E-152M / E-152P
The closure of the K-9 missile test program led to the termination of the flight to the E-152-2. Flight tests of this machine were carried out in a volume of 60%. The aircraft was decided to be converted into a new version of the E-152P , which was conceived as a base aircraft for the development of an interceptor fighter with a more advanced navigation and interception system.
The E-152P was designed for the installation of an upgraded engine, the R15B-300, and differed externally from the E-152-2 with a high dorsal spine extending to the base of the keel, as well as a new cockpit transparencies ["lantern"] without a flat windshield. The spine was increased in connection with the installation of three additional overhead fuel tanks on the fuselage behind the pilot's cabin. The total capacity of the fuel system was 6690 liters (of which 1760 liters in overhead tanks). Under the fuselage, one suspended fuel tank with a capacity of 1500 liters could be suspended. The total maximum fuel weight (with a suspension tank) reached 6800 kg. Unlike the E-152, the ejectors were replaced by narrowing-expanding nozzles, which reduced their length by 253 mm.
The tail empennage of the E-152P was identical to the tail empension of the E-152. The wing also did not differ from the wing of the E-152 aircraft except for a small aerodynamic crest on the lower surface (at half-stroke) and the location of the missiles on the endings. To reduce the load, the wing was equipped with two endings of a large area, which increased its swing (in comparison with the E-152 wing) by 1507 mm. In addition, in the nose of the E-152P fuselage, an anterior horizontal tail assembly (PGO) with a span of 3.50 m was installed, which was intended to improve longitudinal stability in the transition of the sound barrier.
An important feature of the E-152P was the installation on it of a new advanced weapon system. Its basis was to be the radar "Uragan-5B-80" (later called "Smerch"), designed to control large-size heavy air-to-air missiles K-80. In the process of working on a new version of the radar, its chief designer FF Volkov, who came to OKB-339 in November 1958, organized the development of a number of new units based on the previously created on-board locators with characteristics exceeding those of the Uragan-5B station blocks. First of all, this concerned the antenna block developed by NII-17. Even during the work on the project E-152P designers considered a number of options for the wing suspension of weapons, starting with the traditional (pylons under the wing) and ending with the most unusual (pylons on the bent wing tips).
However, for aerodynamic and strength reasons, it was initially decided to dwell on the method adopted for the E-152 interceptor. The K-80 missiles were suspended directly on the truncated wing tips. A similar system of weapons "Smerch" (the same locator and the same missiles) was installed and on the heavy long-range interceptor Tu-128 (originally called Tu-28) OKB-156 AN Tupolev. An experimental copy of the E-152P interceptor was built by reworking the E-152-2.
The constructed machine was slightly different from the one that was theoretically projected and calculated in the draft design. The real machine was given the nameE-152M. E-152M was tested, but it suffered the fate of its predecessors. Motor-builders have not managed to bring the engine. In addition, the launches of missiles with AAP, located on the wing sections, gave unsatisfactory results. Due to the lack of rigidity of the tips of the rocket during launch, it descended from the AAP unstably, continued its flight along an unpredictable trajectory, and as a result lost the target. This disadvantage was attempted to eliminate by setting the end pylons bent down by 90 ° and performing the function of the end stabilizing surfaces. In addition, the possibility of increasing the stiffness of the end part of the wing during missile launching was considered by additionally installing in the same place the wing cut of small, curled endings.
However, the analysis showed that, despite the possibility of some improvement in the conditions for the descent of missiles, compared with the suspension on the wing's half-span (as it was on the E-152A), they were worse. Therefore, the modification of the wing tips on the E-152M did not lead to production, and the launches of the experienced missiles had to be stopped.
The tests of the Uragan-5 system were suspended in 1961-1962, almost at the initial stage due to the complexity of the incoming components and the delay in the process of their creation, as well as the redistribution of resources in favor of space subjects and new ideas in the concept of constructing an air defense system. "Heavy MiGs" of the 150 series actually became flying laboratories for testing elements of new intercept systems for air targets (in particular, airborne radars, guidance equipment, missiles, powerful engines, etc.).
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