It was loved for its convenience to the city and its numerous daily flights, and hated for its congestion, short runways and stomach-jolting tight turns to avoid restricted airspace.

Avoiding Panamanian airspace added 250 miles to his trip.

They diverted him to the south by recommending a descent to 18,000 feet into winds blowing southward toward the border of Algeria and Niger, avoiding Libyan airspace.

Some countries establish low-altitude VFR corridors for non-towered airports in large urban areas so that VFR arrivals and departures can avoid controlled airspace altogether.

Avoiding busy airspace and looking for easy landmarks below, he flew west across the Shenandoah Valley into West Virginia and into Kentucky, where he picked up fuel at a four-thousand-foot strip not far from Lexington.

He was also betting that the Japanese would avoid Chinese airspace and come in from the east, the most direct route from Khabarovsk after avoiding China.

The aircraft avoided Cuban airspace, but came close enough to pass its flight control over the Marine air traffic crew at Guantanamo.

Although winds are expected to carry the balloon across North Africa, the team meteorologist said the track would avoid Iraqi airspace by at least 50 miles.

The beam must avoid airspace around airports and busy air routes.

The pilot will choose a route, taking care to avoid controlled airspace that is not permitted for the flight, restricted areas, danger areas and so on.