flightless

Short definition from Wiktionary

Adjective

1. 1
   Unable to fly: Describing kinds of birds that normally cannot fly, such as the penguin, ostrich, and emu.
2. 2
   Unable to fly: Describing an individual bird that normally would be able to fly but in this case cannot, such as an injured sparrow.
3. 3
   Unable to fly: Suddenly deprived of a scheduled (airline) flight by its cancellation.