forces (historical)
Indian Air Force (historical)
Algerian Air Force
See Operators section for others
Produced
Number built
1,186
Developed into
Mikoyan MiG-31
Western intelligence and the MiG-25
Inaccurate intelligence analysis caused the West initially to believe the MiG-25
was an agile air-combat fighter rather than an interceptor. In response, the
United States started a new program which resulted in the McDonnell Douglas F-15
Eagle. NATO obtained a better understanding of the MiG-25's capabilities on 6
September 1976, when a Soviet Air Defence Forces pilot, Lt. Viktor Belenko,
defected, landing his MiG-25P at Hakodate Airport in Japan. The pilot overshot
the runway on landing and damaged the front landing gear. Despite Soviet
protests, the Japanese invited U.S. Air Force personnel to investigate the
aircraft. On 25 September, it was moved by a C-5A transport to a base in central
Japan, where it was carefully dismantled and analyzed. After 67 days, the
aircraft was returned by ship to the Soviets, in pieces. The aircraft was
reassembled and is now on display at the Sokol plant in Nizhny Novgorod.
The analysis, based on technical manuals and ground tests of its engines and
avionics, revealed unusual technical information:
Belenko's particular aircraft was brand new, representing the latest Soviet
technology.
The aircraft was assembled quickly and was essentially built around its massive
Tumansky R-15(B) turbojets.
Welding was done by hand. Rivets with non-flush heads were used in areas that
would not cause adverse aerodynamic drag.
The aircraft was built of a nickel-steel alloy and not titanium as was assumed
(although some titanium was used in heat-critical areas). The steel construction
contributed to the craft's high 29,000 kg (64,000 lb) unarmed weight.
the resulting deformation damaged the airframe beyond repair.
Combat radius was 299 kilometres (186 mi), and maximum range on internal fuel
(at subsonic speeds) was only 1,197 kilometres (744 mi) at low altitude (< 1000
metres).
The airspeed indicator was redlined at Mach 2.8, with typical intercept speeds
near Mach 2.5 in order to extend the service life of the engines. A MiG-25 was
tracked flying over Sinai at Mach 3.2 in the early 1970s, but the flight led to
the engines being damaged beyond repair.
The majority of the on-board avionics were based on vacuum-tube technology, not
solid-state electronics. Although they represented aging technology, vacuum
tubes were more tolerant of temperature extremes, thereby removing the need for
environmental controls in the avionics bays. With the use of vacuum tubes, the
MiG-25P's original Smerch-A (Tornado, NATO reporting name "Foxfire") radar had
was designed to be as robust as possible. The use of vacuum tubes also made the
aircraft's systems resistant to an electromagnetic pulse, for example after a
nuclear blast
The unarmed 'B' version had greater impact than the interceptor when the USSR
sent two MiG-25R and two MiG-25RB to Egypt in March 1971 and stayed until July
1972. They were operated by the Soviet 63rd Independent Air Detachment (Det 63),
which was established for this mission. Det 63 flew over Israeli-held territory
in Sinai on reconnaissance missions roughly 20 times. The flights were in pairs
at maximum speed and high altitude, between 17,000 and 23,000 m (55,000 to
75,000 ft). On 6 November 1971, a Soviet MiG-25 operating out of Egypt flying at
Mach 2.5 was met by Israeli F-4Es and fired upon unsuccessfully. A MiG-25 was
tracked flying over Sinai at Mach 3.2 during this period. The MiG-25 engines
went into overspeed, which led to them being scrapped. Det 63 was sent back home
October 1973, during the Yom Kippur War. Det 154 remained in Egypt until late
1974.
During the 1970s, the Soviet air force conducted reconnaissance overflights
across Iran using its MiG-25RBSh aircraft in response to joint US-Iran recon
operations.
The Swedish Air Force observed Soviet Air Defence MiG-25s via radar regularly
performing intercepts at 19,000 m (63,000 ft) and 2.9 km (1.8 mi) behind the
Lockheed SR-71 Blackbird at 22,000 m (72,000 ft) over the Baltic Sea in the
1980s
Specifications (MiG-25P)
General characteristics
Crew: 1
Length: 19.75 m (64 ft 10 in)
Wingspan: 14.01 m (45 ft 11.5 in)
Height: 6.10 m (20 ft 0.25 in)
Empty weight: 20,000 kg (44,080 lb)
Loaded weight: 36,720 kg (80,952 lb)
(16,524 lbf) each
Thrust with afterburner: 100.1 kN (22,494 lbf) each
Performance
Maximum speed:
High altitude: Mach 2.83 (3,000 km/h; 1,920 mph)
Low altitude: 1100 km/h IAS
Range: 1,860 km at Mach 0.9; 1,630 km at Mach 2.35 ()
Ferry range: 2,575 km (1,390 mi; 1,600 nmi)
Service ceiling: 20,700 m (67,915 ft) with four missiles (24,000 m (78,740 ft)
with two)
Rate of climb: 208 m/s (40,950 ft/min)
Thrust/weight: 0.41
Time to altitude: 8.9 min to 20,000 m (65,615 ft)
Maximum g-load: 4.5 g
Armament
Missiles:
Avionics
RP-25 (Smerch A-4) radar based on Vaccum tube electronics, for early Mig-25P.
RP-25MN (Saphir-25) radar based on semiconductor electronics, for later MiG-25PD
A RV-UM or a RV-4 radar altimeter
*
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