Jose wrote:
You have never heard that it would be illegal to request anything?


Ok, you take me too literally. Rather than play games, I've never heard
that it's illegal to request an altitude from ATC. It may be illegal
for ATC to grant that altitude, but illegal to request it? That would
be news to me.

But I'm willing to read news. Tell me more.

Jose
The MOCA was never intended to be an operational altitude. Where is a
large difference between MEA and MOCA the TERPs folks who design airways
have the option to include an MOCA for emergency use. You many not have
VOR reception and you may not be able to speak with ATC.

Then, there is the following:

91.177 Minimum altitudes for IFR operations.
(a) Operation of aircraft at minimum altitudes. Except when necessary
for takeoff or landing, no person may operate an aircraft under IFR below -
(1) The applicable minimum altitudes prescribed in Parts 95 and 97 of
this chapter; or
(2) If no applicable minimum altitude is prescribed in those parts -
(i) In the case of operations over an area designated as a mountainous
area in part 95, an altitude of 2,000 feet above the highest obstacle
within a horizontal distance of 4 nautical miles from the course to be
flown; or
(ii) In any other case, an altitude of 1,000 feet above the highest
obstacle within a horizontal distance of 4 nautical miles from the
course to be flown.

However, if both a MEA and a MOCA are prescribed for a particular route
or route segment, a person may operate an aircraft below the MEA down
to, but not below, the MOCA, when within 22 nautical miles of the VOR
concerned (based on the pilot's reasonable estimate of that distance).

The last paragraph is particulary on-point and is regulatory.

Some of this has morphed in practice because IFR-certified GPS
navigators are way ahead of the FAA ability to react.

Thus, the language in the 7110.65, which I included in my response to
Mitty. But, notice that requires a radar monitor and a lost comm
procedure (if, in fact, that is ever followed is another matter).

The controller is hard-pressed to provide that procedure unless he uses
his MIA, which makes it an MIA route, not an MOCA route.