The Ivchenko Progress D-36 (also known as Lotarev D-36 ) is a three-shaft high bypass ratio turbofan currently produced by the Ukrainian Motor Sich company.
31-449: The engine was developed for the Yak-42 , An-72 and An-74 aircraft and was very advanced when it was first introduced in the 1970s. The engine was designed by Vladimir Lotarev . The first test runs began in 1971, first flight tests followed in 1974, serial production began in 1977. The engine has a single-stage fan with 29 titanium blades and a Kevlar outer shell, which is driven by
62-505: A Yak-42 for geophysical survey and environmental monitoring. Fitted with large underwing pods containing electro-optical sensors. Conversion as testbed for Progress D-236 propfan engine. Single D-236 (rated at 8,090 kW (10,850shp)) mounted in place of starboard engine, on special pylon to give sufficient clearance for 4.2 m (13 ft 9¾ in) propellers. First flew 15 March 1991. A projected but unbuilt stretched airliner. Planned to be powered by three Progress D-436 turbofans,
93-471: A design powered by three of the new Lotarev D-36 three-shaft high-bypass turbofans, which were to provide 63.90 kN (14,330 lbf) of thrust. Unlike the Yak-40, the new airliner would have swept wings. The first of three prototypes, which was fitted with an 11-degree wing and registered SSSR-1974 , made its maiden flight on 7 March 1975. It was followed by the second prototype, ( SSSR-1975 ) with
124-456: A failure of the actuator screw jack , causing the aircraft to fatally crash near Mazyr . The type was grounded as a result, not returning to service until October 1984. An export order for seven aircraft was announced in 1982 by Aviogenex of Yugoslavia , but the contract lapsed. The availability of the longer-range Yak-42D variant from 1991 onwards gave rise to a few more export sales, to Bosnia, China, Cuba, and Iran. As of 1 January 1995
155-503: A result, many airlines have removed this system to reduce aircraft weight. A unique airstair design was used for the aft doors of 737 Combi aircraft, which consisted of a clamshell door which dropped down to open much like a business aircraft, but then had stairs which were stored trifold in the curve of the door, which would unfold to the ground. This system was very cumbersome, was very susceptible to damage, and thus has been removed by many of its users. The most unusual airstair design
186-459: A simple device known as a Cooper vane that prevented the ventral airstair from being opened in flight. The rear airstair of a DC-9 has been used to allow for recreational skydiving operations. During the 2012 Boeing 727 crash experiment , a flight crew took off in the Boeing 727 that was to be crashed and flew it to a pre-selected desert site before safely parachuting from the airstair, as
217-421: A stretched fuselage and new wings. Design developed into Yak-242. Further developed Yak-42M, with two underwing Aviadvigatel PS-90 turbofans. Design evolved into Irkut MC-21 . As of July 2019, 22 Yak-42s remained in commercial airline service. Operators are Izhavia (8), KrasAvia (10) and Turukhan Airlines (4). As of 15 February 2018, eight fatal accidents and one non-fatal incident have occurred on
248-466: A three-stage turbine . The six-stage low pressure compressor with titanium blades is driven by a single-stage non-cooled low pressure turbine. The seven-stage high-pressure compressor with steel blades is driven by a steel bladed high-pressure turbine. Since the tradition in the Soviet era was to gradually and continuously improve engines in serviceability, engines went from Series 1 to 3A (depending on
279-470: A total of 104 seats. In its first year of operation Aeroflot's Yak-42s carried about 200,000 passengers, mainly on routes from Moscow, but also on international services from Leningrad to Helsinki and from Donetsk to Prague , with the type being planned to enter wider service throughout the Aeroflot fleet. On 28 June 1982, however, the tailplane detached from an Aeroflot Yak-42 in flight owing to
310-861: A total of 185 Yak-42 had been produced, including 105 Yak-42Ds. Original production version. Max. takeoff weight 54,000 kg (119,050 lb). Version with modified avionics for use on international use ( mezhdunarodnyye linii – international services). Entered service in July 1981 on the Leningrad- Helsinki route. Long-range version ( Dal'niy – long range) increased fuel. Replaced standard Yak-42 in production. Derivative of Yak-42D with updated, western AlliedSignal avionics , spoilers to allow faster descent and enlarged cabin door to accommodate jet bridge . Also designated Yak-42A , Yak-42-100 and Yak-42D-100 . Yak-42 used as testbed for radar for Yakovlev Yak-141 fighter. Conversion of
341-466: Is efficient and because the aircraft which use it sit low to the ground, the design can stay simple and not add complexity or weight, one of the biggest problems with airstair assemblies. The design has also been used with a single-length set of extension stairs on aircraft such as the cargo compartment of the widebody Ilyushin Il-86 (the primary entrance to the aircraft for passengers), Boeing VC-25 , and
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#1732783439009372-471: Is equipped with one. This was attempted on 24 November 1971 by an unknown hijacker, widely known as D. B. Cooper , who jumped from a Boeing 727 along with US$ 200,000 in ransom money. However, it is unknown if he survived the jump. Subsequently, a number of individuals carried out copycat hijackings against Boeing 727s and safely parachuted to the ground, although all were apprehended by the authorities. To prevent this, Boeing 727s were ordered to be fitted with
403-520: Is flown by a flight crew of two pilots sitting side by side in a flight deck forward of the cabin. Access is via two airstairs , one in the underside of the rear fuselage, like that of the Yak-40, and one forward of the cabin on the port side. Two holds are located under the cabin, carrying baggage, cargo and mail. All of the prototypes had main landing gear with two wheels each, with the first serial production aircraft, four main wheels were introduced. The wing layout underwent considerable revision during
434-540: Is on An-74TK-300 . Data from Élodie Roux, page 158 Related development Related lists Yakovlev Yak-42 The Yakovlev Yak-42 ( Russian : Яковлев Як-42 ; NATO reporting name : " Clobber ") is a 100/120-seat three-engined mid-range passenger jet developed in the mid 1970s to replace the technically obsolete Tupolev Tu-134 . It was the first airliner produced in the Soviet Union to be powered by modern high-bypass turbofan engines. In 1972,
465-519: Is the current STC holder, as listed on the FAA's Dynamic Regulatory System. Dow Aero acquired the STC’s for the Boeing 727, 737, 747,757, 767, and L-1011 from Airweld Incorporated. STC's have been previously issued to subsequent manufacturers including Kaiser Aerospace, WAPCO, and Advanced Aerospace. On-Board Folding Airstairs can be found in use on many U.S., Foreign Military, and Government Aircraft, including
496-667: The Yakovlev design bureau started work on a short- to medium-range airliner capable of carrying 100–120 passengers. It was intended to be a replacement for the Tupolev Tu-134 jet as well as the Ilyushin Il-18 , Antonov An-24 and An-26 turboprop airliners. While the new airliner was required to operate out of relatively small airfields while maintaining good economy, as many Soviet airports had been upgraded to accommodate more advanced aircraft, it did not have to have
527-526: The 23-degree wing and a cabin with 20 rows of windows instead of 17 in the first prototype, and a third prototype ( SSSR-1976 ) fitted with improved de-icing gear. The Yak-42 is a low-winged monoplane of all-metal construction, with a design lifespan of 30,000 one-hour flights. It has a pressurised fuselage of circular section, with the cabin designed to carry 120 passengers in six-abreast layout (or 100 passengers for local services with greater space allocated to carry-on luggage and coat stowage). The aircraft
558-479: The Boeing E4B as well as VIP aircraft around the world. The On-Board Folding Airstairs is a multi-section (3, 4, or 5 segment) airstair that can be installed at either the forward, center, or aft doors. When retracted/closed, the airstair sits on a track and is typically stowed in a closet either Forward, Aft, or Transverse. A rear, ventral, airstair can be used as a safe means of parachuting from an airliner that
589-517: The Yak-42 with a total of 570 casualties. Data from Brassey's World Aircraft & Systems Directory 1999/2000. General characteristics Performance Related development Aircraft of comparable role, configuration, and era Related lists [REDACTED] Media related to Yakovlev Yak-42 at Wikimedia Commons Airstair An airstair is a set of steps built into an aircraft so that passengers may board and alight
620-644: The aircraft to be boarded by VIPs at any time - with or without the cooperation of ground services. Ventral airstairs are featured on most tail-engined airliners, such as the Boeing 727 , the McDonnell Douglas DC-9 , MD-80 and MD-90 , the BAC 1-11 , and the Yakovlev Yak-40 / Yak-42 series, and are incorporated as ramps which lower from the fuselage. The Ilyushin Il-86 has three airstairs on
651-585: The aircraft. The stairs are often built into a clamshell-style door on the aircraft. Airstairs eliminate the need for passengers to use a mobile stairway or jetway to board or exit the aircraft, providing more independence from ground services . Some of the earliest aircraft to feature airstairs were the Martin 2-0-2 and Martin 4-0-4 . Some models of the Douglas DC-3 were also retrofitted with airstairs (see picture). As airport infrastructure has developed,
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#1732783439009682-678: The application). The Series 1 (used on Yak-42D) did not feature any reverse thrust system however, series 1A to 3A were fitted with bucket-type thrust reversers (used on An-72/An-74). The most recent upgrade (after the Soviet breakup) is Series 4A which has been in manufacture since 2002. Improvements included updated curved titanium blades and a built-in reverse thrust device. More advanced blade design along with proprietary wear-resistant and heat-protective coatings have resulted in improved specific fuel consumption (kg/h/kgf) dropping from 0.65 to 0.63. Specified service life has also improved exponentially to 40,000 hours. The current application for Series 4A
713-405: The belly lounges of three Lockheed L-1011s . Another widespread type of airstair is used for forward doors. The stair folds and stows under the floor of the door and is deployed from the fuselage immediately below the forward door. This type of airstair is found on many short-range aircraft such as Boeing 737s , DC-9s, and some Airbus A320 series aircraft. The mechanism is also quite heavy; as
744-541: The cargo hold, with steps inside the cabin to access these stairs. Some aircraft, like the Boeing 727 and McDonnell Douglas DC-9 , were designed to improve ground services, with passengers deplaning from the front as the aircraft is serviced from the rear, enabling quicker turnarounds. Airstairs are also used as a security measure, for example on aircraft carrying the President of the United States , allowing
775-416: The design process, with the first prototype being built with a wing sweep of 11 degrees and the second prototype with a sweep of 23 degrees. After evaluation, the greater sweep of the second prototype was chosen for production. Early aircraft had a clean wing leading edge with no control surfaces, and plain trailing edge flaps . This changed in later aircraft, which were fitted with leading edge slats , with
806-618: The need for airstairs has decreased, as jetways or mobile stairways are often available. Wide-body aircraft rarely employ airstairs, as the doors are significantly higher above the ground than narrow-body aircraft . One notable exception is the Lockheed L-1011 , the only wide-body aircraft to feature full-height airstairs. The only other wide-bodies with airstairs, the VC-25 and the Ilyushin Il-86 , have airstairs contained in
837-521: The port side. The most common type of airstair is found in most business aircraft, regional jets, and other small airliners, which is a stair built into the inside of the main passenger door, which is lowered to the outside. Aircraft such as the Fokker F-28 series and the VFW-Fokker 614 made this design popular. The stairs are actually part of the door rather than an attached stair. This design
868-466: The same ability to operate from grass strips as Yakovlev's smaller Yak-40 . The requirement resulted in the largest, heaviest and most powerful aircraft designed by Yakovlev. Initial design proposals included a straight-wing airliner powered by two Soloviev D-30 turbofans and resembling an enlarged Yak-40, but this was rejected as it was considered uncompetitive compared to Western airliners powered by high bypass ratio turbofans. Yakovlev settled on
899-424: The trailing edge flaps slotted. Two engines were mounted in pods on either side of the rear fuselage, with the third embedded inside the rear fuselage, fed with air via an " S-duct " air inlet. An auxiliary power unit (APU) is also fitted in the rear fuselage. No thrust reversers are fitted. The aircraft has a T-tail , with both the vertical fin and the horizontal surfaces swept. The first production aircraft
930-484: Was completed on 28 April 1978, with the first scheduled passenger flight, on the Aeroflot Moscow- Krasnodar route taking place on 22 December 1980. Production was at first slow, with only 10 flown by mid-1981. Initial aircraft were fitted for 120 seats in a three-plus-three arrangement. This was soon changed to a first class section with two-plus-two seating, and a main cabin with 96 seats, giving
961-475: Was found on the Lockheed L-1011, which was a full-height airstair that was stored in a cargo compartment and allowed access from the right aft passenger door to the ground. This design was ultimately so large and heavy, and it took up valuable cargo space, that it was rarely used. One version of on-board folding airstairs were designed by Winters Aircraft Engineering Company over 30 years ago. Dow Aero