Originally Posted by Toonces

No idea, I was asking the question.

There are way too many scenarios, but imagine if a civilian pilot was being trained in a military aircraft by a military instructor pilot as part of his job as a contractor. The military instructor pilot has no requirement to hold an FAA flight instructor certificate, so is this time loggable?

Part 61.1 defines who an authorized instructor is, and Part 61.51 says that training time is only loggable by an authorized instructor. A military instructor pilot is not mentioned in either of these. Did the training even happen?