RNAV MAA and MEA

[Chief Captain]

Looking at the L24 en-route chart, I'm trying to figure out why an RNAV route would have an MEA and/or an MAA. Take the T208 and T211 for example. Shouldn't you be safe as long as you're above the OROCA?

 

[dustoff17]

MAA and MEA are not always published for reception of navigation equipment. Some of them are for RADAR coverage or service area overlap and/or for radio reception. You'll find some that are relatively high in order to communicate with FSS.

 

[Barty]

... for radio reception.

This. Since it is a published route, radar coverage isn't important and could be flown legally in a non-radar environment.

 

[dustoff17]

This. Since it is a published route, radar coverage isn't important and could be flown legally in a non-radar environment.

Good point. I stand corrected - Thanks Barty

 

[Chief Captain]

Ok, so I get that the MEA is for communication, but what about the MAA?

 

[dustoff17]

Maximum authorized altitude (MAA). A published altitude representing the maximum usable altitude or flight level for an airspace structure or route segment.

Could be for the same reason...communication.

Or, and I'm not familiar with the route your talking about, it could be unpublished overlying airspace (i.e. military/government operations). I don't think that GPS plays a part in this.

 

[bLizZuE]

I didn't look, but you mentioned that they were T routes. These routes are defined as low level Terminal routes. They are always below 15000 feet.