The Yakovlev Yak-18T

Country of origin
Russia

Type
Four seat light aircraft
History
One of the very few four seat light aircraft to be built in the Soviet Union during the Cold War years, the rugged Yak-18T has its basis in the Yak-18 series of two seat trainers.
The Yak-18 first flew in 1946 and went on to be built in massive numbers (including more than 8000 for the Soviet air force which used it as its standard military basic trainer for many decades). Most production was of the Yak-18A. Several single seat models were built for competition aerobatics, including the Yak-18P, Yak-18PM and Yak-18PS. Many have since appeared in the west.
The four seat Yak-18T was the last production model, and the most extensively modified. Compared with the single and two seat Yak-18 models, the Yak-18T introduced a much enlarged cabin with seating for four, tricycle undercarriage (single seat Yak-18PMs had tricycle undercarriage also), plus the 265kW (355hp) Vedneyev (now VOKBM) M14 nine cylinder radial engine.
First flight occurred in mid 1967 and the Yak-18T was then subsequently placed in series production in Smolensk. The Yak-18T went on to become the standard basic trainer with Aeroflot flight schools, while small numbers also entered service with the Soviet air force as liaison and communications aircraft. After approximately 200 were built, mainly for Aeroflot, production ceased in the late 1980s.
In 1993 the Smolensk Aircraft Factory placed the -18T back into production against a number of new contracts, including 20 for the Philippines air force. Several Yak-18Ts have also found their way into the west.
Meanwhile Technoavia offers its own development of the Yak-18T, the SM94, but production is dependant on orders being placed.
Compared with western four seat light aircraft, the Yak-18T is much larger, heavier and less economic to operate with a far more powerful engine, although it was never intended for private pilot operation. Its strong construction and military background has given it an aerobatic capability, while its general handling characteristics are docile.

Powerplants
One 265kW (355hp) Vedneyev/VOKBM M14P nine cylinder radial piston engine driving a two blade variable pitch metal propeller.
Performance
Max speed 295km/h (159kt), max cruising speed 250km/h (135kt), economical cruising speed 210km/h (113kt). Initial rate of climb 985ft/min. Service ceiling 18,120ft. Range with four people, max fuel and reserves 580km (313nm).
Weights
Empty 1217kg (2683lb), max takeoff (with four people) 1650kg (3637lb).
Dimensions
Wing span 11.16m (36ft 7in), length 8.39m (27ft 7in), height 3.40m (11ft 2in). Wing area 18.8m2 (202.4sq ft).
Capacity
Typical seating for four in touring role, often used as a trainer with two on board.
Production
Estimated Yak-18T production of 200, with more than 150 still in service in Russia. Production initially ceased in 1989, but resumed by the Smolensk Aircraft Factory in 1993.

The Yakovlev Yak-40

Country of origin
Russia

Type
Regional jet airliner
History
The Yak-40 was the first jet powered airliner in its class in service in large numbers anywhere in the world, preceding the ERJ-135 and 328JET by three decades.
Design of the Yak-40 resulted from a mid 1960s Aeroflot requirement for a replacement for the thousands of Lisunov Li-2s (Soviet built DC-3s), Ilyushin Il-12s and Il-14s (described separately) then in service. Aeroflot attached great significance to the Yak-40 program, as the aircraft was intended to operate regional services that accounted for 50% of Aeroflot's passenger traffic.
A S Yakovlev (after whom the design bureau is named) led the Yak-40 design team, and the program's existence was revealed on October 21 1966, when the first prototype made its maiden flight. The type went into production in 1967 and entered service with Aeroflot in September 1968. Production continued until 1978, with 1011 built by the Saratov aircraft factory, of which 125 aircraft were exported to 18 countries.
The Yak-40's most noticeable design feature is its trijet configuration, with three specially developed Ivchenko AI-25 two shaft turbofans. The three jet engine layout was chosen for increased redundancy (and hence better one engine out performance, allowing good short field performance). The unswept, high aspect ratio wing is also designed for good field performance. An APU and a ventral airstair in the rear fuselage allow autonomous operation at remote airfields. A high power-to-weight ratio allows the Yak-40 a good hot-and-high performance - operating economics was a lesser priority.
The Yak-40 remained basically unchanged during its production life, but a number of developments were proposed, including the Yak-40M, a 40 seat stretched development. For a time a US company, ICX Aviation, planned to build the type in the USA with western avionics and three Garrett TFE731 turbofans. The Yak-40TL twin engine conversion was also proposed. The main difference would have been the replacement of the Yak-40's three engines with two Lycoming LF 507s.
The Yak-40K is a cargo-passenger version with a port-side forward cargo door with a maximum payload of 3200kg (7055lb) in all freight configuration.
The Yak-40D has two additional fuel tanks to increase the total fuel capacity to 6000kg (13,200lb). The Yak-40DTS is a troop carrier and paramedic configuration. Other versions are equipped for calibration, meteorological research, testing and inspecting of radio-electronic equipment, and for use as an engine testbed.
Apart from airliner use, a number are in service as corporate or government transports with a VIP interior.

Powerplants
Yak-40 - Three 14.7kN (3300lb) Ivchenko AI-25 turbofans.

Performance
Yak-40 - Max cruising speed 550km/h (297kt), economical cruising speed 470km/h (254kt). Range with max payload of 32 passengers 1450km (780nm), range with max fuel 1800km (970nm).Yak-40D - Range with maximum fuel and reserves 2200km (1185nm).
Weights
Yak-40 - Empty 9400kg (20,725lb), max takeoff 16,000kg (35,275lb).Yak-40D - max takeoff 17,200kg (37,920lb)
Dimensions
Wing span 25.00m (82ft 0in), length 20.36m (66ft 10in), height 6.50m (21ft 4in). Wing area 70.0m2 (735.5sq ft).
Capacity
Flightcrew of three (two pilots and engineer). Typical passenger seating arrangement for 27 at three abreast and 78cm (30in) pitch. Maximum seating for 32 in a high density four abreast configuration. Some fitted with corporate interiors with seating arrangements for 12-15 passengers.
Production
Total Yak-40 production is 1011, of which approximately 750 were built for Aeroflot. Approximately 490 remained in airline service in late 2000, others are used as corporate transports.

The Yakovlev Yak-42

Country of origin
Russia

Type
Short range airliner
History
The Yak-42 trijet was developed as a replacement for Tupolev's Tu-134 twinjet and Antonov's An-24 turboprop.
The Yak-42 is an all new design although, like the Yak-40, it features a three engine configuration for increased redundancy and good short field performance. A moderately swept wing was a compromise between the need for good field performance and high speed cruise capabilities. An integral airstair, APU and double main undercarriage are all incorporated into the Yak-42 design for austere airfield operations. The Lotarev turbofan meanwhile was one of the first true turbofans to be developed in the Soviet Union.
The first of three prototypes flew on March 7 1975. Development flying revealed the need for increased wing sweep back, and the change of wing sweep angle and suspected development problems with the new three shaft turbofans delayed service entry to late 1980.
Most production was of the initial Yak-42. The Yak-42D was introduced in 1989 and became the standard production model. It features increased fuel capacity, taking range with 120 passengers to 2200km (1185nm).
The Yak-42T is a freighter design study. It would be fitted with a main deck freight door, and capacity would be 12 tonnes.
The Yak-42D-100 meanwhile is a development with a four screen AlliedSignal EFIS cockpit among other improvements. One was displayed at the 1993 Paris Salon (as the Yak-142). A VIP/corporate jet development is also offered.
The Yak242 was an all new design study with the Yak-42's cross section, two PS90A turbofans and seating for up to 180.

Powerplants
Three 63.7kN (14,330lb) ZMKB Progress (Lotarev) D36 turbofans.
Performance
Yak-42 - Max cruising speed 810km/h (437kt), economical cruising speed 750km/h (405kt). Range with max payload and reserves 1380km (745nm), with 120 passengers 1900km (1025nm), with 104 passengers 2300km (1240nm), with max fuel and 42 passengers 4100km (2215nm). Yak-42D - Range with 120 passengers 2200km (1185nm).
Weights

Yak-42 - Empty equipped with 104 seats 34,500kg (76,058lb), with 120 seats 34,515kg (76,092lb); max takeoff 57,000kg (125,660lb). Yak-42D - Max takeoff 57,500kg (126,765lb).
Dimensions
Wing span 34.88m (114ft 5in), length 36.38m (119ft 4in), height 9.83m (32ft 3in). Wing area 150.0m2 (1614.6sq ft).
Capacity
Flightcrew of two pilots, with provision for a flight engineer. High density single class seating for 120 at six abreast and 75cm (30in) pitch. Two class seating for eight premium class passengers at four abreast and 96 economy class at six abreast.
Production
More than 180 built, with most delivered to Aeroflot and its successors. Approx 150 were in commercial service in 1998.