Tu-154 Careless

The Tupolev Tu-154, NATO reporting name Careless, is a three-engined medium-range narrow-body airliner designed in the mid-1960s and built until 2013, with 1,025 completed. It was the workhorse of Soviet and then Russian aviation for three decades, at one point carrying half of all passengers flown by Aeroflot and its subsidiaries — 137.5 million a year, or 243.8 billion passenger-kilometres, in 1990 — and it remained the standard domestic airliner across the former Soviet Union until the mid-2000s. Exported to seventeen non-Russian airlines, it also served several air forces as a head-of-state and staff transport, and it is in that military role that surviving aircraft still fly.

Development

The Tu-154 was designed to meet an Aeroflot requirement to replace three types at once: the jet-powered Tu-104 and the An-10 and Il-18 turboprops. The specification called for either 16 tonnes of payload over 2,850 km or 5.8 tonnes over 5,800 km, at cruising speeds of 900 km/h, with a take-off run of 2,600 m at maximum weight. Conceptually the aircraft resembled the British Hawker Siddeley Trident of 1962 and the American Boeing 727 of 1963, and Tupolev marketed it against Ilyushin's long-range Il-62. The Soviet Ministry of Aircraft Industry chose the Tu-154 as the design that best matched Aeroflot's expected needs for the 1970s and 1980s.

The prototype first flew on 4 October 1968. Deliveries to Aeroflot began in 1970, mail services in May 1971 and passenger services in February 1972. Limited production of the Tu-154M continued far beyond the nominal 2006 end of manufacture; the last serial aircraft was delivered to the Russian Defence Ministry on 19 February 2013 from the Aviakor plant with upgraded avionics, a VIP interior and a communications suite.

Design

Three rear-mounted low-bypass turbofans are arranged as on the Boeing 727, with an S-duct feeding the centre engine, on an airframe slightly larger than its American counterpart. Early aircraft used Kuznetsov NK-8-2 engines; the definitive Tu-154M switched to the more efficient Soloviev D-30KU-154 of 10,500 kgf each, which together with aerodynamic refinement cut fuel consumption and extended range. The high thrust-to-weight ratio gave the type excellent field and climb performance at the cost of fuel efficiency, a trade that mattered increasingly as fuel prices rose.

The wing is swept 35° at quarter chord and has anhedral, a distinguishing feature of Soviet low-wing airliners of the period; Western contemporaries generally used dihedral. The anhedral reduces lateral stability but improves resistance to Dutch roll. Considerably heavier than the Il-18 it replaced, the Tu-154 was given oversized landing gear to keep ground loading low enough to use the same runways: two six-wheel main bogies on large low-pressure tyres retract into pods extending aft of the wing trailing edges, in the Tupolev manner, and soft oleo struts give a notably smooth ride on rough surfaces. That combination made the aircraft usable from unpaved and gravel strips and, in practice, indispensable in the Arctic conditions of northern and eastern Russia where no other airliner could operate.

The original three-person flight crew of captain, first officer and flight engineer soon had to be supplemented by a navigator, whose station was compromised by the constraints of the original design. Early variants cannot be brought up to Stage III noise standards and are barred from European Union airspace; the Tu-154M's D-30 engines can be hush-kitted and remain compliant.

Operational History

The Tu-154 was designed for a 45,000-hour service life over 18,000 cycles, extensible to 80,000 hours with upgrades. At its peak it was the backbone of Aeroflot's domestic network and of most Comecon flag carriers. Retirement from civil service accelerated through the 2000s under noise restrictions, rising fuel costs and safety concerns; 214 aircraft were still flying at the end of 2009, and Russian airlines have since withdrawn the type almost entirely.

Military and government operators kept it longer. Air forces across the former Soviet Union and its allies used the Tu-154 as a VIP and staff transport, and specialised versions were built for other duties, including Chinese Tu-154MD electronic intelligence aircraft carrying a large synthetic-aperture radar under the fuselage. Russia also operated Tu-154M-ON aircraft on Open Skies treaty observation flights before replacing them with the Tu-214ON.

Variants

• Tu-154 — initial production from 1970 with NK-8-2 engines and 164 seats; about 42 built.
• Tu-154A — 1974 upgrade with centre-section fuel tanks, more emergency exits and higher-thrust NK-8-2U engines.
• Tu-154B — 1975 version with a stronger wing after the early aircraft suffered wing cracks, plus an extra fuselage fuel tank and higher maximum weight; most earlier aircraft were rebuilt to this standard. The B-1 and B-2 subvariants followed, the B-2 certified for a three-person crew and built in the largest numbers, some 311 aircraft.
• Tu-154S — an all-cargo conversion with a strengthened floor and a forward port-side cargo door; nine converted, all retired by 1997.
• Tu-154M — the definitive version, first flown in 1982 and in production from 1984, with D-30KU-154 engines, double-slotted flaps with an extra 36° setting for quieter approaches, a relocated APU and a higher maximum take-off weight. About 320 were built.