REINCARNATION (su-7 to su-7БКЛ)

— in addition to the two guns NR-30 with ammunition for 65 cartridges per set 4 removable beam holder (two under the fuselage and two under the wing), which could be suspended: 4 bombs from 100 to 500 kg; 4 incendiary tank BZ-360; 4 missiles ARS-240 or ARS 212 to ПУ12-40; 28 missiles KARS-160 4 UBA-14, 64 57mm rockets ARS-57M or KARS-57 meters in 4 blocks of UB-16-57. For firing the guns and rockets used a modified sight ASP-5 NM, working in conjunction with DME SRD-5M, located in the radio waves cone air intake;

 

— to make full use of maximum takeoff angles and ensuring the departure from the land at minimum speed on the C-22-2 set a higher main landing gear and wheels CT-69 (880×230 mm) with disc brakes.

 

Basic flight data airplanes C-22 received during the state tests, meet the tactical-technical task, with the exception of the range (80 and 87% from the target at low and high altitudes, respectively).

 

 

 

 

Fly in the ointment to the obvious advantages of the new aircraft speed, twice the speed of sound, large range of payload of 2 tons and features the development of combatant plane pilots of average skill — were the deficiencies identified during the tests. Some of them were required to liquidate in the next three months, the rest had to be eliminated according to the program agreed by the State Committee on aviation technology (GKAT) and the Soviet air force.

 

The establishment of the first domestic fighter-bomber proved to be more difficult than seemed at first Combat use of the su-7B as a fighter-bomber in the brought to the test the limit the following disadvantages.

 

Shooting NAR was allowed to conduct only when the engine is idling because of the risk that it will stall.

 

Navigation equipment of the aircraft did not provide accurate output in the target area at low altitude. Air force Institute proposed to establish a course system of KSI instead of the gyro compass GIK-1, the errors of which after perform turns with roll more than 30° and change the speed of the flight reached 15 — 20°. Distorted information sent to the navigation indicator NI-50ИМ. Of error and big the graduation NO-50ИМ were not allowed to enter the goal: side the error was 5 — 6 km. In some cases, the aircraft flying at an altitude of 300 — 500 m, it was possible to direct on a target at a distance of 70 km, using ground-based radar P-30.

 

Flying at a low altitude test of the Institute revealed that the limited forward visibility is getting worse and optical effects — interaction of the reflector sight and the windshield glass due to the diffraction of light to the front of the plane viewed through the bright circular spot, which hinders the orientation and target detection. When flying in the direction of the sun review was practically absent. Height detection and recognition is an overlook of the guidelines was carried out through the side cockpit glass.

 

The state tests of the aircraft showed no stipulated technical requirements of the devices that bombing from horizontal flight and kupirovaniya. The sight ASP-5 NM was allowed to bomb only with a gentle dive, maintaining a pre-specified conditions of bombing (height, speed, and dive angle) the Angle of pre-emption was not to exceed 7.5° (otherwise the brand of sight was applied to LDPE and at an angle of more than 9° precision bombing is practically excluded). The very sight of the test did not work: their contribution to it made the sensor angles of attack and slip DUAS-133 DME and SRD-5.

 

In preparation for the state tests on the main landing gear C22-2 installed wheels with the air pressure in the tire 13 ATM — the biggest at that time in the domestic fighters. Due to low performance on earth the airfield for take-off the aircraft required special training runway. In addition, the su-7B was able to operate from airfields with a runway length of not less than 2.2 km away. During takeoff (the engine of the aircraft at takeoff and at the beginning of the run) fully compresses the shock absorber of the nose landing gear, and the distance from bottom of intake to the soil amounted to 930 mm on clay airfield would lead to entrainment of foreign objects and engine damage.

 

The engine AL-7F-1 due to design limitations and the lack of the automatic maximum speed limiter after the launch required constant attention, reducing the possibility of combat maneuvering of the aircraft and complicating the work of the pilot.

 

Stability and handling of the su-7B without-and with all brought to the test weapons were assessed as satisfactory. The disadvantages of the aircraft carried small quantities of efforts and deviation control knobs to create overload at subsonic speeds (in some flight regimes to increase the overload on a single unit of the handle was 3 mm), which could lead to dangerous consequences in combat. Because of this, experienced test pilots in some cases exceeded the specified maximum overload. There is increased sensitivity of the aircraft to deflection of the rudder and the large easy foot control with the lack of effectiveness of the ailerons. These deficiencies in piloting failed to clear in the future. The well-known military test pilot E. M. Groves assessed the flying of the su-7U in one sentence: “the awl”.

 

Of the five types of RS stipulated in the technical specifications, the state tests showed only two ARS-240 (later C-24) and KARS-57 (P-5K). In the Arsenal of the fighter was absent guided missiles “air — air”, so air force Institute proposed to rearm aircraft missiles K-13. The aircraft is stipulated in the technical specifications the 30 mm gun TKB-515 left cannon NR-30. Vitality cannon be below the established air force standards: front mount left gun collapsed after performing half of the required shots.

 

A flight with a set of practical ceiling in one direction was unsafe: deleting from the airfield up to 200 km remaining fuel in 600 — 800 kg are not guaranteed return to their base. Air force Institute proposed to further increase the capacity of the fuel system through the installation of two PTB under the wing.

 

Depending on take off weight speed of lift-off, the su-7B was 330 — 380 km/h. due to the large time of the landing gear (12 — 15) climb performed with increased angle of attack, to avoid exceeding the limit speed (< 600 km/h) to complete the landing gear.

 

In addition, the su-7B was proposed to set the autopilot to consider issues of suspension under the aircraft increased the number of NAR and aerial bombs of calibre of 100 and 250 kg. to increase the flight range of the aircraft ferry PTB increased capacity; to create on the basis of the su-7B training and combat aircraft. Lapping plane to the level of requirements that meet the air force took several years.

 

Fighter-bomber su-7B was adopted on 24 January 1961 and asked the development of modifications with improved landing performance and combat training. By this time in Komsomolsk-on-Amur was built 107 production su-7B.

 

First to the development of the su-7B began in June 1960 the pilots of the Voronezh regiment of the 4th Center for combat training and retraining of pilots of tactical aviation (tsbp and PLS). For the Voronezh production su-7B armed regiments IBA in the European part of the USSR: 642-y OAPI 48th VA Odessa military district, 274-th Proskurov APIB 9th IAP, VVS Moscow military district. From January to October 1961 in the 4th tsbp and PLS conducted combat tests of the su-7B, and 9 Jul 1961 21 serial fighter-bomber flew in the parade in Tushino.

 

To improve the landing characteristics of one of the su-7B (Cypher OKB-25) equipped with a control system pornsleep UPS-2M hardpoints boosters, 2-ku-dipole parachute system and automatic cleaning of the flaps, combined with the production of braking parachutes. December 2, 1961 test pilot OKB S. V. Ilyushin made the first flight on this machine.

 

In early 1962 s-25 modified: moved the drag chute container in the upper part of the fuselage and improve the system of blowing boundary layer.

 

Tests-25 system UPS-2M in early 1963 showed that the UPS does not provide the necessary reduction of the landing speed of the aircraft, increases the weight and complicates the operation and driving technique. The application of the system oops on the su-7B was acknowledged unreasonable.

 

Serial production of su-7B its design has been continuously improved. On the su-7B with the 13th series began to establish a system of KS-1 that, regardless of the position of lever engine control transferred to the latter at low throttle when pressing the pilot button combat with the launch of rockets, after which it automatically outputs the engine to the original mode. 26-series su-7B began to produce the main landing gear, shortened to 113 mm, and the eighth machine 31 series nose strut, complete with improved damping performance. On the rear fuselage with the 28th we came to the intakes blowing the flaps of a jet nozzle. Fighters with 36 series shifted to the starboard side rod LDPE, which significantly expanded the range of angles of dive when bombing and improved visibility from the cockpit forward on takeoff and landing. On the proposal of the technology of the production plant electroplaits put in two small fairing on the upper surface of the fuselage.

 

In early 1962, he graduated from the factory and have started joint state tests of modified su-7B (S-22-4) with a reduced length of run and run, equipped with wheel-ski gear. Factory tests have shown that the C-22-4 provides the pre-set technical specifications length of run and run.

 

The main characteristics of the aircraft su-7B

 

 

Note. Maximum takeoff weight for the given machine after the modernization program, adopted after the exercise “Dnepr-67”.

 

In July 1962, the Assembly line plant in Komsomolsk-on-Amur rolled out last serial fighter-bomber su-7B 45 series, and in September gathered the first fighter-bomber su-7BM (product-22M). Its production lasted until March 1965 when, after completing a 56 series switched to production of the su-7БКЛ.

 

For serial su-7BM implemented the main proposals highlighted in the act state testing of C-22 in may 1960:

 

— installed new equipment: the system of KSI-2, rsiu-5, the autopilot AP-28-T1, dual channel damper Д2К-110, the radio altimeter low altitude RV-UM, remote attitude indicator AGD-1;