Possible Clues:

• Right, plane -- don't bust out of this!
• Restrain doctor attending flier -- that may be required by air traffic control
• Aircraft slower
• Right to end plan, changing course before landing
• Thing plane 'trod' when circling round?
• Flight before landing may have to go round this
• State of inaction
• Keeping model aeroplanes, stacks of them
• Had long trip - ten circuits here?
• 'What's that knitter doing during air turbulence?'