MOCA and MEA over water???

Steven P. McNicoll wrote:

VORs tend to be built
on land.



Oh, then you haven't seen those new whale-mounted VOR's ? The problem
is they are NOTAM'd as "always intermittent".

Antonio ;-)

"Antoñio" wrote in message
...
yupyupxav wrote:
I guess for MEA, if you fly lower, you might not get navigational
coverage or radio recacption with the center... It might be for other
things than Terrain...

Wouldn't it be called out as a MRA rather than an MEA ?

No.
MEA is defined for an airway segment, and at that altitude you are assured
to be able to get the VORs that define the airway. However, this altitude
may not be enough to get other VOR that defines an intersection. The
altitude at which you can define an intersection is called MRA, and it is
defined for the intersection. It has to be higher than MEA.


guillermo

MRA is an intersection reception altitude.



"Antoñio" wrote in message
...
yupyupxav wrote:
I guess for MEA, if you fly lower, you might not get navigational
coverage or radio recacption with the center... It might be for other
things than Terrain...

Wouldn't it be called out as a MRA rather than an MEA ?

Antonio

We seem to have wandered a bit (not that that's a bad thing), but I feel
the need to ask my original questions again.

1) Why is there a 2000 MOCA out over the ocean?

2) Why do the MEA's around PREPI get lower as you get further from the VOR?

1) Why is there a 2000 MOCA out over the ocean?

Are there perhaps offshore installations of some sort? Weather
stations? I know MOCA's are 1500 on the Q-routes over the Gulf, since
the oil platforms are sometimes 400+ ft tall at the tallest (antenna)
points.

2) Why do the MEA's around PREPI get lower as you get further from
the VOR?

I would like to know what MEA's mean offshore in the first place. The
MEA's on the Q-routes are 6000 ft. Why? They're not VOR based. You
can't get anything like consistent radio reception at 6000 (or 11000
for that matter) - you're always given lost comm instructions and relay
through airliners. There's no RADAR coverage. So why 6000 and not
2000? Haven't figured it out yet.

Michael

Michael wrote:
1) Why is there a 2000 MOCA out over the ocean?

Are there perhaps offshore installations of some sort?

Not that I'm aware of. The tallest thing I can think of is something
like Ambrose Tower (http://www.njlhs.burlco.org/ambrose.htm), but it's
under 200 feet and in any case, these things are usually just a few
miles offshore; I've never heard of one being built 50 miles out in
the Atlantic.

"Roy Smith" wrote in message
...

Not that I'm aware of. The tallest thing I can think of is something
like Ambrose Tower (http://www.njlhs.burlco.org/ambrose.htm), but it's
under 200 feet and in any case, these things are usually just a few
miles offshore; I've never heard of one being built 50 miles out in
the Atlantic.


The Texas Towers radar sites were out further than that, but they weren't
that tall.