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. Navigators are no longer trained, and this profession is becoming obsolete with the retirement of the oldest Soviet-era planes. The latest variant (Tu-154M-100, introduced 1998) includes an NVU-B3
Doppler navigation system, a triple
autopilot, which provides an automatic ILS approach according to
ICAO category II weather minima, an
autothrottle, a Doppler drift and speed measure system, and a "Kurs-MP" radio navigation suite. A stability and control augmentation system improves handling characteristics during manual flight. Modern upgrades normally include modernised
TCAS,
GPS, and other systems (mostly American- or EU-made). Early versions of the Tu-154 cannot be modified to meet the current Stage III
noise regulations, so are no longer allowed to fly into airspace where such regulations are enforced, such as the European Union, but the Tu-154M's D-30 engines can be fitted with
hush kits, allowing them to meet noise regulations. ==Variants==
Tu-154 Tu-154B-1 Tu-154B-2 Tu-154M Many variants of this airliner have been built. Like its Western counterpart, the Boeing 727, many of the Tu-154s in service have been hush-kitted, and some converted to freighters. ; Tu-154 : Tu-154 production started in 1970, and the first passenger flight was performed on 9 February 1972. Powered by
Kuznetsov NK-8-2 turbofans, it carried 164 passengers. About 42 were built. ; Tu-154A : The first upgraded version of the original Tu-154, the A model, in production since 1974, added center-section fuel tanks and more emergency exits, while engines were upgraded to higher-thrust Kuznetsov NK-8-2U. Other upgrades include automatic flaps/slats and stabilizer controls and modified avionics. Max. takeoff weight – . There were 15 different interior layouts for the different domestic and international customers, seating between 144 and 152 passengers. To discern the A model from the base model note the spike at the junction of the fin and tail. This is a fat bullet on the A model, and a slender spike on the base model. ; Tu-154B : As the original Tu-154 and Tu-154A suffered wing cracks after a few years in service, a version with a new, stronger wing, designated Tu-154B, went into production in 1975. It also had an additional fuselage fuel tank, additional emergency exits in the tail. Also, the maximum takeoff weight increased to . Important to Aeroflot was the increased passenger capacity, hence lower operating costs. With the NK-8-2U engines the only way to improve the economics of the airplane was to spread costs across more seats. The
autopilot was certified for ICAO Category II automatic approaches. Most previously built Tu-154 and Tu-154A were also modified into this variant, with the replacement of the wing. Maximum takeoff weight increased to . 111 were built. ; Tu-154B-1 : Aeroflot wanted this version for increased revenue on domestic routes. It carried 160 passengers. This version also had some minor modifications to the fuel system, avionics, air conditioning, and landing gear. 64 were built from 1977 to 1978. ; Tu-154B-2 : A minor modernization of Tu-154B-1, equipped with navigation systems capable of cooperating with Western systems. Can be flown by a three-person crew – pilot, copilot and flight engineer –, due to the requirement of
Malév (the Soviets insisted on keeping four or five person flight crews, while Malév deemed this economically inapprovable). The airplane was designed to be converted from the 160-passenger version to a 180-passenger version by removing the galley. The procedure took about hours. Some of the earlier Tu-154Bs were modified to that standard. Maximum takeoff weight increased to , later to . Some 311 aircraft were built, including VIP versions. A few remain in service. ; Tu-154S : The Tu-154S is an all-cargo or freighter version of the Tu-154B, using a strengthened floor, and adding a forward cargo door on the port side of the fuselage. The aircraft could carry nine Soviet PAV-3 pallets. Maximum payload – . There were plans for 20 aircraft, but only nine were converted, two from Tu-154 models and seven from Tu-154B models. Trials were held in the early 1980s and the aircraft was authorized regular operations in 1984. By 1997 all had been retired. ; Tu-154M : The Tu-154M and Tu-154M Lux are the most highly upgraded versions, which first flew in 1982 and entered mass production in 1984. It uses more fuel-efficient
Soloviev D-30KU-154 turbofans. Together with significant aerodynamic refinement, this led to much lower fuel consumption hence longer range, as well as lower operating costs. The aircraft has new double-slotted (instead of triple-slotted) flaps, with an extra 36-degree position (in addition to existing 15, 28 and 45-degree positions on older versions), which allows reduction of noise on approach. It also has a relocated
auxiliary power unit and numerous other improvements. Maximum takeoff weight increased first to , then to . Some aircraft are certified to . About 320 were manufactured. Mass production ended in 2006, though limited manufacturing continued as of January 2009. No new airframes have been built since the early 1990s, and production since then involved assembling aircraft from components on hand. Chinese
Tu-154MD electronic intelligence aircraft carry a large-size
synthetic-aperture radar (SAR) under their mainframe. ; Tu-154M-LK-1 : Cosmonaut trainer. The forward baggage compartment was converted into a camera bay, as the aircraft was used to train cosmonauts in observation and photographic techniques. Later converted into
open skies treaty observation aircraft. ; Tu-154M-ON monitoring aircraft : Germany modified one of the Tu-154s it inherited from the former
East German Air Force into an observation airplane. This aircraft was involved with the
Open Skies inspection flights. It was converted at the
Elbe Aircraft Plant (Elbe Flugzeugwerke) in
Dresden, and flew in 1996. After 24 monitoring missions, it was lost in
a mid-air collision in 1997. : The Russians also converted a Tu-154M to serve as an
Open Skies monitoring aircraft. They used the Tu-154M-LK-1, and converted it to a Tu-154M-ON. When not flying over North America, it is used to ferry cosmonauts. China is believed to have converted one Tu-154 to an
electronic countermeasures aircraft. ; Tu-154M-100 : Design of this variant started in 1994, but the first aircraft were not delivered until 1998. It is an upgraded version with Western avionics, including the
Flight Management Computer,
GPS,
EGPWS,
TCAS, and other modern systems. The airplane could carry up to 157 passengers. The cabin featured an automatic oxygen system and larger overhead bins. Three were produced, as payment of debts owed by Russia to
Slovakia. Three aircraft were delivered in 1998 to
Slovak Airlines, and sold back to Russia in 2003. ;
Tu-155 : A Tu-154 converted into a testbed for alternative fuels. It first flew in 1988 and was used until the fall of the Soviet Union, when it was placed in storage. == Proposed variants ==