Final answer:
The amount of flight fuel for a flight is based on the airplane's size, speed, and air resistance, relatively independent of passenger load.
Step-by-step explanation:
The amount of flight fuel provided on each flight is primarily based on factors like air resistance, size, and speed of the airplane, and it tends to be relatively consistent regardless of passenger load.
This is because most of the energy in flight is used to overcome air resistance, which doesn't significantly change with the number of passengers. Furthermore, the fuel requirements for aircraft also take into consideration the specific distance to be traveled, as well as the weight of the aircraft itself, including passengers and cargo.
For instance, if three people were traveling from San Diego to San Francisco, a distance of 700 km, to use less fuel on a per-person basis than a plane that is 80% full and offers 90 miles per gallon per passenger when full, their car would need to have a fuel efficiency that matches the airplane's energy expenditure, which would be a car achieving 24 m.p.g., or 9.8 L/100 km.
Historical incidents such as the fueling error with an Air Canada airplane in 1983 demonstrate the importance of carefully monitoring fuel measurements and using the correct units. This incident resulted in an emergency landing when the plane unexpectedly ran out of fuel because of a confusion between pounds and kilograms.
In understanding the consumption of fuel for air travel, it's pertinent to recognize that while a single airplane may get less than one mile per gallon overall, the per-passenger fuel consumption is much higher when the plane is fully occupied. However, this efficiency decreases as the number of occupants drops, illustrating the influence of passenger load on per-passenger fuel efficiency.