Behind the Scenes with an Unsung Hero Engineer and the Story of ARJ21’s First Flight

August 31, 2015 | Author: Cash Liu (Lei Liu)

Oct. 12, 2014, a normal Sunday. 


Holding the testing devices, I was with Zhang Mingfeng in front of the ARJ21 Iron Bird laboratory building at the Shanghai Aircraft Design and Research Institute (SADRI) waiting for the authorized shuttle bus to transport us. The shuttle would send Zhang’s team and me to the Dachang Airbase affiliated with the Naval Air Force. Space is rented there by the Commercial Aircraft Corp. of China (COMAC) to operate flight tests an experiments. 

Zhang joined COMAC affiliate SADRI as the technical officer in charge of the ARJ21 primary flight control system (PFCS) manufactured by Honeywell.  I rushed to the test site as soon as I received Zhang’s call at 4 p.m. asking for help. AC106, the sixth ARJ21 plane assembled, was about to start its first flight. However, one of the ground tests was experiencing interruptions. SADRI needed Honeywell’s ARJ21 team to provide technical support and onsite troubleshooting as soon as possible.

I have known Zhang for years. He is low-key, professional and calm. Our friendship began in the winter of 2009, when the outdoor temperature at the Xi’an flight test site dropped to around -5°C. We stayed at the hangar troubleshooting without heat for nine consecutive days. Around midnight of the fifth day, when I could barely talk because my lips were trembling so much with cold, Zhang brought me a military coat for warmth. Since then, he became my “friend in need” and we built an unbreakable friendship. When he called, I could tell from his voice the problem was urgent and required an immediate solution. 

Ma Xianchao, Zhang’s direct supervisor as well as Minister of SADRI avionics and flight control systems, and Zhao Yanli, Manager of Supplier Management for Shanghai Aircraft Manufacturing (SAMC) where the ARJ21 is manufactured and assembled, called me in immediately after Zhang. To enhance the onsite organization and coordination, Minister Ma said he would participate in the evening testing personally. Zhao told me all the preparation work was done and the detailed test review already had been sent to me. The troubleshooting was scheduled at 21:30 and I was expected to arrive and stand-by at 20:00.

Pan Zhihao and Wang Rujun from maintenance were assigned to assist me. Wang and I had been working together over several years and had generated a tacit cooperation. In 2010, the outdoor temperature at the Xi’an Yanliang site was close to -10°C.I didn’t sleep for 74 hours to resolve a malfunctioning onboard ground connection that caused flight control software loading failure. The setting was a hangar built entirely of iron boards without heating or air conditioning. Every morning when I opened the hangar gate, it was Wang and Qing Li who brought me a cup of hot coffee and saved me from freezing.

Since joining the ARJ21 team, I’ve become familiar with various scenarios. So after I hung up the phone, I went through all the possible malfunctions in my head. But what was different from Xi’an Yanliang site was that Shanghai Dachang had sufficient spare parts. In addition, SAMC took all the transportation and works under control because the site was located at the apron of Dachang Airbase. We would just need to wait for the SAMC maintenance team to accompany us into the site.


All the technicians were in place and the troubleshooting began. The onsite work status was well explained by the photo published in the COMAC booklet.  Yes, every leader onsite was focusing on you; your judgment and decision would directly impact the status of the aircraft and the following flight test plan. 

Troubleshooting allowed us to infer and confirm problems through the observable malfunctions, and thus fix them. For an aircraft-system-level test, input sources were extremely complicated and quick examinations were dependent on technical guidance and experiences. Based on the problems and test projects the team was facing today, it would require 2.5 hours to complete a set of regular tests. Pulling another all-nighter was inevitable. 


We isolated and located the malfunction source through just one set of examinations, thanks to the assistance of SADRI and the maintenance team. Both SADRI and SAMC were very satisfied with the results. I looked at the newly painted AC106 with all sorts of feelings well up in my mind when the maintenance workers were on the way to storage to pick up the spare parts. After five years of hard work, finally the plane was about to get certified to come into service. As an engineer, it was such a proud moment to realize I was contributing my efforts to ensure that each future passenger flying with ARJ21 could safely enjoy the best flight performance. 

Because of safety policies, although I flew with ARJ21 passing Xi’an, Urumchi Xinjiang and Zhuhai, I barely took any photos with the plane. The next day, I received a photo taken by a maintenance guy, which captured my sentiments perfectly – my shadow was reflected on the elegant body of ARJ21, with all my best wishes and blessings. 


The new component was assembled properly.


The new aircraft passed the ground test on the first shot. Zhang was very excited and reminded me that “it was always us two who conducted the final examination and verification overnight, same with AC103, AC104 and today with AC106.” Of course, I remembered clearly: I had just gotten married then, and my wife was curious about the kind of work that required me to rush to the site at 2 a.m. Zhang laughed when I told him this story. 


Ground test re-check was passed on the first shot. On the way back, I sent Zhao and Wesley Yi, the project manager based in the U.S., an email, “the malfunction is cleared, PFCS is ready for the first flight.” 

When the technical team was leaving the site, Mr. Ma said to me, “I wish today would be the last time you had to support the flight test overnight.” At the time, I couldn’t think of that night as the last time I gave support to an ARJ21 flight test. 

13 days later, Oct. 27, 2014, AC106 completed its first flight successfully. 

78 days later, Dec. 30, 2014, ARJ21, an advanced regional jet with comprehensive proprietary intellectual property rights, received certification after 12 years of development and examination and 5,258 safe flying hours. 

Once I thought about how I should conclude the experiences and takeaways from this project and this team. However, when I received the certificate of honor from the COMAC onsite experiment team, I realized this was the best award and the best summary. “Dear Mr. Lei Liu, you have participated in the ARJ21-700 advanced regional jet experiment, first flight and certification process. We would like to extend our sincerest gratitude and highest respect for your dedication and all your hard work. This commemorates your achievement. ”

It was worth everything. 

About the ARJ21 Regional Jet

ARJ21, short for Advanced Regional Jet for the 21st Century, is a new type of turbofan short-/medium-range regional jet. It is designed and manufactured in China with independent intellectual property rights. COMAC selected Honeywell’s fly-by-wire flight control system for the ARJ21. It enables an electronic interface between the cockpit and the aircraft flight control surfaces, ensuring smooth and safe aircraft handling for the pilot. Honeywell’s system is used on many commercial aircraft. In addition to the ARJ21, Boeing 787 and the Embraer 170/190 family, it was selected for COMAC’s new C919 single-aisle commercial airliner.

The standard ARJ21’s range is 2,225 kilometers, which meets operation requirements of hub-spoke routes. Maximum takeoff weight of the aircraft is 40,500 kilograms, with a maximum operating altitude of 11,900 meters and a maximum range of 3,700 kilometers. Two CF34-10A engines are mounted on the rear of the aircraft. The aircraft’s dual-class configuration seats 78, with economy class configuration seating 90. The aircraft’s economic life is designed for 60,000 flying hours/20 calendar years.

Cash Liu

Cash Liu (Lei Liu)

Cash Liu (Lei Liu) is a Honeywell Aerospace Sr. Systems Engineer and Project Manager for Honeywell Technology Solutions Center in China. He earned a master’s degree in mechanical design manufacturing and automation from Tongji University in Shanghai. He has participated in many key projects, including COMAC’s C919 and ARJ21 aircraft. He also was responsible for China’s first launch of Honeywell’s Ground-Based Augmentation System (GBAS) at Pudong International Airport. Liu holds a private pilot’s license issued by the Civil Aviation Administration of China (CAAC).

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