Tupolev Tu-154

Development

The Tu-154 was developed to meet Aeroflot's requirement to replace the jet-powered Tu-104 and the Antonov An-10 and Ilyushin Il-18 turboprops. The requirements called for either a payload capacity of 16–18 t (35,000–40,000 lb) with a range of 2,850–4,000 km (1,770–2,490 mi; 1,540–2,160 nmi) while cruising at 900 km/h (560 mph; 490 kn), or a payload of 5.8 t (13,000 lb) with a range of 5,800–7,000 km (3,600–4,300 mi; 3,100–3,800 nmi) while cruising at 850 km/h (530 mph; 460 kn). A take-off distance of 2,600 m (8,500 ft) at maximum takeoff weight was also stipulated as a requirement. Conceptually similar to the British Hawker Siddeley Trident, which first flew in 1962, and the American Boeing 727, which first flew in 1963, the medium-range Tu-154 was marketed by Tupolev at the same time as Ilyushin was marketing its long-range Ilyushin Il-62. The Soviet Ministry of Aircraft Industry chose the Tu-154, as it incorporated the latest in Soviet aircraft design and best met Aeroflot's anticipated requirements for the 1970s and 1980s.

The first project chief was Sergey Yeger; in 1964, Dmitryi S. Markov assumed that position. In 1975, the project lead role was turned over to Aleksandr S. Shengardt.

The Tu-154 first flew on 4 October 1968. The first deliveries to Aeroflot were in 1970 with freight (mail) services beginning in May 1971 and passenger services in February 1972. Limited production of the 154M model was still occurring as of January 2009, despite previous announcements of the end of production in 2006. In total, 1025 Tu-154s have been built, 214 of which were still in service as of 14 December 2009. The last serial Tu-154 was delivered to the Russian Defense Ministry on 19 February 2013 from the Aviakor factory, equipped with upgraded avionics, a VIP interior, and a communications suite. The factory has four unfinished airframes in its inventory, which can be completed if new orders are received.

Design

The Tu-154 is powered by three rear-mounted, low-bypass turbofan engines arranged similarly to those of the Boeing 727, but it is slightly larger than its American counterpart. Both the 727 and the Tu-154 use an S-duct for the middle (number-two) engine. The original model was equipped with Kuznetsov NK-8-2 engines, which were replaced with Soloviev D-30KU-154s in the Tu-154M. All Tu-154 aircraft models have a relatively high thrust-to-weight ratio, giving the type excellent performance, though at the expense of lower fuel efficiency. This became an important factor in later decades as fuel costs grew.

The cockpit is fitted with conventional dual yoke control columns. Flight control surfaces are hydraulically operated.

The cabin of the Tu-154, although of the same six-abreast seating layout, gives the impression of an oval interior, with a lower ceiling than is common on Boeing and Airbus airliners. The passenger cabin accommodates 128 passengers in a two-class layout and 164 passengers in single-class layout, and up to 180 passengers in high-density layout. The layout can be modified to a winter version where some seats are taken out and a wardrobe is installed for passenger coats. The passenger doors are smaller than on its Boeing and Airbus counterparts. Luggage space in the overhead compartments is very limited.

Like the Tupolev Tu-134, the Tu-154 has a wing swept back at 35° at the quarter-chord line. The British Hawker Siddeley Trident has the same sweepback angle, while the Boeing 727 has a slightly smaller sweepback angle of 32°. The wing also has anhedral (downward sweep) which is a distinguishing feature of Russian low-wing airliners designed during this era. Most Western low-wing airliners such as the contemporary Boeing 727 have dihedral (upward sweep). The anhedral means that Russian airliners have less lateral stability compared to their Western counterparts, but also are more resistant to Dutch roll tendencies.

Considerably heavier than its predecessor Soviet-built airliner, the Ilyushin Il-18, the Tu-154 was equipped with an oversized landing gear to reduce ground load, enabling it to operate from the same runways, including limited gravel capability. The aircraft has two six-wheel main bogies fitted with large, low-pressure tires that retract into pods extending from the trailing edges of the wings (a common Tupolev feature), plus a two-wheel nose gear unit. Soft oleo struts (shock absorbers) provide a much smoother ride on bumpy airfields than most airliners, which very rarely operate on such poor surfaces.

The original requirement was to have a three-person flight crew – captain, first officer, and flight engineer – as opposed to a four- or five-person crew, as on other Soviet airliners. A fourth crew member, a navigator, was soon found to be still needed, and a seat was added on production aircraft, although that workstation was compromised due to the limitations of the original design.