Text in force at CS25-28: from CS25-0, effective 17 Oct 2003.
(See AMC 25.815) The passenger aisle width at any point between seats must equal or exceed the values in the following table: Minimum passenger aisle width (cm (inches)) Passenger seating Less than 64 cm capacity 64 cm (25 (25 inches) inches) from floor and more from floor 10 or less 30 (12)* 38 (15) 11 to 19 30 (12) 51 (20) 20 or more 38 (15) 51 (20) * A narrower width not less than 23 cm (9 inches) may be approved when substantiated by tests found necessary by the Agency.
ED Decision 2003/002/RM · Source