An adjustable oropharyngeal airway apparatus includes a rigid airway portion comprising a mouthpiece and a flexible airway portion frictionally engaging and slidably disposed in the mouthpiece. A data link is configured to allow the aircraft to communicate data with at least one other aircraft in the formation flight of the plurality of aircraft. The invention also extends to the transformed plants, plant parts, and seeds and progeny thereof. The polishing liquid supply port is configured to selectively discharge polishing liquid during the conditioning operation.