Big Duke Six said:
A Squared: Seems like I'd hear all kinds of 135 guys asking for (and getting) VFR On Top clearances in order to stay below the MEA's through the mountains. Did you say that VFR-OT was not allowed for Part 135 and 91? I don't think that's correct, but I could be wrong.
No, I didn't say that VFR on top wasn't allowed for 135 operators. I said that they couldn't descend below the MEA on a VFR on top clearence whereas part 121 operators may. It's one of hte rare circumstances where part 121 is more permissive that part 135 and part 91. Here's a legal interpretation which explains it.
FAA Legal Opinion:
AGC-23
Interpretation: IFR Operations - VFR on-Top
Chief, Airspace, Air Traffic, and Environmental Quality Branch, AGC-23
ARM-7B
This is in reply to your memorandum containing the following question presented by your Flight Standards Division.
May an aircraft on an IFR flight plan but cleared by ATC to maintain "VFR conditions on-top" (FAR 91.121(a)) be operated below minimum en route IFR altitudes; i.e., without regard to FAR 91.119(A)?
Such operation is not permitted under Parts 91 or 135. It is our opinion that Sec. 91.119 does apply to IFR operations that are clear for "VFR conditions on-top." The minimum altitude rules of Sec. 91.119 are designed to ensure safe vertical separation between the aircraft and the terrain. These minimum altitude rules apply to all AFE flight, whether in IFR or VFR weather conditions, and whether assigned a specific altitude or flight level or "VFR conditions on-top." A pilot operating on a "VFR conditions on-top" clearance may operate at the altitude or flight level of his choice; however, he is required to adhere to Sec. Sec. 91.119 as well as Sec. 91.109 of the FARs. While Sec. 91.121(a) specifically incorporates the VFR flight levels of Sec. 91.109, there is no basis to conclude that Sec. 91.119 does not apply.
Section 121.657, however, provides for an analogous "over-the-top" IFR operation under certain restrictive conditions at minimum altitudes that may be below those prescribed under Part 95.
This interpretation has been coordinated with AFS-800 and AAT-200 who are of the opinion that the regulations do not need clarification in this respect.
RICHARD W. DANFORTH