MiG 23UB / 23-51

The decision to build a two-seat trainer for the MiG-23 was made quickly: it was announced in a decree of the council of ministers dated 17 November 1967, fewer than six months after the prototype rollout However, the ministry’s directive went beyond a straightforward train­er and called for some sort of combat capacity—hence the designation UB (Uchebniy Boyevoi training-combat) Derived directly from the MiG-23S, the MiG-23UB was powered by the same engine, the R – 27F2M-300 rated at 6,760 daN (6,900 kg st) dry and 9,800 daN (10,000 kg st) with afterburner. The only structural modifications resulted from the rearrangement of the forward fuselage, the second cockpit taking the place of the equipment hay.

The ministry’s decree allocated the following missions to the new aircraft:

1. Day and night training in clear and adverse weather conditions to teach pilots how to take off, handle the full flight envelope with different types of weapons or dummy missiles, and land

2. Combat within the limits of the aircraft’s weaponry: the GSh-23L cannon, rockets, bombs, air-to-surface missiles (to attack ground or naval targets in visual mode), R-3S infrared-guided air-to-air missiles, or Kh-23 air-to-surface beam-rider guided missiles (since the two-seater had no radar, the latter’s guidance equipment was housed in small pods under the wing glove)

All of this weaponry (except the cannon) was carried under four store points: two under the fuselage and two under the wing glove. In the front cockpit, the student pilot’s equipment included the ASP-PFD fire control system (without the ranging device) and the weapon selec­tion panel. All other controls were duplicated, and the instructor’s set took priority. The nose was weighted to compensate for the lack of radar.

The MiG-23UB differed from the MiG-23S in many points:

1. Structurally, the nose section was modified up to the no. 18 bulk­head to make room for the second cockpit; the equipment bay and the standby hydraulic generator with its windmill were con­sequently moved back by reducing the capacity of fuel tank no. 1 —normally 7001 (185 US gallons)—and, to compensate, adding a tank in the rear fuselage to carry 470 1 (124 US gallons)

2. On-board equipment included the SOUA active angle-of-attack limiter (a few planes that were not so equipped used the SUA-1 critical AOA warning device and the R1S stick shaker), the UUA-1 attitude indicator, the Polyot-11-23 flight management system (including the RSBN-6S landing and short-range navigation device, the SKV-2N2 heading and vertical reference unit, and DV – 30/DV-10 signal transmitters) linked to the SAU-23UB automatic flight control system, three-axis artificial feel units and trims, radio-altimeter, automatic direction finder, marker receiver, the SORTS warning light display panel, IFF interrogator and transponder, radar warning receiver, the SPU-9 intercom, and the MS-61 tape recorder

The MiG-23UB wing, like that of the single-seater, "jumped” from type 1 to type 3. With the type 1 wing the MiG-23UB could carry only a single drop tank under the fuselage; but with the type 3 wing it could carry one drop tank under the fuselage and two drop tanks on non­swiveling pylons under the outer wings for ferry flights. The gear wheels all had brakes, and the two cockpits were equipped with KM-1

A MiG-23UB takes off for a ferry flight, ft has two drop tanks under the outer wmg pan­els. The 16-degree sweep setting will be maintained for the entire flight.

ejection seats and a centralized emergency abandonment system. A periscope was installed on the jettisonable part of the rear canopy so that the instructor could see more clearly while taking off, landing, and taxiing.

The MiG-23UB was rolled out in March 1969 and was first piloted in May by M. M. Komarov. The factory tests (carried out by Komarov and P. M. Ostapyenko) and the state trials lasted until 1970. That year the aircraft was approved for duty in WS and PVO fighter regiments, and it was produced in the Irkutsk factory until 1978.

Specifications

Span (72′ sweep), 7.779 m (25 ft 6.3 in); span (45° sweep), 11.928 m (39 ft 1.6 in); span (16° sweep), 13.965 m (45 ft 9.8 in); fuselage length (except probe), 15.66 m (51 ft 4.5 in); wheel track, 2.658 m (8 ft 8.7 in); wheel base, 5.772 m (18 ft 11.3 in); wing area (72° sweep), 34.16 m2 (367.7 sq ft); wing area (45° sweep), 35.5 m2 (382.1 sq ft); wing area (16° sweep), 37.35 m2 (402 sq ft); takeoff weight, 15,740 kg (34,690 lb); max takeoff weight, 18,000 kg (39,670 lb); landing weight, 12,400 kg (27,330 lb); fuel, 4,000 kg (8,815 lb); with three 800-1 (211-US gal) drop tanks, 6,350 kg (13,995 lb); wing loading (72° sweep), 460.8-526.9 kg/m2 (94.5-108 Ib/sq ft); wing loading (45° sweep), 443.4-507 kg/m2

The MiG-23M was built in the greatest numbers This one carries two R-60R and four R-60T air-to-air missiles.

(90.9-103.9 lb sq ft); wing loading (16° sweep), 421.4-481.9 kg/m2 (86.4-98.8 lb/sq ft); max operating limit load factor, 7.

Performance

Max speed in clean configuration (72° sweep), 2,490 km/h or Mach

2.35 at 12,500 m (1,344 kt at 41,000 ft); max speed in clean configura­tion at sea level (72° sweep), 1,200 km/h (648 kt); max operating Mach number, 2.35; max operating Mach number with four R-3S mis­siles, 2; max operating Mach number with four R-3S missiles and 800-1 (211-US gal) drop tank, 0.8; service ceiling, 15,800 m (51,825 ft).