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)