TWENTY-ONE China Eastern Airlines flights returned to their departure point just after taking off from Yunnan on March 31 and April 1, disrupting the travel plans of more than 1,000 passengers.
The Shanghai-based carrier at first blamed poor weather, but passengers became suspicious after learning that other carriers had operated normally in Yunnan on that day.
Media reports suggested the pilots were protesting over pay and working conditions.
China Eastern and the Civil Aviation Administration of China sent a team to the southwestern province to investigate.
On Monday, the carrier announced that it had suspended two senior officials in its Yunnan subsidiary from duty after some crew members had been found intentionally disrupting flights.
"There are some flights that, rather than returning for weather-related reasons as the crew indicated at the time, clearly had a human element involved," the carrier said in a statement.
The aviation watchdog said that the weather in Yunnan was suitable for flying on March 31.
The carrier has suspended some suspects, and Li Yangmin, vice general manager of China Eastern, will now work as acting general manager of the Yunnan arm.
The company apologized to passengers and pledged to severely punish those responsible and compensate passengers.
It acknowledged management weaknesses and vowed to make improvements and safeguard passengers' benefits.
China Eastern officials also said that it would be compensating passengers with payments of up to 400 yuan (US$57).