A Thai Airways Airbus A340-600, registration HS-TNB performing flight TG-916 from Bangkok (Thailand) to London Heathrow,EN (UK) with 266 passengers, was climbing out of Bangkok's runway 01R when the crew stopped the climb at FL130 due to a hydraulic problem, entered a hold to dump fuel and returned to Bangkok for a safe landing on runway 01R about 80 minutes after departure.

A replacement Airbus A340-600 registration HS-TNE is estimated to reach London with a delay of 160 minutes.
http://www.aeroinside.com/item/5132/...raulic-failure