And with airlines under continual pressure to pack flights with paying passengers, that free ticket will only become more elusive as travel demand rebounds.
While the darts made mostly of tungsten steel can last a decade, the shafts and the feathered backs, called flights, need continual repair at a minimal cost of about $10 a year.
Watching Celtic, even in Scotland's top flight, leaves the continual impression of a team lacking a vital, exciting ingredient.
This would allow the airline to connect the route to the Hong Kong-flights, giving one continual service.
Once this new engine is certified, we can expect continual, radical improvements to small aircraft flight.
Because of the damage in the tail, the plane had a continual tendency to turn right, and without flight controls it was difficult to maintain a stable course.
Larger particles that are the size of fine sand, 0.05 mm (0.002 inch) to 0.5 mm (0.02 inch) in diameter, can be vaulted as high as 25 cm (10 inches) into the air, then drop to the ground after a short flight, only to rebound under the continual driving force of the wind.
Continue to seek out a continual future.
Trimming the aircraft is a continual process, with adjustments necessary for changes to the flight or power controls that result in changes in speed or attitude.
