Ond mae Gweinidogion y Du wedi dweud y byddai'n rhoi mantais annheg i Gaerdydd dros feysydd awyr rhanbarthol eraill y DU. Mae'r pryderon hyn wedi cael eu chwalu gan ymchwil annibynnol.
But UK ministers have said it would give Cardiff an unfair advantage over other regional UK airports. These concerns have been debunked by independent research.