14 CFR § 29.815 - Main aisle width.
The main passenger aisle width between seats must equal or exceed the values in the following table:
|Passenger seating capacity||Minimum main passenger aisle width|
|Less than 25 inches from floor (inches)||25 Inches and more from floor (inches)|
|10 or less||12||15|
|11 through 19||12||20|
|20 or more||15||20|
1 A narrower width not less than 9 inches may be approved when substantiated by tests found necessary by the Administrator.
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