Ye-152/1 / Ye 152/2

The Ye-152 represented the synthesis of two experimental prototypes: the Ye-150, test bed of the R-15-300 turbojet, and the Ye-152A, used to test the Uragan-5 automatic interception system and Mikoyan K-9 air – to-air missiles The Ye-152 was actually rolled out after the Ye-152A. On the recommendation of two test pilots, G. K. Mosolov and A. V.

This photograph shows the Ye-152/1 with a drop tank under the fuselage and, at the wing tips, models of the K-9 air-to-air missile under development

Fedotov, the new aircraft had a lower wing loading and better yaw sta­bility; the wing tip shakes and the aileron flutter were eliminated, and its taxiing conditions were improved. The new wing was larger thanks to a deeper tip chord, a modification that allowed missiles to be installed there. Its enhanced handling in ground maneuvers was due to a wider wheel track made possible by the modification of the wing structure. The yaw stability was rectified by increasing both the fin chord and area of the ventral fin so that the tail section could play a more efficient part in the tail fin’s work. The Ye-152 was designed to intercept and destroy on collision course any invader at 1,600 km/h at

10,0 m (864 kt at 32,800 feet) or 2,500 km/h at 20,000 m (1,350 kt at 65,600 feet) and beyond.

The diamond wing had a sweepback of 53 degrees, 47 minutes at the leading edge and a thin airfoil section (the thickness-chord ratio was 3.5 percent at the wing root and 5 percent at the wing tip). The triple-angle cone was fixed and made of dielectric material to house the radar antenna, like the Ye-150. Moreover, the Ye-152 had the same translating annular cowl as the Ye-152A. The cone’s annular base plate was perforated to bleed the boundary layer in order to increase the total pressure recovery factor at the compressor inlet level. The sole airbrake was located under the fuselage, and the container for the PT – 5605-58 tail chute was placed at the base of the ventral fin.

All flying controls were boosted by hydraulic servo-controls—two BU-65s for the slab tailplane, one BU-120M per aileron, and one BU – 120M for the rudder. The hydraulic system used AMG-10 fluid and could handle pressures of 210 atmospheres. The autopilot was the AP – 39. The total capacity of the fuel tanks in the fuselage and wing was 4,960 1 (1,310 US gallons), and a PB-1500 drop tank attached under the fuselage could carry another 1,500 1 (396 US gallons). In the event of ejection the pilot was protected by the cockpit hood. The R-15-300 tur­bojet of the Ye-152 was slightly more powerful than that of the Ye-150: 6,750 daN (6,800 kg st) of dry thrust and 10,005 daN (10,210 kg st) with afterburner. The Ye-152, like the Ye-150, was equipped with an ejector.

The first prototype or Ye-152/1 was moved to the test center on 16 March 1961. For the first flight by G. K. Mosolov on 21 April, provisional ballast of 263 kg (580 pounds) was placed in the nose. Tests continued until 8 January 1962, started up once more on 2 March, and were fin­ished by 11 September; sixty-seven flights were made—fifty-one with launching rails, five with missiles, and eleven in clean configuration.

The second prototype or Ye-152/2 took advantage of all the adjust­ments made during the Ye 152/1 tests and was significantly modified in two ways (1) to expand the pitch stability margin, the fuel tanks’ uti­lization sequence was altered – and (2) the boundary layer bleed device was improved by increasing the area of the perforated cone base plate. The flight envelope of the Ye-152/2 was tested up to a speed of 2,740 km/h (1,480 kt) at 22,500 m (73,800 feet) under clean conditions, and as far as Mach 2.28 at 18,000 m (59,000 feet) with K-9 missiles attached to the wing tips Flying the Ye-152/2 proved to be very similar to flying the Ye-152/1 But cancellation of the Ye-152/1 tests as well as those of the K-9 missile sealed the fate of the Ye-152/2. Only 60 percent of its test schedule was completed.

Specifications

Span, 8.793 m (28 ft 10.2 in); overall length (except probe), 19.656 m (64 ft 5.9 in); fuselage length (except cone), 16.603 m (54 ft 5.7 in); wheel track, 4.2 m (13 ft 9,4 in); wheel base, 6.265 m (20 ft 6.7 in), wing area, 42.02 m2 (452.3 sq ft); empty weight, 10,900 kg (24,025 lb); takeoff weight, 14,350 kg (31,630 lb); max takeoff weight, 14,900 kg (32,840 lb), fuel, 4,150 kg (9,145 lb), wing loading, 341 5-356.6 kg/m2 (70-73.1 lb/sq ft).

Performance

Max speed, 2,510 km/h at 10,000 m (1,355 kt at 32,800 ft); 3,030 km/h at 15,400 m (1,636 kt at 50,500 ft); climb to 10,000 m (32,800 ft) in 3 67 min; to 20,000 m (65,600 ft) in 5.33 min; service ceiling, 22,670 m (74,360 ft); landing speed, 260-270 km/h (140-146 kt); range with one

271

At the wing tips of this Ye-152P are models of the new R-4 air-to-air missile under development.

1,500-1 (396-US gal) drop tank, 1,470 km (915 mi); takeoff roll with two K-9s, 1,185 m (3,885 ft); landing roll, 1,270-1,300 m (4,165-4,265 ft).