ORCA lower than MEA?

Ron Rosenfeld wrote:

On 21 Jan 2007 21:51:03 -0800, "Dan" wrote:


There are some places on IFR enroute charts where the OROCA (Off-route
obstruction clearance altitude) is actually lower than MEAs on an
airway in the same quadrant. The higher MEA is NOT due to obstacles in
adjacent quadrants.

If I'm on the airway, usually they don't let folks go down to the MOCA,
however if I file direct off-airways, how likely am I to be able to get
the ORCA? The goal is trying to stay below oxygen altitudes in
mountainous terrain while remaining IFR.

--Dan


Although I've never done it, I have read that in that sort of area you
could request "VFR-on-top". There is no requirement that this sort of
flight be carried out *over* an undercast.

But, it has to be at, or above the minimum IFR altitude, plus comply
with the VFR altitude rules. Often, that forces you higher than MEA.

"Sam Spade" wrote in message
...
Newps wrote:


Sam Spade wrote:

Newps wrote:



Sam Spade wrote:

Dan wrote:

I don't suppose this MIA information is avaliable or published
somewhere is it? It would be useful for flight planning.

No, they guard that stuff like it belongs only to them.







More drivel.



Rather than just making such a cavalier statement, why not be positive
and point us pions to the public source for MIA charts.


I have no idea if there is a website with all the data. I have
occasionally come across various MVA or MIA maps online. But nobody
guards it as it isn't sensitive. Stop by any facility and they'll make a
copy for you.

There is no web site with MIA data. I had to make a Freedom of
Information Act request to get MIA data for a couple centers. The group I
work with had the same problem with MVAs, but got those loosened up.

What you are saying is true, but it means stopping by the facility with
one's hat in their hand. That does not help the OP at all.

There's a lot of stuff that's not on the web. So what? Not everything
justifies the time, energy, money, and bandwidth needed to put it on the
web.

Then there's the issue of keeping it current. MVAs and MIAs, along with
LOAs, SOPs, and a myriad of other pieces of paper (or computer files) are
internal facility documents that change, require review at periodic
intervals, or simply get cancelled. What happens when some stick actuator
reads (or mis-reads) the outdated MVA chart he pulled off the web and flies
into the new cell phone transmission tower?

MVAs and MIAs aren't classified. They're probably not even FOUO. But just
because they're not on the web or in your local library branch doesn't mean
there's some evil conspiracy to keep them from the public.

All you have to do is ask.

KP wrote:


There's a lot of stuff that's not on the web. So what? Not everything
justifies the time, energy, money, and bandwidth needed to put it on the
web.

Then there's the issue of keeping it current. MVAs and MIAs, along with
LOAs, SOPs, and a myriad of other pieces of paper (or computer files) are
internal facility documents that change, require review at periodic
intervals, or simply get cancelled. What happens when some stick actuator
reads (or mis-reads) the outdated MVA chart he pulled off the web and flies
into the new cell phone transmission tower?

MVAs and MIAs aren't classified. They're probably not even FOUO. But just
because they're not on the web or in your local library branch doesn't mean
there's some evil conspiracy to keep them from the public.

All you have to do is ask.



Repeating myself: I had to FOIA the E-MSAW data for Denver, Salt Lake
City, and Los Angeles Centers. Even then, I received a telephone call
asking "20 questions" before they would release the data.

E-MSAW is the only way to reconstruct MIA sectors because, unlike MVAs,
there are not video map files for MIAs. In my FOIA I first requested
the actual MIA maps for ZLA, and was quoted a charge of $14,000.

No doubt, MVA and MIA data would be useless unless it is both current
and georeferenced in a pilot-friendly format. Since those data are
always current for centers and TRACONs, they certainly could be made
available in a current form for pilots, just like sectionals, IFR
charts, and electronic nav databases.

MIAs and MVAs are, in fact IFR altitudes that avoid Part 95 rule-making
and real public scrutiny.

Sam Spade wrote:


E-MSAW is the only way to reconstruct MIA sectors because, unlike MVAs,
there are not video map files for MIAs. In my FOIA I first requested
the actual MIA maps for ZLA, and was quoted a charge of $14,000.


I can believe that. The last time we redrew the map it took one of our
guys a month or so to do it. It is not in an electronic format such as
a jpg. The MVA chart is drawn on a sectional and mailed to the people
who handle this with all the supporting documents. These people then
look at it and approve it and mail us back the electronic maps that get
installed in the system. It's pretty comical how much work that goes
into it.



No doubt, MVA and MIA data would be useless unless it is both current
and georeferenced in a pilot-friendly format. Since those data are
always current for centers and TRACONs, they certainly could be made
available in a current form for pilots, just like sectionals, IFR
charts, and electronic nav databases.


Sure they could but it's not in a useable format now. And ATC doesn't
need it in that format, only you do. Thus the high price.



MIAs and MVAs are, in fact IFR altitudes that avoid Part 95 rule-making
and real public scrutiny.


So what?

Newps wrote:



Sam Spade wrote:


E-MSAW is the only way to reconstruct MIA sectors because, unlike
MVAs, there are not video map files for MIAs. In my FOIA I first
requested the actual MIA maps for ZLA, and was quoted a charge of
$14,000.



I can believe that. The last time we redrew the map it took one of our
guys a month or so to do it. It is not in an electronic format such as
a jpg. The MVA chart is drawn on a sectional and mailed to the people
who handle this with all the supporting documents. These people then
look at it and approve it and mail us back the electronic maps that get
installed in the system. It's pretty comical how much work that goes
into it.



No doubt, MVA and MIA data would be useless unless it is both current
and georeferenced in a pilot-friendly format. Since those data are
always current for centers and TRACONs, they certainly could be made
available in a current form for pilots, just like sectionals, IFR
charts, and electronic nav databases.


Sure they could but it's not in a useable format now. And ATC doesn't
need it in that format, only you do. Thus the high price.



MIAs and MVAs are, in fact IFR altitudes that avoid Part 95
rule-making and real public scrutiny.



So what?

That is my point; the ultimate ATC response when out of phony answers.

Some folks like to know independent of the reassuring voice of Mr.
Goodscope that the IFR altitude in use is actually safe. There are dead
pilots that could have benefited greatly had they had that information.

Newps wrote:



I can believe that. The last time we redrew the map it took one of our
guys a month or so to do it. It is not in an electronic format such as
a jpg. The MVA chart is drawn on a sectional and mailed to the people
who handle this with all the supporting documents. These people then
look at it and approve it and mail us back the electronic maps that get
installed in the system. It's pretty comical how much work that goes
into it.

That drawing on a sectional is going to be history soon. Your friends
in DC have finally developed an automated CAD tool to design MVAs and MIAs.

On Tue, 23 Jan 2007 05:20:03 -0800, Sam Spade wrote:

Ron Rosenfeld wrote:

On 21 Jan 2007 21:51:03 -0800, "Dan" wrote:


There are some places on IFR enroute charts where the OROCA (Off-route
obstruction clearance altitude) is actually lower than MEAs on an
airway in the same quadrant. The higher MEA is NOT due to obstacles in
adjacent quadrants.

If I'm on the airway, usually they don't let folks go down to the MOCA,
however if I file direct off-airways, how likely am I to be able to get
the ORCA? The goal is trying to stay below oxygen altitudes in
mountainous terrain while remaining IFR.

--Dan


Although I've never done it, I have read that in that sort of area you
could request "VFR-on-top". There is no requirement that this sort of
flight be carried out *over* an undercast.

But, it has to be at, or above the minimum IFR altitude, plus comply
with the VFR altitude rules. Often, that forces you higher than MEA.

I've not flown extensively in mountainous areas. Are there really many
airways with MEA's below the minimum 91.177 IFR altitudes for flight?

Or are you saying that ATC would not grant the clearance because of radar
coverage/MIA/MVA issues?


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

Ron Rosenfeld wrote:


I've not flown extensively in mountainous areas. Are there really many
airways with MEA's below the minimum 91.177 IFR altitudes for flight?

There used to be only one choice for On Top. Fly a Victor Airway at a
compliant VFR altitude, and not less than the MEA. Since MEAs are
almost always at X-thousand, you have to fly higher than that to be at a
VFR altitude.

Now, with RNAV-direct common, you have to fly at, or above, the Center's
MIA at a VFR altitude. This, of course, provided the controller will
give you the MIA. ;-)

As to you providing your own 91.177 altitude that just won't work in
controlled airspace if it is lower than the MIA.

Or are you saying that ATC would not grant the clearance because of radar
coverage/MIA/MVA issues?

MIA issues and often radar coverage.

Sam Spade wrote:


Some folks like to know independent of the reassuring voice of Mr.
Goodscope that the IFR altitude in use is actually safe. There are dead
pilots that could have benefited greatly had they had that information.



They are not dead because the MVA/MIA altitude was bad. That has never
happened.

Ron Rosenfeld wrote:



I've not flown extensively in mountainous areas. Are there really many
airways with MEA's below the minimum 91.177 IFR altitudes for flight?

Or are you saying that ATC would not grant the clearance because of radar
coverage/MIA/MVA issues?


We have lots of airways whose MEA's are well below the peaks of the
mountains, 4-5000 feet below. A lot of airways zig zag to get into the
low areas or passes between mountains. Some just go right over the top.
As for OTP we don't care about radar coverage. We use OTP everyday
here, more in the winter than the summer. We don't care what altitude
you go at. MVA/MIA is also irrelavant for OTP ops.