The nuclear euphoria of the fifties of the last century gave rise to a lot of bold ideas. The fission energy of the atomic nucleus was proposed to be used in all spheres of science and technology, or even in everyday life. Aircraft designers did not leave her unattended either. The high efficiency of nuclear reactors, in theory, made it possible to achieve incredible flight characteristics: new aircraft with nuclear engines could fly at high speeds and cover up to several hundred thousand miles at one "refueling". However, all these advantages of nuclear power were more than offset by disadvantages. The reactor, including the aviation one, had to be equipped with a whole range of protective equipment so that it would not pose a danger to the crew and service personnel. In addition, the question of the optimal system of a nuclear jet engine remained open.
Around the mid-fifties, American nuclear scientists and aircraft designers decided on a range of problems that must be solved for the successful construction of a serviceable aircraft with a nuclear power plant. The main problem that prevented the creation of a full-fledged atomic machine was the radiation hazard. The acceptable protection of the reactor turned out to be too large and heavy to be lifted by the planes of that time. The dimensions of the reactor led to a host of other problems, both technical and operational.
Among others, they worked on the problem of the appearance of a practically applicable atomic aircraft at Northrop Aircraft. Already in 1956-57, they developed their own views on such technology and determined the main features of such an aircraft. Apparently, the Northrop company understood that the atomic machine, with all its advantages, remains too complicated for production and operation, and therefore it is not necessary to hide the main ideas of its appearance under secrecy labels. So, in April 1957, Popular Mechanics magazine published interviews with several scientists and employees of Northrop, who were involved in defining the shape of an atomic aircraft. In addition, this topic was subsequently repeatedly raised by other publications.
A team of engineers at Northrop, led by nuclear technology specialist Lee A. Olinger, worked on the design of a promising aircraft, solving technical problems as they came up and applying the simplest and most obvious solutions. So, the main problem of all atomic-powered aircraft - the unacceptably large dimensions and weight of a power plant with a nuclear reactor - was tried to be solved by simply increasing the size of the aircraft. Firstly, this would help to optimally manage the internal volumes of the aircraft, and secondly, in this case, it would be possible to separate the cockpit and the reactor as much as possible.
With an aircraft length of at least 60-70 meters, two basic layouts could be used. The first implied the standard placement of the cockpit in the nose of the fuselage and the reactor located in the rear of it. The second idea was to install a reactor in the nose of the aircraft. In this case, the cockpit should have been located on the keel. This design was much more complex and therefore it was considered exclusively as an alternative.
The purpose of the work of the Olinger group was not just to determine the appearance of a promising atomic aircraft, but to create a preliminary draft of a certain supersonic strategic bomber. In addition, it was planned to evaluate the possibility of developing and building a passenger or transport aircraft with high flight performance. All this was taken into account when working out the appearance of the base bomber and significantly influenced its design.
So, the requirements for speed led to the fact that the projected hypothetical aircraft received a delta wing located at the rear of the fuselage. The tailless scheme was considered the most promising in terms of layout. It made it possible to move the reactor as far as possible from the cockpit located in the nose of the aircraft, and thereby improve the working conditions of the crew. Nuclear turbojet engines were supposed to be placed in a single package above the wing. Two keels were provided on the upper surface of the wing. In one of the variants of the project, in order to improve flight performance, the wing was connected to the fuselage using a long and powerful pylon.
The greatest questions were raised by the nuclear power plant. The experimental designs of reactors available in the mid-fifties, the dimensions of which theoretically allowed them to be installed on airplanes, did not meet the weight requirements. An acceptable level of protection could only be provided by a multilayer structure made of metals, concrete and plastic weighing about 200 tons. Naturally, this was too much even for a large and heavy aircraft with an estimated weight of no more than 220-230 tons. Therefore, aircraft designers could only hope for the early appearance of less heavy means of protection with sufficient characteristics.
Engines were another controversial point. Most of the "concept art" of a promising atomic aircraft depicts aircraft with eight jet engines. For objective reasons, namely, due to the lack of ready-made nuclear turbojet engines, Northrop engineers considered two options for a power plant, with open and closed circuit motors. They differed from each other in that in the first type engine, with an open cycle, the atmospheric air after the compressor had to go directly into the reactor core, where it was heated, and then redirected to the turbine. In a closed-cycle engine, the air should not leave the channel and be heated from the heat exchanger in the flow with the coolant circulating in it from the reactor circuit.
Both schemes were very complex and hazardous to the environment. An open-cycle engine, in which the outside air was in contact with the elements of the core, would leave a radioactive trace behind it. The closed cycle was less hazardous, but transferring enough energy from the reactor to the heat exchanger proved to be quite challenging. It must be remembered that American designers began working on the creation of nuclear jet engines for aircraft back in the late forties. However, for more than ten years they did not manage to build a workable engine suitable for installation even on an experimental aircraft. For this reason, Olinger's team had to operate only with some hypothetical numbers and the promised parameters of the engines being created.
Based on the characteristics declared by the developers of the engines, the engineers of the Northrop company have determined the approximate flight data of the aircraft. According to their calculations, the bomber could accelerate to a speed three times the speed of sound. As for the flight range, this parameter was limited only by the capabilities of the crew. In theory, it was even possible to equip a bomber with a household block with lounges, a kitchen and a bathroom. In this case, several crews could be on the plane at once, working in shifts. However, this would only be possible with the use of powerful protection. Otherwise, the flight duration should not have exceeded 18-20 hours. Calculations have shown that such an aircraft could fly at least 100 thousand miles at one refueling with nuclear fuel.
Regardless of the scheme and type of the finished engine or flight characteristics, the new aircraft turned out to be large and heavy. In addition, it was supposed to be equipped with a delta wing, which has specific aerodynamic qualities. Thus, a nuclear strategic bomber needed a particularly long runway. The construction of such an object promised huge costs, because of which only a few new airfields could "gnaw" a solid hole in the military budget. In addition, the military could not quickly build a wide network of such airfields, which is why promising bombers risked remaining tied to only a few bases.
The problem of basing was proposed to be solved in a fairly simple, but original way. Ground airfields were supposed to be left only for transport aircraft, or not to build them at all. Strategic bombers, in turn, were supposed to serve at coastal bases and take off from the water. To this end, Olinger's group introduced a ski chassis adapted for takeoff and landing on the water into the shape of the atomic aircraft. If necessary, the bomber could probably be equipped with a wheeled landing gear, but only the surface of the water was supposed to be used as a runway.
In an interview with Popular Mechanics magazine L. A. Olinger estimated the time frame for the creation of the first prototype atomic aircraft at 3-10 years. Thus, by the end of the sixties, the Northrop company could begin to create a full-fledged project of a strategic supersonic bomber with nuclear turbojet engines. However, the potential customer of such equipment thought differently. All the work of the fifties in the field of nuclear engines for aircraft gave almost no result. It was possible to master a number of new technologies, but there was no intended result, as well as there were no full-fledged prerequisites for it.
In 1961, J. F. Kennedy, who immediately showed interest in promising aviation projects. Among others, documents on the projects of nuclear aircraft engines lay on his table, from which it followed that the costs of the programs were growing, and the result was still distant. In addition, by this time, ballistic missiles had appeared that could replace strategic bombers. Kennedy ordered to close all projects related to nuclear turbojet engines and to do less fantastic, but more promising things. As a result, the hypothetical plane, which Northrop Aircraft employees were engaged in determining the appearance, was left without engines. Further work in this direction was recognized as futile and the project was closed. The most ambitious project of an atomic aircraft remained at the stage of elaboration of the appearance.
