In 1951. at the Ilyushin Design Bureau, an experienced Il-46 bomber was designed and built, which retained the Il-28 scheme, but with twice the take-off weight and noticeably increased dimensions. The power plant of the Il-46 consisted of two AL-5 engines.
Ilyushin reinsured himself by re-betting on the straight wing. The maximum speed of the Il-46 with a relatively low thrust-to-weight ratio was 928 km / h. Creating a bomber close to its intended purpose, the Tupolev Design Bureau chose a more advanced scheme with a swept wing and two powerful AM-3 engines. The Tu-16 aircraft had a higher speed, formidable for those times defensive armament (seven 23-mm cannons), a good bomb load (up to 9000 kg). It is not surprising that it was he who was adopted as a long-range bomber capable of striking continental theaters.
Starting to develop a new jet front-line bomber in accordance with the decree of the USSR Council of Ministers of December 1, 1952, S. V. Ilyushin drew conclusions from the unsuccessful participation in the Il-46 competition. The decision before S. V. Ilyushin set the task of increasing the speed to M = 1, 15 at an altitude of 4750 m, a practical range of 2400-2750 km, and enhancing the striking power. Based on the main parameters and numerous computational and experimental studies, two layout schemes have been developed. According to the first, it was a mid-wing with two AL-7 engines located in gondolas in the root parts of the wing, as on the Tu-16, and with a swept wing. The main wheels of a conventional tricycle landing gear were retracted forward in the direction of flight into the inter-spar space of the wing power box.
However, at the design flight speed, there was a large interference resistance of the engine nacelles, which reduced the aerodynamic quality and basic characteristics. The second layout of the aircraft was adopted in the fall of 1953. The aircraft had two A. M. Cradle AL-7 and was made according to the vysokoplan scheme with the usual low location of the horizontal tail. The sweep angle of the wing was a record 55 °, which had not been used on aircraft of this type before. (An interesting detail. On the Il-28 there was a wing of the same shape and recruited from the same profiles as the wing of the MiG-9. On the Il-54, a wing with a sweep worked out on the MiG-19 was used.) In accordance with the results of blowing in wind tunnels, the engines on this version, the aircraft was installed in gondolas, which, like on the first-born jet S. V. Ilyushin Il-22, were suspended on pylons under the wing. This placement of the engines reduced their drag at high transonic flight speeds.
In addition (thanks to the high-wing layout of the aircraft), the engine air intakes were located high above the runway and when working on the ground, the engines did not suck in foreign objects from its surface. Difficulties arose in the search for layout solutions for the retraction of the main landing gear. "They didn’t want to go into the clean thin wing of the cart with large-diameter wheels." I had to go for an unusual solution for the OKB - to use a bicycle chassis scheme. Note that at that time the bicycle chassis was a "fashionable hobby" of many aircraft designers (remember at least the M-4, B-52, Yak-25 and other machines). The total mass of the take-off and landing devices was less than in the case of three traditional struts. However, in relation to the bomber, the bicycle scheme created certain difficulties when taking off a heavy machine: the rear pillar had to be placed behind the bomb bay, far beyond the center of mass of the loaded aircraft, which required the pilot to apply great efforts to the control wheel. A more serious flaw in the cycling scheme was later revealed in the operation of large aircraft; it was associated with the difficulty of maintaining the direction of the takeoff run and run in a strong crosswind. The required flight range of the Il-54, taking into account the high specific fuel consumption and high thrust of the engines (7700 kgf in takeoff mode), could be obtained only by significantly increasing the stock of kerosene, and, consequently, with a larger take-off weight, while the thin wing of a large sweep had a low quality in takeoff and landing flight modes. All this led to an increase in the lift-off speed, landing speed and the required length of the runways. To facilitate the separation of the front support from the ground, a special mechanism was included in the design of the rear support, shortening it during the takeoff run. The aircraft "squatted", the angle of attack of the wing increased almost twice, and this made it possible to significantly reduce the length of the aircraft's takeoff run. The lateral stability of the Il-54 when moving on the ground was provided by auxiliary lateral supports at the ends of the wing, retractable into streamlined nacelles.
In the lower part of the fuselage there were cutouts for a radar antenna, bomb bay, landing gear compartments. The aircraft's crew consists of three people: a pilot, a navigator and a stern gunner-radio operator, located in two (front and rear) pressurized cabins. The pilot and navigator entered the plane through a small door on the starboard side of the fuselage, and the gunner through the lower hatch of their cockpit. There was a passage between the cockpits of the navigator and the pilot, which allowed them to communicate with each other in flight. All crew members' workplaces had strong armor protection. In the event of an emergency in flight, the crew could leave the aircraft using ejection seats, while the pilot ejected upward, and the navigator and gunner down. In the event of an emergency landing on water, all crew members could leave the aircraft through the upper hatches of their cabins and use the automatically ejected LAS-5M rescue boat.
Defensive armament included three 23-mm AM-23 cannons, which have a high rate of fire and the power of a second salvo. An immobile cannon located on the left side of the fuselage protected the front hemisphere. In the aft remote-controlled turret there were two movable guns. The maximum bomb load of the Il-54 aircraft is 5000 kg. The aircraft's armament and equipment ensured its effective use in front-line conditions against enemy military equipment, manpower and vehicles, made it possible to use it to destroy strongpoints and engineering structures located on the battlefield and in the tactical depth of the enemy's defense when acting as part of formations. and single aircraft from all heights in opposition to fighter aircraft and ground-based air defense of the enemy, in any meteorological conditions day and night.
Due to the unavailability of the engines, which were painfully brought to the A. M. Cradle, the construction of the aircraft was delayed. Factory flight tests of the IL-54 were carried out by the crew headed by V. K. Kokkinaki. According to him, the aircraft showed good stability and controllability in flight. But takeoff and landing were to a certain extent complicated by the use of a bicycle-type chassis. The first flight of the new front-line bomber took place on April 3, 1955. Further, the usual sequence of elimination of small and large defects of the machine and its systems began. Note that the AL-7 engine at that time was in great demand: with the expectation of it, various aircraft design bureaus designed about a dozen aircraft. The highest priority was given to P. O. Sukhoi, whose design bureau received at its disposal almost all copies of the AL-7 suitable for flight.
In the spring of 1956, the Il-54 crashed while landing with a crosswind. Even such an experienced test pilot as V. K. Kokkinaki, failed to keep the car on the lane. By this time, the construction of the second prototype Il-54 was completed with two modified AL-7F engines, the takeoff thrust of which in the forced mode was increased to almost 10 tf. S. V. Ilyushin decided to demonstrate it to the leadership of the Ministry of Defense before sending the vehicle for testing. In June 1956, two front-line bombers, the old Il-28 and the new Il-54, were installed side by side on a concrete site near the gates of the assembly shop of the pilot plant. The picture turned out to be impressive: the new car was distinguished by much more rapid forms, but it was much larger than the old one both in size and weight.
Defense Minister Marshal of the Soviet Union G. K. Zhukov. He listened to the report and carefully examined the new aircraft. But the reaction was not at all what the organizers of the "show" expected. Zhukov, pointing to the accompanying military, first at the Il-28, and then at the Il-54, expressed his attitude with just two phrases: "This is a front-line bomber! Is this a front-line bomber?" And, without listening to any explanations, the minister got into the car and drove away from the airfield. After this incident, the Il-54 made several more flights. However, the negative opinion of the minister actually put an end to him. S. V. Ilyushin painfully took this second blow from the leadership of the Ministry of Defense (several months earlier, the same G. K. Zhukov made a decision to eliminate the attack aircraft and to abandon the Il-40 jet attack aircraft created by the Ilyushinites). The creation of the Il-54 aircraft was completed, which was carried out under the leadership of S. V. Ilyushin's long-term work of the OKB team on manned bombers.
Technical data of IL-54:
Crew - 3 people.
The maximum take-off weight is 38,000 kg.
Dimensions: length x height x wingspan - 21, 80 x 6, 40 x 17, 80 m.
Power plant: number of engines x power - 2 AL-7 x 5000 kgf.
Maximum flight speed: at an altitude of 5000 m - 1250 km / h.
Climb rate: to a height of 5000 m - 4 min.
Service ceiling - 14,000 m.
Flight range - 2,400 km.
Armament: 3 cannons NR-23.
Maximum bomb load - 5000 kg
