China’s C919 passenger plane, developed to compete with the best from Boeing and Airbus, used to be ridiculed for its dependence upon foreign parts and technologies. However, lately it is becoming known for the development and inclusion of key components developed and manufactured in China.

Now the Commercial Aircraft Corp of China (Comac) is about to scrap plans to use imported landing gear equipment and instead procure the vital components from state-owned Aviation Industry Corporation of China.

Nose landing gear and main landing gear made by an AVIC subsidiary in the central Hunan province have undergone rigid tests ahead of delivery.

The C919’s landing gear under the wings at mid-cabin rotates into wells in the aircraft’s belly just like that on the Boeing 737s. The legs are covered by partial doors, and brush-like seals aerodynamically smooth the enclosure when the landing gear is retracted, and the wheels in the wells.

Yet it is not clear if the sides of the tires of the C919’s tricycle undercarriage will be exposed to the air in flight like the 737’s land gear.

800px-737under
A Boeing 737-700 with main undercarriage retracted in wheel wells without landing gear doors. Photo: Filip.vidinovski/WikiMedia

Multiple redundancies are provided to prevent a single glitch from failing the entire landing gear extension process. Reports say that the C919’s landing gear can be operated both electrically and hydraulically.

The physical rigidity of tires as well as that of the wheels when the aircraft accelerates to high speed during take-offs and their ability to withstand huge impacts during touchdown are key to ensuring the safety of an aircraft and its passengers.

AVIC said it will also bid for the contract to supply landing gear for the CR929 wide-body planes, currently under joint development by Chinese and Russian SOEs.

The C919 is a single-aisle, narrow body jet for short- to medium-haul flights designed chiefly for the use of Chinese airlines to reduce their costly reliance on 737s and 320s from Boeing and Airbus. The Chinese plane is now on track to obtain its certificate of air worthiness as early as 2020, with multiple prototypes currently undergoing flight tests.