"By the way, Lu Suo, why did the Americans suddenly come to our place to investigate?"

Yang Weining wondered.

Lu Wenjun said with a smile: "They are mainly here for the Peace Model Project, and they have already inspected the 601 Institute before, so they just took it to us by the way." ”

"A model of peace?"

Yang Weining couldn't help but be stunned.

In the 80s of the 20 th century, the most commendable aspect of Sino-US aviation cooperation, in addition to the "Black Hawk" helicopter, was the "Model of Peace" program.

Since the split between China and the Soviet Union, relations between the two sides have gradually become tense, until the Zhenbao Island conflict, in which China and the Soviet Union have millions of troops near the border.

The pressure from the north has become the primary threat to China's national defense, since the 60s, a large number of new weapons and equipment of the Soviet Union have been equipped with troops, especially the Tu-22M backfire supersonic bomber is a particularly significant threat to China, which can penetrate the defense at a low altitude and high speed at a speed of 2M, take off from the Far East of the Soviet Union, the Central Asian part and Mongolia, and quickly strike at important targets in China's three northern regions.

The Chinese Air Force was equipped with J-6/7 fighters that year can not intercept it at all, although the J-8 has a certain interception capability, but due to its lack of perfect airborne avionics system, if the backfire is covered by bad weather, then China only relies on the Hongqi-2 air defense missile.

And it is difficult for such a stationary anti-aircraft missile to fully defend against such a flexible supersonic bomber over a wide area.

Therefore, since the 60s, China has needed a fighter capable of intercepting enemy bombers outside or on the edge of its airspace in all-weather conditions.

This is also the origin of the original J-9 program.

However, the J-9 fighter unrealistically raised the index to double three, that is, the so-called Mach speed at an altitude of 30,000 meters, which was impossible to reach the level of basic research in China's aviation industry at that time, which also led to the increasingly slow development of J-9 after the 70s.

In this case, at the end of the 70s, according to the needs of the army's weapons and equipment renewal in the mid-to-late 80s, combined with the development level of the world's fighters, China's aviation engineers put forward the idea of a major revision of the J-8, so as to provide the troops with fighters capable of intercepting high-altitude and low-altitude high-speed invasion targets in the 80s.

Since the most important mission of the new J-1 is to intercept the backfire bomber, this requires its supersonic performance to be good, and the advantages of the delta wing are that the aspect ratio is small, the shock wave resistance is small, the supersonic speed/transonic aerodynamic performance is better, the aerodynamic focus change is balanced, and the structural strength is also better.

In the case of insufficient overall aerodynamic technical reserves in China's aviation industry, the J-8II with a delta wing layout can better meet the design requirements.

However, the disadvantage of the delta wing is that the induction drag is large, and the endurance and maneuverability at subsonic speeds are not good.

Moreover, in order to intercept a backfire bomber, in addition to excellent flight performance, a complete avionics system is also essential, especially the pulse Doppler radar-PD radar with downward/downward firing capabilities.

The J-8II was originally prepared to be equipped with the 1471 radar developed by the 14 Institute, but at that time China's foundation in this field was almost blank, although the 1471 was not a full-waveform radar, only two kinds of pulse repetition rate, but its technical difficulty also made the radar engineers of the 14 Institute at that time daunting.

As a backup to the 1471 radar, the Changhong Plant also began to develop the 208 radar with interception capability on the basis of the 204. Despite its single-pulse fire control radar, it does not have the ability to look down/fire. However, the research and development work is still not smooth, and it can be said that there are many difficulties.

Under these circumstances, the Supreme Military Council decided to take advantage of the favorable international environment to solve the problem of backwardness of the J-8II supporting system by introducing advanced foreign systems.

This is where the Model Peace Project comes from.

From 1982 to 1987, China and the United States held several negotiations on the introduction of avionics systems, with Lockheed and Grumman in the United States competing.

Lockheed is the manufacturer of the F-16 fighter, and Grumman is the manufacturer of the F-14 Tomcat fighter.

In the end, after many comparisons, the Chinese side chose Grumman as the foreign general contractor, and the installation, inspection, testing and flight test of the aircraft systems were carried out at the company's Bispige plant in Long Island, New York.

THE RADAR IS THE AMERICAN AN/APG-66 RADAR, WHICH IS BASICALLY EQUIVALENT TO THE RADAR LEVEL ON THE AMERICAN F-16BLOCK15 BATCH.

The AN/APG-66 radar is divided into 7 replaceable parts, including antenna, transmitter, receiver, digital signal processor, computer and control system, with pulse Doppler and single pulse systems.

The working state includes air, up, down, combat and air-to-ground, of which the open-ground includes ranging, vacuum wave velocity mapping, Doppler beam sharpening, map freezing, auxiliary navigation and sea search and other functions.

In addition to the AN/APG-66, another important system of the fire control system uses the LN-39 inertial navigation system of Litton.

In fact, it is the standard inertial navigation system of the US Air Force, and the LN-3g system meets the requirements of the medium accuracy of the US Air Force F8 standard, that is, the system can be coordinated and interchangeable in terms of shape, function and adaptability, and the positioning accuracy is 0.8 knots per hour. The "heart" of LN-39 is the P-1090 inertial platform, which is the miniaturization of the P-1000 platform, and when the P-1000 platform components and system software in LN-37 are adopted, the accuracy of the P-1090 platform can be 0.2~0.3 nautical miles/hour, and the average fault illumination time of the platform is 2000 hours. The computer is LC-4516C type.

By replacing the input/output components or modifying the light parts, the LN-39 has increased its functions, such as integrated navigation (Doduler-inertial, in-flight alignment, ground positioning system-inertia, etc.) and auxiliary tasks such as maneuvering, fire control, and fuel management. Its backup is the attitude and course reference system.

In order to adapt to the improvement of the airborne fire control system, the cockpit of the improved J-8II has also been improved, using a new type of head-up display and multi-function display, in which the HUD field of view is 13*9 degrees, and the functions include displaying fire control system information and radar information, flight data and maneuvering energy management information include the display of radar target interception indication symbols when aiming at air-to-air, aiming aura, the maximum and minimum launch distance of missiles, aiming control points, projectile tracer lines (hot wires) and aircraft speed vectors (vv), etc.

In the air-to-ground aiming state, the attack screen using various air-to-ground weapons is displayed.

MFD is a high-resolution, high-brightness TV/raster display. Thanks to the advanced CRT technology and optical filtering technology, the MFD can produce a clear, high-contrast display image even in direct sunlight conditions, and the MFD can be used as a vertical display VSD. Alphabet and tabular displays and for air-to-ground guided weapons such as televisions.

Due to the improvement and expansion of the avionics system, the J-8II adopts the 1553B data bus.

The 1553B data bus is a military standard in the United States that appeared in the early 70s. Since then, the 1553B data bus has been dominant on most newly developed fighters. The main difference between the 1553B data bus and the previous data bus is that it is a multi-information source and multi-node data bus with a large capacity.

Its role is broadly similar to that of a series of multi-track railways, transporting "passengers" (i.e. data) to (or depositing) their respective destinations. On this basis, by improving the configuration and equipment of the fighter's avionics system, we can achieve the goal of extending the effective combat use time of the fighter with a relatively small amount of investment, so that it can compete with the new, more expensive fighter for a certain period of time.

In addition to the 1553B data bus, the J-8II also uses the F-16's central fire control computer, which includes the calculation of the front angle of the air-to-air cannon and the missile launch area. Air-to-ground attacks calculate weapon ballistics, impact points, aiming points, and maneuver commands. In addition to the above-mentioned equipment, other equipment of the Peace Model also includes: air data computer and database, plug-in management system, etc.