Definition
The lowest published altitudes along an RNAV Q-route in the high-altitude structure (FL180 through FL450) that guarantee both acceptable navigation signal reception for area navigation and obstacle clearance along that segment. Q-routes are RNAV-only airways available to aircraft equipped with approved area navigation systems (typically GPS or DME/DME/IRU), and their MEAs apply specifically to those routes rather than to conventional VOR airways.
Plain English
The lowest altitude you are allowed to fly on a high-altitude RNAV airway (a Q-route). Stay at or above this altitude and you'll have safe terrain clearance and reliable navigation along that segment.
Context Anchor
Seen on IFR en route high altitude charts along RNAV Q-routes, usually next to or near the route segment they apply to.
Derivation
MEA stands for Minimum En Route Altitude. 'Q' is the FAA's letter designator for high-altitude RNAV airways, the same way 'V' designates conventional low-altitude VOR airways. The 'Q' itself has no special meaning — it was simply assigned as the identifier for this class of route.
Why Pilots Care
Compliance ensures safe navigation performance and terrain clearance while using RNAV procedures in high-altitude airspace.
Intuition Check
“Minimum” does not mean “best” or “most efficient” altitude here. It means the lowest published altitude that is allowed for that route segment under IFR.
Example Sentence 1
Cleared direct ZAVER then via Q-146, the crew checked the Q-route MEAs on the high-altitude chart before requesting their cruise altitude.
Example Sentence 2
ATC assigned a Q-route at or above the published RNAV Q-Route MEAs to maintain navigation accuracy.