China's C919 passenger airplane will enter into a new phase of intensive test flights in the second half of this year, according to the Commercial Aircraft Corp. of China (COMAC). 

A total of six prototypes of the jetliner model will be put to the intensive test flight missions with two more aircraft set to join the fleet, said the developer. 

On August 1, the fourth C919 prototype completed its first test flight mission. It took to the sky over Shanghai Pudong International Airport and underwent various inspections and system checks during the flight of one hour and 25 minutes. 

The fourth C919 prototype mainly underwent tests covering the avionics system, taking-off and landing performances, automatic flight system and performances in natural icing conditions. 

These flight tests are a key verification phase for an aircraft model to validate its design and performance, especially its safety aspects. 

The C919, China's first homegrown trunk jetliner, conducted a successful maiden flight on May 5, 2017, at Shanghai Pudong International Airport. 

To date, the COMAC has received 815 orders for the C919 planes from 28 customers worldwide. 

The C919 airplanes will fly to various airports to undergo rigorous testing in complex weather conditions and a series of high-risk test flights, according to COMAC. 

COMAC will facilitate the test flight activities of the C919 project in multiple bases around the country, covering Yanliang, Dongying, Nanchang and Shanghai.