Flag carrier Thai Airways is suing a passenger who criticised the diversion of a Bangkok-Melbourne flight to Sydney due to poor weather.

The state-owned airline - which has become notorious for its corruption and mismanagement in recent years - said on on February 1 that it will be starting proceedings against businessman Ekapak Nirapathpongporn, 40, over his criticisms that 'created incorrect understanding in the public'.

In a lengthy online post accompanied with screenshots of a phone weather app, Ekapak had earlier slammed the pilot of Flight TG 465 flying from Bangkok to Melbourne on January 28.

He claimed the pilot was incompetent, unable to speak English confidently, and had lied to them about poor visibility that led to the plane's diversion to Sydney.

However, his tirade backfired when Captain Faisal, another pilot at Thai Airways, responded to his grievances one by one.

Faisal said: 'When you arrived in Melbourne, the weather was adverse, with a visibility of 200 meters and thick fog. Even if you were driving you could hardly see the road. Around the same time, there were many planes that were also diverted.

'Aviation weather reports are different from the ones you can get on phone apps. It is specialized news. Try looking at an airport app, and it would tell you clearly what the weather is like in a specific location.'

He added that all pilots must pass an aviation English test administered by a central institute.

Ekapak has since deleted his post. In a public apology before going private on Facebook, he said: 'My post, which was personal and emotional, intended to convey that the communication with passengers was not enough for me in that incident. Still, my message appeared inappropriate, and I apologize here to all those affected.'

Thai Airways said in a statement: 'Regarding the case of someone posting information about our flight operations and personnel on flight TG 465 on January 28, 2024, route Bangkok - Melbourne, it was necessary for the plane land an alternative airport for weather reasons.

'However, the online content has caused damage and affected the public reputation of the company.

'The company has safety standards regarding aviation and the safety of its personnel.

'At this time, we are currently undergoing legal procedures to protect the legitimate rights of the company and personnel who were affected in this case. This is to ensure such an incident will not create incorrect understanding for the public again in the future.'

In August 2020, a scathing investigation panel launched by the country's Ministry of Transport into Thai Air found mismanagement linked to dozens of executives and corruption had caused chronic financial losses and ultimately its bankruptcy rehabilitation.

The minister claimed to have evidence of bribes worth hundreds of millions of dollars paid to politicians, officials and airline executives in connection with the purchases of new planes, according to local newspaper, the Bangkok Post.

There has also allegedly been a culture of endemic fraud throughout the airline, with staff inflating overtime for imaginary work.

The airline has been undergoing court-supervised business rehabilitation since filing for protection in September 2020.