Depends on what kind of plane you take. I have been on planes that have as few as 6 seats, and as many as 300.
There are 20 ABC seats available on the plane.
There are 20 ABC seats available on this plane.
74
252
188.
The number of available seats on the ABC DEF plane for booking on our flight is 150.
The plane's seats...
250 - 290
An Airbus A380 has 853 passenger seats. These seats are actually used by passengers only if the whole plane has Economy Class configuration. If the plane has a regular three Class configuration, then only 555 will board the plane maximum.
On a standard 747 jumbo jet, there are 420 seats.
Some airplanes have but one seat; some have hundreds.
The plane cary 555 passengers and crew.