IFR navigation?

Question

On a High Altitude Enroute chart, when the MEA is not depicted on the airway??

is the mea 18,000?

Answer 1

The MEA will be on the equivalent LO chart.  You can fly the airways lower than 18,000, but you will have to use the LO charts for navigation instead of the HI charts.

Generally there aren't too many mountains that go high enough to have an MEA above 18,000.

Answer 2

You are correct. If the MEA on a Jet route is higher than 18,000 it will be depicted as such, otherwise it is assumed to be FL180.  There are many MEA's in the western US that are above FL180, not for obstacle clearance but for VOR reception, or sometimes to clear restricted airspace.  J-196 has an MEA of FL330 in some places.

Jet routes are sometimes transposed over low altitude Victor airways, but for ATC purposes they are separate routes. Once you descend below FL180 on such a route, the MEA of the Victor airway applies. If the J route does not overlay a Victor airway and you descend below FL180 then technically you are either on a direct routing to a VOR (or some other fix) or a radar vector.

p.s. I have a high altitude chart in front of me now and it specifically states in the title block "for use at and above 18,000' MSL".

Answer 3

Nope

It is simply less than FL180.  The implication is that if you are using a high-altitude chart, you are above FL180, and therefore above the MEA.

Answer 4

Better get out the Jepps and read the introduction!  I always learn a lot by doing that.  Good luck.