Question: The WS-15, code name Emei, is a Chinese after burning turbofan engine, a stealth, twinjet, fifth-generation fighter aircraft developed by China's Chengdu Aerospace Corporation for what airforce?
Context: The WS-15 (), codename Emei, is a Chinese afterburning turbofan engine designed by the Shenyang Aeroengine Research Institute and manufactured by the Xi'an Aero-Engine Corporation, used to power China's Chengdu J-20 fighter, which would be able to achieve supercruise. The Chengdu Aircraft Industry Group or Chengdu Aerospace Corporation, a subsidiary of AVIC, is a Chinese aerospace conglomerate that designs and manufactures combat aircraft and is also a manufacturer of aircraft parts.  It was founded in 1958 (as Chengdu State Aircraft Factory No.132 Aircraft Plant) in Chengdu, Sichuan province, China to be an aircraft supplier for the Chinese military. The Chengdu J-20 () is a stealth, twinjet, fifth-generation fighter aircraft developed by China's Chengdu Aerospace Corporation for the People's Liberation Army Air Force (PLAAF).  The J-20 made its maiden flight on 11 January 2011, but the plane was officially revealed on China International Aviation & Aerospace Exhibition in 2016.  In March 2017, Chinese media claimed that the aircraft has entered initial operational capability phase with limited service within Air Force. The WS-13 (Chinese: 涡扇-13), codename Taishan, is a turbofan engine designed and manufactured by Guizhou Aircraft Industry Corporation to power the Pakistan-China jointly developed JF-17 Thunder light-weight multi-role fighter, and in the near future the Shenyang J-31 fifth generation stealth fighter currently under development. The Chengdu J-10 ([[Simplified Chinese characters|simplified Chinese]]: 歼-10; [[Traditional Chinese characters|traditional Chinese]]: 殲-10; [[NATO reporting name]] : Firebird) is a lightweight [[multirole combat aircraft|multirole]] [[fighter aircraft]] capable of all-weather operation, configured with a [[delta wing]] and [[Canard (aeronautics)|canard]] design, with [[fly-by-wire]] flight controls, and produced by the [[People's Republic of China]]'s [[Chengdu Aircraft Industry Group|Chengdu Aircraft Corporation (CAC)]] for the [[People's Liberation Army Air Force]] (PLAAF). The HAL Advanced Medium Combat Aircraft (AMCA) is an Indian programme of a fifth-generation fighter aircraft.  It is being developed by an aerospace industry team which consists of the Aeronautical Development Agency (ADA) as the design firm with manufacturing carried out by Hindustan Aeronautics Limited (HAL) as the primary contractor and main assembly firm.  It is a single-seat, twin-engine, stealth supermaneuverable all weather multirole fighter aircraft.  Unofficial design work on the AMCA started in 2008 with official work started in 2011 and completed in 2014.  In 2008, the Indian Navy joined the programme seeking a naval variant optimized for operation from aircraft carriers.  The first flight is scheduled to occur in 2019. The Sukhoi Su-57 (Russian: Сухой Су-57 ) is the designation intended for a stealth, single-seat, twin-engine jet multirole fighter aircraft designed for air superiority and attack operations.  The aircraft is the product of the PAK FA (Russian: ПАК ФА , Russian: Перспективный авиационный комплекс фронтовой авиации , "Perspektivny Aviatsionny Kompleks Frontovoy Aviatsii", literally "Prospective Airborne Complex of Frontline Aviation"), a fifth-generation fighter programme of the Russian Air Force.  Sukhoi's internal name for the aircraft is T-50.  The Su-57 will be the first aircraft in Russian military service to use stealth technology.  The fighter is planned to have supercruise, stealth, supermaneuverability and advanced avionics to overcome the prior generation fighter aircraft as well as ground and maritime defences. The AL-41F is a designation for two different Russian military turbofan engine variants.  The NPO Saturn AL-41F is a Russian variable-bypass ratio turbofan engine, designed for supercruise flight for the "MFI" ("Mnogofunktsionalni Frontovoy Istrebitel", "Multifunctional Frontline Fighter") program, which resulted in the Mikoyan Project 1.44.  It is considered by Jane's as the Russian counterpart to the General Electric YF120 engine which lost to the more conventional fixed-bypass YF-119 in the Advanced Tactical Fighter engine program.  Since the cancellation of the MFI program, the AL-41F1S and AL-41F1 designation was assigned to heavily upgraded AL-31F variants that powers the Su-35S and initial production Sukhoi Su-57 stealth aircraft. Chengdu Aircraft Design Institute or 611 Design Institute (Chinese: 成都飞机设计研究所; pinyin: "Chéngdū fēijī shèjì yánjiūsuǒ"), or CADI, is a design institute and works with Chengdu Aerospace Corporation for military aircraft. J-XX J-X, and XXJ are names applied by Western intelligence agencies to describe programs by the People's Republic of China to develop one or more fifth-generation fighter aircraft.  General He Weirong, Commander of the People's Liberation Air Force (PLAAF), stated that China had several such programs underway and that an undesignated fifth-generation fighter developed jointly by Chengdu Aerospace Corporation and Shenyang Aerospace Corporation would be in service by 2018.
Answer: People's Liberation Army Air Force