Possible Clues:

• No-brain
• Help to ring bird, coot?
• Stupid person needing help to catch flightless bird
• -
• During bungled raid, explosive placed next to a military base
• Dope in military base behind enemy lines
• Hardly a brainiac
• The pilot, maybe he's scatterbrained for first class heard a different order
• Excellent teacher restraining troublemaker finally, vacant sort
• Husband's absorbed by first rate book — The Idiot?