Possible Clues:

• Tiredness after a flight
• Hire car for Spooner causing tiredness
• Plane to American city key to traveller's concern
• 27 across finds American city great for what travellers are always complaining about
• Travellers' complaint with alien creature left in car
• It gets you off schedule
• Problem after a trans-Atlantic flight
• World traveler's woe
• Malaise caused by air travel
• One cause of daytime fatigue