By Bloomberg News on June 13, 2012

Prices for Boeing (BA) (BA) Co. 747-400s, the most popular wide-body plane, are tumbling as carriers rush to replace what were once their flagship aircraft with newer and more fuel-efficient models.

Thai Airways International Pcl. is in the process of selling four 747-400s and

it will begin phasing out the model next year, outgoing-Chief Executive

Officer Piyasvasti Amranand said May 31 in Bangkok.

Read more: Fuel costs end 23-year reign of Boeing 747-400

British Airways confirmed the emergency landing made of an A321 last month after the pilots complained of feeling lightheaded and put on their own oxygen masks before the plane touched down. The flight bound for Glasgow, Scotland,

Read more: British Airways pilot made emergency landing after feeling ‘ light headed’