Tu-138 long-range supersonic fighter-interceptor

In the second half of the 1960s the bureau headed by Andrei Tupolev, continued design work on the new long-range interception for air defense of the country. As of 1963-1964 they prepared by two similar project complexes distant interception, designated Tu-Tu-138-60 and 138-100, which had basically the same design aircraft carrier "138" (Tu-138) and differed types of board radar missiles.

The aircraft "138" retained the overall layout of the Tu-128, but differs from it a new power plant with WD-19 engines, improved aerodynamics due to the new aerodynamically clean wing with a smaller relative thickness and form a new plan. Unlike the Tu-128, the main landing gear wheels on a plane "138" retracted into the wing root and partially in the fuselage. For complex Tu-138-60 was supposed to use the radar of the "Smerch-A" and missiles K-60, for complex Tu-138-100 - radar "Thunderstorm" and missiles K-100. Providing for the use of missiles K-80 (P-4) complex Tu-28-80 (Tu-128C-4).

Modernization of the aircraft carrier, radar and missiles had significantly enhance the ability of the complex to intercept high-speed targets. For example, the maximum speed with missiles increased to 800 km / h, increases the time loitering, improved takeoff and landing performance, increased range of detection and capture objectives radar and range missiles.

During the design of the aircraft "138" models were conducted aerodynamic studies that had shown that the necessary aerodynamic efficiency at cruising subsonic flight cannot be obtained due to a significant increase in the midsection of the fuselage (WD-19 and a new radar station had a larger diameter), and hence jeopardized the achievement of the required range and duration of the flight, which was one of the most important requirements for the interceptor. New thin wings obtained the desired takeoff and landing characteristics.

In order to solve the problems they proposed various options for completion of the project. Wanted to introduce a system of in-flight refueling "cone" of blowing boundary layer flaps and leading edge flaps or achieve greater aerodynamic efficiency of the wing due to boundary layer suction.

However, all these measures or weighting structure, or significantly reduced the efficiency of the power plant due to the selection of air blowing system. By the mid-1960s, in KB it was decided to conduct further work on ways to modernize the distant interception on the basis of aircraft with variable sweep wing, which was proposed in the draft "148". Since the beginning of work on this property, all work on the project "138" were discontinued.

In addition to several projects of the aircraft "138", made by the schemes basically follow the original Tu-128, the OKB was offered several options for projects, "138", were based on non-traditional schemes, in particular, have been proposed scheme tailless delta wing and a canard ["duck"]. In addition to the engines of WD-19, for the aircraft "138" considered the possibility of using the RD-36-41.