A China Southern Airlines Airbus A321-200, registration B-6343 performing flight CZ-6763 from Shenzhen to Luoyang (China), was climbing out of Shenzhen when the crew stopped the climb at 6000 meters (FL197) and began to squawk loss of communication. The aircraft returned to Shenzhen for a safe landing about 35 minutes later.

The airline reported the crew dealt with a short term communication failure and decided to return to Shenzhen as a precaution.

A replacement A321-200 registration B-6379 reached Luoyang with a delay of 2:45 hours.