IFR below OROCA

[simtech]

I'm doing a short IFR flight tomorrow, about 50 miles. The OROCA in my quadrant is 3500 and in the destination quadrant it is 3800. This is non mountainous terrain. On the VFR chart the same quadrants are 1800. I'm going direct and wondering if I file 3000 will ATC be okay with that you think or to be safe File 4000 even though its the wrong direction. I don't want to climb to 5kft for a 30 minute flight. But will I have too. Any input?? it will not be in IMC except maybe a passing through a cloud here and there. No overcast.

 

[Gucci Pilot]

As long as the minimum vectoring altitude is 3,000 or below they will be fine with it. Usually short flights like that, they are ok giving you opposite direction altitudes. All depends on the controller.

 

[poadeleted20]

The OROCA is there only for informational purposes. ATC will assign an altitude which complies with their handbook and 91.177, and neither mentions the OROCA as a determinant. Your best bet to get a fast answer would be to call your local TRACON and ask them what to expect.

 

[Clark1961]

minimum vectoring altitude will control, maybe call the controlling agency to see what they can do for you

 

[simtech]

Thanks for the info. Ill plan at 3k and I'm sure when I get my clearance ill know for sure. I was just unsure if that was even possible to do. So Ill learn tomorrow. I'm flying into an airshow so I figured Id go IFR, that might help with them knowing I'm coming. When I leave Ill go VFR, Likely get out of there faster. Sure I can drive there in an hour, and the plane will take that long to get ready, load, and fly there, and cost more, BUT it will be WAY more fun!

 

[Shawn]

I had a similar situation (although in "mountainous terrain") and my CFI taught me a trick...

We were flying IFR flying direct at 3000' in extreme VMC. ATC comes on and says basically need you to climb to 4000' or change heading 20 degrees left for the 2000' terrain clearance for that quadrant.

CFI had me respond with "terrain in sight, request to maintain 3000' and current heading"...and we were cleared to stay where we were.

Now we were WELL clear of any terrain and in VMC as mentioned. By taking responsibility for our own terrain avoidance we were able to proceed below their minimum altitudes for that sector.

 

[roncachamp]

I'm doing a short IFR flight tomorrow, about 50 miles. The OROCA in my quadrant is 3500 and in the destination quadrant it is 3800. This is non mountainous terrain. On the VFR chart the same quadrants are 1800. I'm going direct and wondering if I file 3000 will ATC be okay with that you think or to be safe File 4000 even though its the wrong direction. I don't want to climb to 5kft for a 30 minute flight. But will I have too. Any input?? it will not be in IMC except maybe a passing through a cloud here and there. No overcast.

ATC doesn't care about OROCAs, they will assign an altitude at or above the MVA/MIA. OROCAs are fixed in dimension while MVA/MIAs are tailored so OROCAs are higher than the minimum IFR altitude. Generally, the lowest altitude that will be assigned to an enroute aircraft is the MVA/MIA rounded up to the next cardinal altitude, if necessary, plus 1000 feet so as not to shut down IFR operations at other airports along the route, plus possibly another 1000 feet for direction of flight. The shorter the flight the less the last two come into play.

 

[roncachamp]

I had a similar situation (although in "mountainous terrain") and my CFI taught me a trick...

We were flying IFR flying direct at 3000' in extreme VMC. ATC comes on and says basically need you to climb to 4000' or change heading 20 degrees left for the 2000' terrain clearance for that quadrant.

CFI had me respond with "terrain in sight, request to maintain 3000' and current heading"...and we were cleared to stay where we were.

Now we were WELL clear of any terrain and in VMC as mentioned. By taking responsibility for our own terrain avoidance we were able to proceed below their minimum altitudes for that sector.

That trick ain't permitted.

 

[peerlesscowboy]

I'm doing a short IFR flight tomorrow, about 50 miles. The OROCA in my quadrant is 3500 and in the destination quadrant it is 3800. This is non mountainous terrain. On the VFR chart the same quadrants are 1800. I'm going direct and wondering if I file 3000 will ATC be okay with that you think or to be safe File 4000 even though its the wrong direction. I don't want to climb to 5kft for a 30 minute flight. But will I have too. Any input?? it will not be in IMC except maybe a passing through a cloud here and there. No overcast.

What'll be the highest obstacle within 4 nm of your route? Add 1000', round up to the nearest thousand and file that. If ATC needs you higher they'll let you know.

 

[poadeleted20]

minimum vectoring altitude will control,

Not necessarily. Might be the Minimum IFR Altitude rather than the MVA -- the two are not synonymous.

c.​

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Random routes.​

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When not being radar monitored,​

GNSS-equipped RNAV aircraft on random RNAV​

routes must be cleared via or reported to be​

established on a point-to-point route.​

(a)​

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The points must be published NAVAIDs,​

waypoints, fixes or airports recallable from the​

aircraft’s navigation database. The points must be​

displayed on controller video maps or depicted on the​

controller chart displayed at the control position.​

When applying nonradar separation the maximum​

distance between points must not exceed 500 miles.​

(b)​

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Protect 4 miles either side of the route​

centerline.​

(c) ​

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Assigned altitudes must be at or above the​

highest MIA along the projected route segment being​

flown, including the protected airspace of that route​

segment.​

2.​

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Impromptu​

PHRASEOLOGY​

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DIRECT (name of NAVAID/waypoint/fix/airport)​

NOTE​

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A random impromptu routing is a direct course initiated by​

ATC or requested by the pilot during flight. Aircraft are​

cleared from their present position to a NAVAID, waypoint,​

fix, or airport.​

3.​

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Point-to-Point​

PHRASEOLOGY​

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After (fix) proceed direct (fix)​

NOTE​

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A point-to-point route segment begins and end

 

[ErikU]

I'd ask for VFR on top. That has worked for me in the past.

 

[Clark1961]

Not necessarily. Might be the Minimum IFR Altitude rather than the MVA -- the two are not synonymous.

The practical answer around here is you'll either be on an airway or you'll be on radar.

 

[roncachamp]

I'd ask for VFR on top. That has worked for me in the past.

VFR-on-Top does not permit flight below the minimum IFR altitude.

 

[poadeleted20]

The practical answer around here is you'll either be on an airway or you'll be on radar.

Perhaps where you are, but it's not universally true, so the practical answer where the OP is might be different.

 

[Clark1961]

Perhaps where you are, but it's not universally true, so the practical answer where the OP is might be different.

Might be, might not be - I'm quite willing to bet that it is the most common case since it reduces controller workload and center controllers get spread pretty thin these days.

 

[poadeleted20]

Might be, might not be - I'm quite willing to bet that it is the most common case since it reduces controller workload and center controllers get spread pretty thin these days.

Most common? Maybe in terms of number of operations, but not, I think, in terms of geographic area. In any event, the book says MVA/MIA, so it may be either, depending on where the operation takes place.

 

[simtech]

Well I filed for 3k direct. And they gave it to me no problem. Was an easy IFR flight until I got to the airshow. Very busy getting in.