A session in a simulator, FTD or other device is not a “flight”. The confusion that leads to this frequently asked question comes about because there are a number of different definitions here. And “total time” is not one of them.
“Total Time” isn’t defined anywhere in the FAR. When the term is used, it’s not alone. For example, 61.109(a) requires 40 hours of “flight time” for the private certificate. On the other hand, the 61.159 aeronautical experience requirements for the ATP include “at least 1,500 hours of total time as a pilot” So there’s really no such thing as “TT” standing by itself. It’s usually combined with either “pilot time” or “flight time”. There is a world of difference between the two.
“Pilot time” is defined in 61.1(b)(12) and specifically includes simulator time.
that time in which a person – (i) Serves as a required pilot flight crewmember; (ii) Receives training from an authorized instructor in an aircraft, flight simulator, or flight training device; or (iii) Gives training as an authorized instructor in an aircraft, flight simulator, or flight training device.
On the other hand, “flight time” is defined in FAR 1 as
Pilot time that commences when an aircraft moves under its own power for the purpose of flight and ends when the aircraft comes to rest after landing…
That does not include simulators. Even the best of them are not “aircraft.” They sit on the ground.
The bottom line in terms of what one writes in their logbooks is part regulatory and part bookeeping.
The regulatory part: Nothing that you are tracking to meet a “flight time” requirement or time a category, class, or type of “aircraft” should include time in a training device that sits on the ground. If you think it’s valuable, and I suspect such things as time in a full motion Level D 737 simulator are, track them separately.
The bookkeeping part: The logbooks I’ve seen don’t have a “total time” column. I’ve generally seen total “flight” time or “Total duration of flight,” and device time doesn’t belong there. If you really have a plain “total time” column, I guess you can treat it either way. But keep in mind, any column in which you combine them will have to be separated out the next time you fill in an 8710 application for a new certificate or rating and, probably, for other purposes as well.