"Het vliegtuig wordt aan de grond gehouden." The flight-[something] was on the ground held (beheld, is English missing a tense/case here)? Right?
The form “gehouden” is a participle. It needs a verb which is “wordt”. That is, “was held.” Or I think, more literally, “became held” but that would be horrible English. “The plane was grounded.” is accurate enough I think. I’m not a native speaker, and my Dutch ain’t much, but that is how I would translate it.
Yes, The aircraft was held on the ground.