Tupolev Tu-334

Tupolev

Industry	Aerospace, Aviation
Founded	1922
Headquarters	Moscow , Russia
Products	Aircraft including Tupolev Tu-334
Parent	United Aircraft Corporation (since 2009)

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Tu-334 exhibited at the 2007 MAKS Airshow, Moscow

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Tu-334 performing at MAKS 2007

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Tu-334 at the 2007 MAKS Airshow, Moscow

The Tupolev Tu-334 (Russian: Туполев Ту-334) was a Russian initiative aimed at producing a short-to-medium range commercial airliner intended to succeed the aging fleets of Tupolev Tu-134 and Yak-42 aircraft globally. Its design incorporated a shortened fuselage derived from the Tupolev Tu-204 and a scaled-down wing from the same model. Contrasting with the Tu-204, the Tu-334 featured a T-tail configuration and engines mounted on the rear fuselage sides rather than beneath the wings. Following the consolidation of Russian aerospace manufacturers into the United Aircraft Corporation in 2009, continuation of the Tu-334 project was discontinued.

Development

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Interior view of the Tu-334 cabin.

The Tupolev Design Bureau unveiled the Tu-334 concept in early 1989 as a future airliner potentially equipped with propfan engines, targeting entry into service with Aeroflot by 1995. An interim turbofan-powered variant was planned to commence operations between 1991 and 1992. The propfan engine promised about a 20 percent fuel efficiency improvement over the best available Soviet turbofans, utilizing an as-yet unnamed geared powerplant developed by the Lotarev engine design bureau. This engine was projected to have a thrust specific fuel consumption (TSFC) of 13 g/(kN⋅s) (0.46 lb/(lbf⋅h)), translating into approximately 13 grams per kilometre (0.74 ounces per mile) fuel burn per passenger. The turbofan variant would be powered by Lotarev D-436T engines, delivering a TSFC of 18 g/(kN⋅s) (0.62 lb/(lbf⋅h)) and featuring a bypass ratio of 6.5, with fuel consumption estimated at 20 g/km (1.1 oz/mi) per passenger. Seating capacity for the propfan version ranged between 104 and 137 passengers, while the shorter turbofan model accommodated between 86 and 102 passengers.

Shortly after, Tupolev confirmed that the turbofan version would employ D-436 engines. Concurrently, discussions began with International Aero Engines (IAE) during the 1989 Paris Air Show concerning adoption of a derated 7,500 kilograms-force (17,000 lbf; 74 kN) variant of IAE's V2500 engine rated at 11,345 kgf (25,010 lbf; 111.26 kN) thrust. These negotiations extended through year-end, driven by doubts over whether Lotarev could meet Tupolev’s schedule or fuel efficiency targets, or possibly due to cancellation of the propfan variant. Additionally, concerns existed that Tupolev might not satisfy Aeroflot's urgent capacity requirements promptly enough, potentially allowing the Yakovlev Design Bureau to compete by producing the Yak-42M—a derivative of Yak-42—due to its faster availability despite official preference for the Tu-334.

Details about the propfan engine began emerging in mid-1990 but were often inconsistent. In April that year, while announcing a revised interim service entry date of 1993, Tupolev’s chief designer indicated that an ultrahigh bypass Lotarev (later Progress) propfan similar to the General Electric GE36 UDF would be used instead of their original propfan design. Meanwhile, the Soviet Central Institute of Aviation Motors (CIAM) reported expectations for a propfan-powered Tu-334 entering service between 1995 and 1997, likely employing a geared propfan rather than an ungeared one. Subsequent reports identified this engine as the Progress D-27, a 3.8 metres (12 ft) diameter, 11.2 tf (110 kN; 11.0 LTf; 12.3 STf) thrust powerplant with a TSFC of 0.44 lb/(lbf⋅h) (12 g/(kN⋅s)). The D-27 was also slated to power the newly announced Yakovlev Yak-46, another propfan airliner similar to Yak-42M but featuring two propfans instead of three turbofans mounted at the rear fuselage. Three weeks later, Tupolev disclosed that government officials were deciding between two derivatives from Progress for final selection in 1996: either the Progress D-227 propfan or the Progress D-527 "super contrafan," an ungeared ducted contra-rotating engine with an impressive bypass ratio of 18. A few days prior, the Soviet Union had publicly demonstrated a running propfan engine on an Ilyushin Il-76LL testbed equipped with one Progress D-236 engine at the ILA Berlin Air Show in Hannover, Germany—the first such display to Western audiences. Although no specific aircraft application was named at Hannover, an October 1990 article identified this geared engine as intended for use on the final Tu-334 variant competing against Yakovlev’s D-27-powered Yak-46 for Aeroflot’s replacement of its Tupolev Tu-134 fleet.

Development work on the Tu-334 started in earnest during the early 1990s but progressed slowly due to financial difficulties following the dissolution of the Soviet Union. A prototype was shown in 1995; however, it was largely a mock-up lacking most systems. The first operational flight occurred on 8 February 1999. Later that year, agreements were signed for MiG to contribute to production efforts. After some delays, Russian type certification was granted on 30 December 2003.

Persistent budget constraints continued to hamper development pace, causing repeated postponements in certification and serial production commencement. By December 2006, seven airlines had placed firm orders for the Tu-334—including Atlant-Soyuz Airlines—and letters of intent were received from another twenty-four carriers totaling approximately 297 aircraft. The estimated unit price for a business-class configuration hovered around $43–44 million.

Among potential buyers was Iran, where negotiations were underway through Iran Aviation Industries Organization (IAIO) to secure licenses for assembly by 2011 and full manufacturing by 2015 alongside production of the Tu-214. However, no concrete progress materialized before cancellation of the program.

As late as 2008, Tupolev stated that roughly one hundred airlines had expressed interest in ordering Tu-334s; on July 31 that year, Managing Director Sergei Ilyushenkov announced plans to initiate production by January 2009. This target date also passed without any indication of serial manufacturing.

In mid-2009, after nearly a decade since its maiden flight and only two units built and flown, evaluation during restructuring within Russia’s aerospace industry led to termination of further development on the Tu-334 project. Focus shifted instead toward advancing other programs such as the Sukhoi Superjet 100, Antonov An-148, and Irkut MC-21.

Variants

Tu-334-100

Standard model accommodating 72 passengers in a mixed-class setup (12 in first class and 60 in economy) or up to 102 passengers in a dense seating arrangement. Equipped with two 73.6 kN (16,500 lbf) Progress D-436T1 turbofan engines.

Tu-334-100C

Conceptual combi variant designed for both passenger and cargo transport based on the Tu-334-100.

Tu-334-100D

Intended extended-range and lengthened model featuring a fuselage extended by 54 cm (21 in) and wider wingspan (32.61 m (107 ft 0 in)). It is powered by two 80.4 kN (18,100 lbf) Progress D-436T2 engines.

Tu-334-120

Planned evolution of the Tu-334-100, driven by a pair of 88.9 kN (20,000 lb_f) Rolls-Royce BR715-55 engines.

Tu-334-120D

Variant based on the Tu-334-100D but fitted with two Rolls-Royce BR-715-55 powerplants.

Tu-334C

Manufactured version tailored for cargo operations.

Tu-336

Proposed model utilizing liquid natural gas as fuel, featuring cryogenic tanks installed above the passenger compartment.

Tu-354

Further lengthened variant, initially designated as Tu-334-200, stretched by 390 cm (150 in) compared to the Tu-334-100, capable of seating up to 126 passengers. This version utilizes either Progress D-436T2 or Rolls-Royce BR-715-55 engines and includes reinforced landing gear with four-wheel bogies.

External links

• Tu-334 aircraft series information at Tupolev's official website (archived link)

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