Originally Posted by
rickair7777
141 Instructor annual checks are a regulatory requirement...since you cannot conduct a 141 annual check without the chief pilot (or Asst CP/ check instructor), that person is obviously a required crewmember for the mission at hand. Same with 121.
No. I don't think that's how it works. You can't do =any= lesson without an instructor. You can't do an FAA checkride without an examiner or DPE. You can't do a BFR or an IPC (a regulatory requirement) without an instructor That doesn't make an instructor or a DPE a required "pilot" crewmember. If it did, then (a) CFIs would always be required to have a current medical and (b) there would be no need for the rule that CFIs log PIC by the act of providing instruction.