What's a Grid MORA?

[j328ernest]

I think MORA still means the Minimum Off-Route Altitude with that value only offering obstacle clearance in either mountainous or non-mountainous terrain - but no guarantee for navigation or comm.
So would the Grid number be that large number depicted in any one quadrangle on the Jepp chart? I think they're shown as green below 14,000 and magenta above it.

Am I correct?

 

[Alchemy]

Yes. My CFI was asked this very question during his interview at Expressjet. We looked it up afterwards and it is the two digit number in the middle of each lat/long quadrangle.

On a sectional it's a maximum elevation figure, on an L chart it's the grid mora.

 

[Mmmmmm Burritos]

Correct. MORA and grid MORA are the same thing on Jeppesen charts. On the FAA/NOS/NACO/NOAA (whatever you want to call them) charts, it's known as the MOROCA.

1000 ft terrain/obstacle clearance which rises to 2000 ft clearance in a mountainous area. That's above the highest obstacle in that charted grid area.

The MEF on a VFR sectional chart is the same idea, but nowhere near the same altitude clearance. The MEF numbers guarantee you at least 101 ft of clearance. That is, they round up the obstacle height to the nearest 100 ft then add a 100 ft buffer for manmade objects or a 200 ft buffer for natural objects (hills).

 

[bigsky]

Moca= Min obstruction clearance along airway and does give navaid reception within 22 NMs. (T)

Route Mora= min off route altitude designed to assure obstruction clearance for 10 miles either side of centerline (A)

Grid mora is obstruction clearance of 1000 or 2000 when altitude is approximately 5000 or greater( Jepps version of mountainous) and applies for that grid of lat/long-