wer.15 He reached 37,650 metres (123,520 ft) at Podmoskovnoye, USSR in zoom climb (the absolute altitude record is different from the record for sustained altitude in horizontal flight). The aircraft was actually a MiG-25RB re-engined with the powerful R15BF2-300. It had earlier been part of the program to improve the aircraft's top speed that resulted in the MiG-25M prototype.6
In all 29 records were claimed, of which seven were all-time world records for time to height, altitudes of 20,000 m and higher, and speed. Several records still stand.6
Because of the thermal stresses incurred in flight above Mach 2, the Mikoyan-Gurevich OKB had difficulties choosing what materials to use for the aircraft. They had to use E-2 heat-resistant plexiglass for the canopy, and high-strength stainless steel for the wings and fuselage. Using titanium rather than steel would have been ideal, but it was expensive and difficult to work. The problem of cracks in welded titanium structures with thin walls could not be solved, so the heavier nickel steel was used instead. It cost far less than titanium and allowed for welding, along with heat resistant seals.6 The MiG-25 was constructed from 80% nickel steel alloy, 11% aluminium, and 9% titanium.16 The steel components were formed by a combination of spot-welding, automatic machine welding and hand arc welding methods.
Initially, the interceptor version was equipped with the TL-25 Smerch-A (also referred to as Product 720) radar, a development of the system carried by the earlier Tu-128. While powerful, and thus long-ranged and resistant to jamming, the system - due the age of its design and its intended purpose (tracking and targeting high- and fast-flying US bombers and reconnaissance aircraft), lacked Look-down/shoot-down capability, which limited its effectiveness against low-flying targets. By the time the MiG-25 entered service in 1969, this was a serious shortcoming, as strategic bombing doctrine was shifting towards low-level penetration of enemy territory. After Belenko's defection to Japan exposed this flaw to the West, a government decree issued on November 4, 1976 called for urgent development of a more advanced radar. This resulted in the pulse-Doppler Sapphire-25 system fitted to the MiG-25PD variant.
Automatic control system SAU 155П1 (interceptor) or SAU 155Р1 (scout): navigation system «Peleng-D (ETC, DM)»; heat radar 26Ш-1; корекция radio - guidance system «Lazur» (for interceptor); direction finder ARC-10; altimeter great heights RV-18 (RV-19); SPO Sirena-3M» or LO 06 «Birch»; control system air intake СРВМу-2A; system range radionavigation RSBN-6C «coral»; marker radio MCI-56П; intercom SPU-7; the Respondent CO-63B; system of air signals SVS-MO-5; voice informer RI-65; voice recorder MS-61 and others On late production was installed SEC «rainbow».
All interceptors installed «Polet-1I,» consisting of the electronic systems of navigation and landing, курсовертикали, air signals and systems of the automatic flight control. The spies were established: photographic equipment And 70 or A-72 station surveillance Cube-3M», radar side view «Sabre», the station of radio reconnaissance «Virazh» or «Pitch».
Armament interceptor includes four supersonic (M>5) UR great range R-40T (R-40TD) with thermal homing head and P-40P (R-40RD) with semi-active radar guidance system (maximum launch range, on altitudinal goal on a collision course - 35–60 km). Under the fuselage can suspended fuel tank. The aircraft could carry unguided gravity bombs in a rudimentary strike capability.17 As the bombs would weigh no more and incur no more drag than its regular load of R-40 missiles, its performance was not impaired, leading to some impressive bombing feats; when released at an altitude of 20,000m (66,000 ft) and a speed above Mach 2, a 500 kg bomb would have a glide range of several tens of kilometres.18
The MiG-25 was theoretically capable of a maximum speed of Mach 3+ and a ceiling of 90,000 ft (27,000 m). Its high speed was problematic: although sufficient thrust was available to reach Mach 3.2, a