British Airways (BA, London Heathrow (LHR)) and other fellow Oneworld alliance members who operate into Bangkok Suvarnabhumi International (BKK) have all denied claims by Airports of Thailand (AoT) that the group was keen to relocate their operations to Bangkok's old airport, Bangkok Don Mueang International (DMK), citing "flight connectivity constraints and service quality for premium passengers as key impediments." The Bangkok Post reports that newly appointed AoT chairman, Sqn Ldr Sita Divari, had on March 27 said that "Oneworld was interested in shifting to Don Mueang, even suggesting that the alliance had proposed the airport be upgraded to handle A380-800s." Despite opening as recently as 2006, Suvarnabhumi International has already exceeded its planned operating capacity of 50 million passengers per year by 5 million, forcing Thai authorities to push Don Mueang as an alternative in order to alleviate congestion. Don Mueang is currently mainly used by Nok Air (DD, Bangkok Don Mueang International (DMK)), Thai AirAsia (FD, Bangkok Don Mueang International (DMK)) and other low-cost and charter carriers.

Nok Air (DD, Bangkok Don Mueang International (DMK)) will launch daily service from Bangkok's Don Mueang airport to Ranong (UNN) from May 1. The service will initially be operated by Nok Air's partner Siam General Aviation (5E, Bangkok Suvarnabhumi International (BKK)) that operates regional services with Saab 340Bs under the Nok Mini brand. Nok then plans to upgrade the route to its own larger ATR72s from October 1. Ranong is located in Southern Thailand on the Northern Andaman Coast close to Thailand's border with Myanmar.

Nok Air (DD, Bangkok Don Mueang International (DMK)) has retired its last two B737-400s from scheduled service in March with B737-400 HS-DDL operating the last scheduled flights on March 19. The aircraft might still be used as a back-up aircraft for some time. Nok Air now operates ten B737-800s, one ATR72-500 and two ATR72-200s.

Nok Air (DD, Bangkok Don Mueang International (DMK)) CEO Patee Sarasin has told CAPA that Nok Air plans to launch a daily service from its home base at Bangkok's Don Mueang airport to Yangon Mingaladon International (RGN) using B737-800s in the third quarter of 2013 as its first international route. Nok Air also plans to serve Maulmyine (MNU) as the first international carrier, likely using Saab 340Bs of regional partner Siam General Aviation (5E, Bangkok Suvarnabhumi International (BKK)) as an extension of one of the five daily Saab 340B services between Don Mueang and Mae Sot.

Nok Air (DD, Bangkok Don Mueang International (DMK)) has added a first ex-Kingfisher Airlines (IT, Mumbai Chhatrapati Shivaji International (BOM)) ATR 72-500 HS-DRC (c/n 740) to its fleet. It had announced plans last year already to replace its fleet of two ATR 72-200s by newer used ATR 72-500s. Its regional partner Siam General Aviation (5E, Bangkok Suvarnabhumi International (BKK)) also operates five Saab 340As under the Nok Mini brand on domestic regional services in Thailand.