24th March 2022Xian Y-20 user+1@localho Thu, 03/24/2022 - 21:17
The Xian Y-20 Kunpeng is a four-engine transport aircraft designed to bolster the People s Liberation Army Air Force (PLAAF) s strategic airlift capability. While China matures its own WS-20 engine for the project, early production Y-20s are powered by Russian UEC Saturn D-30KP-2 turbofan engines supplying 26,455 lbf. (117.7 kN) of thrust each at takeoff. The Y-20 is similar in configuration and role to the Boeing C-17 Globemaster III.
In 2003, China s State Council authorized the establishment of a study group for a new transport aircraft. It issued a plan in February 2006 for 16 major projects from 2006 to 2020, one of which would be a heavy transport aircraft for China s military. The program was officially authorized on Feb. 26th, 2007.
China had since 2005 attempted to procure 34 Ilyushin Il-76s and four Il-78 aerial refuelers from Russia, but disputes over pricing between Russia and the (independent) plant in Tashkent, Uzbekistan producing the aircraft killed the acquisition while Russia relocated the production line. Because of labor issues and the contract dispute, the plant would not guarantee delivery of any more than 16 aircraft (the number of airframes it already had on hand).
In the background, China approached Ukraine s Antonov to negotiate cooperation on developing an all-new airlifter. Antonov had since 2000 already worked with China s AVIC to upgrade the PLAAF s fleet of An-12s, Y-8s and An-2s and to design the wing of the ARJ 21. By mid-2006 Ukraine had offered China the An-70, a four-engine airlifter with a supercritical wing developed in the dying days of the Soviet Union that first flew in 1994.
Unfortunately, the An-70s 103,600 lb. (47,000 kg) payload capacity and 730 nmi. (1,350 km) range at maximum payload were considered insufficient for Chinese requirements. China also had no interest in the temperamental D-27 turbofan engine envisioned for the program. Instead, it proposed to design a new aircraft around the D-30KP-2. The new transport would require a range equal to or better than that of the Il-76TD.
Antonov responded by suggesting a derivation of the An-77, a variant of the An-70 with a dramatically increased maximum take-off weight (MTOW) of 412,300 lb. (187,000 kg) and a 2 m (6.56 ft) fuselage plug forward of the wings to increase cargo volume. The An-77 concept originally called for CFM56-5A16 engines, but as proposed to China it would use the D-30KP-2. The proposal was designated Y-XX and included as objectives a 440,900 lb. (200,000 kg) MTOW and a 110,200 lb. (50,000 kg) payload.
The design changed again, and the proposal was further enlarged in line with the An-170 proposal for an aircraft with a 507,000 lb. (230,000 kg) MTOW, 132,300 lb. (60,000 kg) payload and a standard wing profile. The requirements creep was largely driven by the desire to ensure the Y-XX could carry China s most modern (and heaviest) tank, the Type 99-IIA, also known as the Type 99A2, ZTZ-99-IIA or ZTZ-99A2. The Type 99 weighs at most 127,900 lb. (58,000 kg) in its combat ready configuration. Discounting fuel and ammunition this equates to roughly 121,250 lb. (55,000 kg).By July 2009 work was underway at the 606 Institute on the WS-20, and by August of that year work was underway on the rear fuselage of the first prototype Y-XX. By the end of the year the aircraft was known as the Y-20. In January 2012, the airframe for the first prototype was structurally complete. The C-17 may have directly influenced the design during this period through Su Bin, a Chinese national working in the aerospace industry in Canada who helped two PLA hackers steal 630,000 documents pertaining to the C-17 from Boeing between 2008 and 2014. Bin was arrested in Canada in July 2014, extradited to the U.S., and sentenced to 46-months in federal prison after pleading guilty to conspiring to gain unauthorized access to a protected computer and to violate the Arms Export Control Act.
In January 2013 a Y-20 was observed on commercial satellite imagery at a runway at the PLAAF s Yanliang airfield, surrounded by personnel and ground equipment. Yanliang airfield is associated with the China Flight Test Establishment (CFTE), and the aircraft was likely undergoing taxi tests in preparation for its first flight, which took place on Jan. 26, 2013.
The Y-20 features a high-mounted swept wing with a supercritical airfoil. It is anhedrally mounted to counteract the excessive roll stability associated with a high wing design. The aircraft has a large, swept T-tail; leading edge slats; large triple slotted flaps; and conventional ailerons, elevators and rudder. Large spoilers are mounted to the wing.
It has tricycle landing gear, with two wheels for the nose gear and twelve wheels for the main gear (in two arrays of three pairs).
The Y-20 features a pressurized cargo cabin and a rear ramp. Passengers typically enter through a door on the port side of the aircraft near the nose. paratroops doors aft of the wheel wells, though the Y-20 also supports static line jumps over the open cargo ramp. The Y-20 has also been photographed airdropping the ZBD-03 airborne infantry fighting vehicle.
The cargo bay is about 12.75 ft. (3.9 m) wide and about 12 ft. (3.7 m) tall, though the usable volume of the bay is slightly less than this suggests due to the rounding of the fuselage. Excluding the ramp, the bay is about 50.9 ft. (15.5 m) long, or 63.9 ft. (19.5 m) with the ramp included.