Here it is, Greg...and they do say in this interpretation that Flight Instruction IS commercial flying. Which would seem to contradict what was said in the Fretwell letter.
I'm confused...and it ain't the first time
Actually, what they say is that flight instruction for compensation is "other commercial flying" in the context of duty time limits for commercial operations. That definition is limited to that context, just as the issue of what level of medical certification is required to give flight training is limited to the context of 14 CFR 61.23. The FAA Chief Counsel has long made clear that these letters apply only to the question/regulation they discuss, and not to other questions or other regulations not asked or discussed.
And thanks to Greg for finding that letter which I failed to find. It leads directly to the
Martindell letter, which in paragraph 2 certainly makes clear that the ALPA statement is in direct contradiction with the FAA Chief Counsel's position. There is nothing in either the Martindell or Johnstone letters which says that "other commercial flying" is limited to flying covered by Part 117, only that the duty time limits against which "other commercial flying" counts are those duty time limits in operations covered by Part 117.
So, it clearly states that the answer to the original question at the top of this discussion is
yes, the FAA's stated position is this flight training for compensation
does count against your 121.471 limits, no matter what ALPA's attorneys or Jonesy's company say.
Also, when dealing with FAA definitions, keep in mind that they have three different definitions of "night" depending on whether you're talking about lights, landing currency, or logging night time, and seven different definitions of "cross-country time", again depending on context. And they even have a definition of "pressurized aircraft" in 14 CFR 61.31 which, for the purposes of that section
and only that section, includes quite a few unpressurized aircraft (like the Beech V35TX and the Cessna 401) but excludes many aircraft with cabin pressurization (like the Piper Malibu). So yes, context is critical.