I'm just curious if it's ever possible to file for, and/or fly, an altitude that is above an airway restriction. Say if the airway has an altitude restriction of FL410 or less. Is it ever possible to fly above that (with a capable plane, of course)? Thanks!
MAA ( Maximum Authorized Altitude) for an airway is the highest authorized altitude to be flown on that particular airway/published route. Usually this limitation is to ensure adequate navigation signals. It's published on the IFR enroute chart for the airway/published route to which it applies. You can't fly along this airway/published route (using your own navigation equipment as the primary source) at an altitude higher than published (i.e., the MAA if one exists). Point-to-point RNAV (random-not using a published route) does not have an MAA.
Look at the IFR Enroute chart legend for the definition of MAA (Maximum Authorized Altitude) .