MEA, MORA, MOCA???
Morten Schnack Sillesen
Can anyone explain the difference between MEA, MOCA and MORA to me? My
instructor really messed up the other day, so now I'm totally
confused.
Regards, Morten
---
Morten Schnack Sillesen phone (GSM): +45 40 21 23 39
Copenhagen email: sill...@post6.tele.dk
Denmark http://home6.inet.tele.dk/sillesen/
Roy Smith
Briefly:
The MEA (Minimum Enroute Altitude) gives you terrain clearance and navaid
reception along an airway.
The MOCA (Minimum Obstacle Clearance Altitude) give you terrain clearance
along an airway, but you may be too low to receive the navaids properly.
The MORA (Minimum Off Route Altitude?) is essentially the MOCA of an entire
area, off the airways.
--
Roy Smith <r...@popmail.med.nyu.edu>
New York University School of Medicine
Copyright 1997 Roy Smith
For-profit redistribution prohibited
Matt Dossey
I'd suggest using the AIM glossary. You can access the AIM through
http://www.landings.com
If you still can't find it, email me and I'll help you out.
MD
leon...@aol.com
In article <3304fa0...@news.inet.tele.dk>, sill...@post6.tele.dk (Morten Schnack Sillesen) writes:
>Can anyone explain the difference between MEA, MOCA and MORA to me? My
>instructor really messed up the other day, so now I'm totally
>confused.
In the US, the MEA (minimum en route altitude) is the lowest altitude which provides both obstacle clearance and reception of the navaids defining the route, over the entire route segment (but see another recent thread for exceptions to the navaid reception guarantee: airways may have gaps in nav signal coverage in some circumstances).
The MOCA (minimum obstacle clearance altitude) is the lowest altitude which provides IFR standard obstacle clearance, and also provides reception of the defining navaids (VORs) within 22 nm of the VOR.
The MRA (minimum [off-route?] reception altitude) is the lowest altitude which provides reception of off-route navaids which may be used to identify intersections.
MOCA is always less than or equal to MEA. If equal, it is not reported.
MRA is always greater than or equal to MEA. If equal, it is not reported.
The MEA is usually the minimum legal altitude when flying airways. However, if you are within 22nm of the VOR, you can go down to the MOCA.
As far as I know, MRA is not regulatory. I assume that a pilot would be expected to request MRA or higher if he needed to identify an intersection, and did not have DME or IFR GPS to do it.
None of these designated altitudes has anything to do with radar coverage or radio communications.
These definitions may be slightly different under ICAO.
Marc Leonard
Leon...@aol.com
Kevin Martin
You have the MRA correct but he asked for MORA which is the Minimum
Off Route Altitude. The MORA is currently printed on Jepps enroute
charts in the respective quadrant similar to a VFR Chart MOCA. It
provides IFR terrain clearance.
Kevin
In article <19970216060...@ladder01.news.aol.com>,
leon...@aol.com says...
James R Negris
In the newer versions of the AIM (starting in 1996, I think), OROCA
(Off-Route Obstruction Clearance Altitute) is used, not MORA. Maybe
MORA is a Jepp convention?
James
Morten Schnack Sillesen wrote:
>
> Can anyone explain the difference between MEA, MOCA and MORA to me? My
> instructor really messed up the other day, so now I'm totally
> confused.
>
Gene Hudson
sill...@post6.tele.dk (Morten Schnack Sillesen) wrote:
>Can anyone explain the difference between MEA, MOCA and MORA to me? My
>instructor really messed up the other day, so now I'm totally
>confused.
>Regards, Morten
>---
>Morten Schnack Sillesen phone (GSM): +45 40 21 23 39
>Copenhagen email: sill...@post6.tele.dk
>Denmark http://home6.inet.tele.dk/sillesen/
MEA = Minimum Enroute Altitude. Guarantees terrain clearance and
radio reception of the centerline of the airway, not the cross
radials.
MORA = doesnt exist, suspect you are referring to MRA; published for
specific fixes; defines an altitude above the MEA, below which you
cannot receive the cross radial and cannot therefore identify the fix.
Minimum Reception Altitude.
MOCA = Minimum Obstacle Clearance Altitude; guarantees terrain
clearance, but not radio reception, except that radio reception of the
airway centerline is guaranteed within 22NM of each end of the airway.
Regards,
Gene
P.S. If your instructor does not know this, well, good luck.
