Ron Rosenfeld wrote
Are you of the opinion that the IFR charts suggest that when on a random
route and NE of ALIKE (but south of the BJC 090 radial) that 7300 is a
perfectly OK altitude to use?

My teaching has been that when not on a "solid black line" or receiving
radar vectors from ATC, to not go below the MSA, OROCA, etc., for that
area.

The relevant regulation is 91.177 - other than when on approach, 1000
ft above any obstacles within 4 nm of course, or 2000 in designated
mountainous areas. If you meet that, you're complying with 91.177.
The question is how to best comply with this?

On a solid black line, the altitude is published. On vectors, it's
ATC's responsibility. On a random route, it's your responsibility -
sort of. It is relatively common (at least in my neck of the woods)
to have approaches where the FAC is not depicted on the controller's
scope. In this situation, RADAR services are available, but vectors
to final are not. It's fairly common (in my experience) to get a
clearance direct to the IAF (NOT a vector) at an altitude lower than
anything published - OROCA, MSA, or even the published minimum
altitude for crossing the FAF. Clearly the controller is using his
MVA for this. Are you suggesting that accepting such a clearance is
improper?

Even without RADAR services, it's not all that clearcut. Certainly if
you maintain OROCA or MSA, you're complying, and in many cases this is
the way to go. However, this is often not practical. For example, in
my next of the woods there are tethered balloons going to 15000 ft,
and that makes OROCA just over 16000 for the sector. This would make
direct routings impossible for anyone without turbos. In reality, the
minimum altitudes for direct routings in most of that sector are in
the 2000-4000 range.

I've seen a similar situation apply to the MSA, where an entire sector
had an MSA about 1500 ft higher than it would have been had it not
been for ONE tower, about 23 nm away from the fix. I have to believe
that in mountainous terrain, this is even more common, since airports
tend to be in valleys.

Under Part 91, there is really no defined requirement for where the
data you use to comply with 91.177 should come from. However, I have
to believe that any FAA-recognized chart is fair game. I have no idea
if 7300 is OK in the area you describe, because I have not seen the
relevant VFR chart. It might be. If the obstructions that make the
MSA in the sector 10,500 are 20 miles away, and the local terrain is
much lower, then maybe it is. However, with only the infomation on
the approach plate, I sure wouldn't try it.

Michael