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.

AIM
4-4-7. IFR Clearance VFR-on-top

a. A pilot on an IFR flight plan operating in VFR weather conditions, may
request VFR-on-top in lieu of an assigned altitude. This permits a pilot to
select an altitude or flight level of their choice (subject to any ATC
restrictions.)

....

e. When operating in VFR conditions with an ATC authorization to "maintain
VFR-on-top/maintain VFR conditions" pilots on IFR flight plans must:

1. Fly at the appropriate VFR altitude as prescribed in 14 CFR Section
91.159.

2. Comply with the VFR visibility and distance from cloud criteria in 14
CFR Section 91.155 (Basic VFR Weather Minimums).

3. Comply with instrument flight rules that are applicable to this flight;
i.e., minimum IFR altitudes, position reporting, radio communications,
course to be flown, adherence to ATC clearance, etc.

....

--------------------------------


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