Suchoj Su-7BKL [kód NATO: Fitter-A]

Due to the escalating international situation in the 50s and 60s, the Air Force was looking for a new more powerful tactical bomber capable of conducting nuclear attacks, which in the role of a tactical nuclear bomber could replace older aircraft Il-28. In the end, it was decided to create this bomber by modernizing the existing production series Su-7. The basis was taken by the kite Su-7BM. The volume of fuel tanks was increased and the original number of 4 weapon hangers was expanded to 6 (two hangers were added under the wing), while in the event of nuclear attacks, fuselage hangers were dismantled and replaced by a single central hanger with an adapter for tactical nuclear bomb.


Due to the need to carry out nuclear strikes from a safe distance from the target, it was decided that these attacks will be carried out in a 45 ° incline. In order to guarantee the maximum accuracy of these strikes, the existing criticized aiming system of the aircraft Su-7BM was replaced by a new weapon computer PBK-2. This computer was able to accurately calculate the time for dropping bombs on the climb and thus reduce the load placed on this pilot maneuver.


Because it was anticipated that these aircraft would have to operate from unpaved take-off areas, the aircraft landing gear was equipped with wheels with new wider low-pressure tires and supplemented with hydraulically extendable rails, which commanded from the cabin to extend 1.5 cm above the lower wheel level to prevent its engagement and detachment. After these modifications, the landing gear was, of course, thicker than the depth of the main landing gear shafts in the wings. This problem was eventually solved by the reconstruction of the covers of the chassis shafts on which the characteristic bulges covering the skis appeared. All these modifications were reflected in the higher weight of the aircraft and its greater dullness in acrobatics. This bluntness was also contributed by a modified way of controlling the brake pads of the aircraft when the original was continuous (as long as the button was pressed on the POM, the tags were ejected and kept open, after release the tags automatically retracted) control system replaced by a two-position system when there was only position full retraction or full extension of the labels. Therefore, the Su-7BKL aircraft were not very popular in training and acrobatic demonstration and for these occasions were replaced by aircraft Su-7BM.

We flew versions Su-7BM and Su-7BKL. There are, of course, more differences between them, but the most striking are the following:


1) Addition of another pair of hangers on the wings (load capacity 250 kg), ie extension of the original total number of four hangers (two under the fuselage, two under the wings, each with a load capacity of 500 kg) to 6 (two under the fuselage, four under the wings)


2) Installation of hydraulically operated skis on the main landing gear legs for the possibility of landing on untreated and soft landing areas (skis moved to a level of approximately 1.5 cm from the underside of the wheel and prevented the wheel from falling too far into the landing area)


3) Use of wider tires for landing on unpaved surfaces


4) A case for two ribbon braking parachutes was added to the lower part of the SOP (originally they were placed in a box under the fuselage)


5) Possibility of dismantling fuselage hangers and replacing them with a single central hanger with an adapter for carrying a tactical nuclear bomb


6) Change of the method of control of brake shields when the original was continuous (shields extend after pressing and holding the button for control of brake shields on POM, after its release they are automatically retracted) control of their extension changed to two-state (full extension or retraction without intermediate positions). was later criticized for making group and demonstration flying difficult.


7) Installation of a new aiming computer to facilitate bombing at an altitude of 45 ° (for use in nuclear strikes) and 125 ° (so-called bombardment over the shoulder).

Su-7BKL ("red 15"), Central Museum of the Air Force of the Russian Federation, Monino, 2006.

Su-7BKL s evidenčním číslem 6427 v leteckém muzeu ve Vyškově (fotografie ©Radek Havelka).

Su-7BKL čs.letectva



Zdroj : archív autora ( Propagačný materiál na nástenky ... )

Su-7BKL 65?? the czechoslovak air force, to the left is a visible cistern CAPL-15.

Author: Jindra Halásek

Source:
http://www.leteckemotory.cz/pilot/[/resources].