If you schedule training events at a Part 142 center, the qualification level of the device you book is not a detail — it determines whether the FAA will accept the training credit at all. Here is the plain-English version.
What FSTD means
FSTD — Flight Simulation Training Device — is the FAA umbrella term covering full-flight simulators (FFS), flight training devices (FTD), and aviation training devices (ATD). The FAA qualifies each device individually, and the qualification level sets what training it can be used for.
The levels that matter
Level D FFS is the top tier — full motion, full visual — and qualifies for zero-flight-time initial type ratings. Level C is similar with lower visual fidelity, common for recurrent. Level 6/7 FTDs are high-fidelity, typically without full motion. Level 4/5 are procedure trainers. Each tier accepts different training events.
Why scheduling has to know this
Booking a Level 5 FTD for a maneuver that requires Level D credit is a compliance failure that can void the training. A scheduler should never have to memorize the matrix — the software should reject a device whose qualification does not match the approved curriculum event.
Qualifications expire, too
FSTDs are re-qualified by the FAA on a schedule. A good system blocks scheduling on a device whose qualification has lapsed. AviationAlley treats device qualification as first-class — see the FSTD overview.