The aircraft, primarily constructed with aluminium alloys, is powered by CFM International LEAP turbofan engines and carries 156 to 168 passengers in a normal operating configuration up to 5,555 km (3000 nmi; 3,500 mi).

In 2023, COMAC announced that it would develop both a shortened and a stretched version of the passenger jet – similar to the sub-variants offered for the competing Boeing 737 MAX and Airbus A320neo family.

[14] Canada's Bombardier Aerospace started collaborating in March 2012 on supply chain services, electrical systems, human interface, cockpit, flight training, flight-test support, sales, and marketing.

[16] The first prototype was expected to complete final assembly in 2014 and perform its first flight in 2015;[17] however, delivery was delayed again until 2018 due to technical difficulties and supply issues.

[23] On 12 July, the static test aircraft simulated a 2.5g manoeuvre with a 150% ultimate load, bending the wings at the tips by nearly three metres for three seconds.

[24] According to a report from cybersecurity firm Crowdstrike and a US Justice Department indictment, from 2010 to 2015 the Chinese cyberthreat actor Turbine Panda, linked to the Ministry of State Security's Jiangsu Bureau, penetrated a number of the C919's foreign components manufacturers including Ametek, Capstone Turbine, GE Aviation, Honeywell, Safran, and others and stole intellectual property and industrial process data with the aim of transitioning component manufacturing to Chinese companies.

[28] In November 2022, a federal jury in Cincinnati convicted Yanjun Xu, 42, on counts of conspiracy to commit economic espionage, conspiracy to commit trade secret theft, attempted economic espionage and attempted trade secret theft.

The US court found that Xu played a key role in a plot to steal trade secrets from western aerospace firms, for the purpose of helping the C919 commercial airliner program.

[35] Comac had its second prototype ready on 28 July 2017, aiming to fly it within the year for engine, APU, fuel system and extreme weather tests.

[citation needed] The delay between first and subsequent flights underlined the program immaturity by maiden flight: flying early at low speed and altitude is possible but faster and higher is limited by aeroelastic flutter needing ground vibration testing and aircraft instrumentation which were not ready in May.

[43] In June 2018, Aviation Week reported flight-test aircraft grounding for modifications, extending the schedule by three months but maintaining a 2020 certification target.

The two prototypes needed their flaps and tailplanes modified, due to delamination of the carbon-fiber reinforced plastic elevators.

The third was in final assembly with its wing and fuselage joined, cables and systems were being installed for a first flight target by the end of the year.

[47] In October 2018, the flight-deck design was re-evaluated to comply with US FAR Part 25.1302, which is not required by CAAC but would be needed for FAA certification in order to sell the aircraft outside China.

To achieve certification in December 2020 and first delivery in 2021, the planned 4,200 h of flight tests would need 33 hours a month each if the last four prototypes are evenly spaced before year-end-2019.

Newest airliner designs like the Airbus A350 needed a 2,600 hour test program, and the Mitsubishi MRJ was expected to need 3,000 h.[49] On 15 October 2018, ten Chinese nationals, including intelligence officials, were indicted by the US for allegedly working with COMAC to allegedly steal the secrets of thirteen foreign aerospace companies working on the C919.

[56] On 27 November 2020, the C919 received its type inspection authorization from the CAAC, meaning that "the aircraft design has been finalised and verified, and that no major changes can be made to its structure.

Around the same time, the first production aircraft, bound for China Eastern Airlines, started performing flight tests to ensure its preparation for commercial service.

[citation needed] In February 2023, China Eastern Airlines' C919 flight-test verification program was delayed due to a malfunction in the jet's CFM International LEAP-1C engine's thrust reverser.

[citation needed] On 7 May 2023, test flights resumed after a three-month break that had grounded the entire fleet of C919s; the airline continued to plan for passenger revenue-service to commence in spring 2023.

[66][67] China Eastern Airlines inducted a second C919 aircraft, registered as B-919C, with a formal reception taking place on 14 July 2023 at the flight test complex building of Zhuqiao base.

A C919 operated by China Eastern Airlines was chartered to fly a group of students from Hong Kong to Shanghai for an exchange program.

[79][80] In September 2023, COMAC Chairman He Dongfeng revealed, however, that shortened and extended variants of the C919 would also be built, covering a range from 130 to 240 seats.

[81] On 17 December 2023, COMAC signed a deal with Tibet Airlines to jointly develop the high-altitude version of the jet in order to serve passengers in the Tibetan-Himalayan plateau.

[82] The shortened version of the C919 is anticipated to serve routes with high-altitude landing sites, with a typical seating range of 140 to 160 passengers.

[47] While the airframe is entirely made by AVIC, some systems are sourced from a wide variety of international suppliers, similar to Airbus and Boeing.

[93] It has been reported that COMAC is working on a plan to become more self-sufficient in terms of suppliers, with a long-term goal of replacing all US-export controlled components, due to American export restrictions affecting their ability to boost jet output.

[107] They both provide a wide range of different configuration choices for the customer, for example adjustable headrest, mobile device holder or USB socket.

[117] In 2013, Chinese state-owned newspaper Global Times complained that an Aviation Week editorial about the bleak prospects for the aircraft "maliciously disparaged the future outlook for the C919".

[147] In a stock exchange filing on 26 April 2024, Air China said that it had ordered 100 C919 aircraft, which would be delivered between 2024 and 2031, thereby adding another high-profile customer for the narrowbody programme.