A Reddit thread in r/flying raises a technical but consequential question about FAR 61.64 and how the Second-in-Command Operating Experience (SOE) exemption applies when a pilot who already holds an unrestricted jet type rating — such as a CE-525 (Citation) or CE-500 — subsequently adds a King Air 350 (BE-9L) type rating. The poster's reading of the regulation suggests that because the King Air 350 is a turbopropeller airplane rather than a turbojet, the pilot may not qualify for the cross-type SOE waiver that typically applies when adding one jet type to another. Under 61.64, the SOE requirement — which mandates supervised operating experience before a newly type-rated pilot can serve as PIC or SIC in that aircraft in certain operations — can be waived if the pilot already holds another type rating obtained under similarly rigorous training standards. The nuance here is that the exemption language in 61.64 is often summarized colloquially as "if you have one type, additional types don't require SOE," but the actual regulatory text ties the exemption to specific categories and classes of aircraft, and jet-to-turboprop transitions may not automatically qualify the way jet-to-jet transitions do.
This distinction matters significantly to working pilots, particularly those in Part 135 and Part 91K (fractional/corporate) operations who frequently cross-train between airframes as their career or company fleet needs evolve. A pilot moving from a light jet like a Citation CE-525 into a King Air 350 — a common career or company-driven transition, since many charter and corporate flight departments operate mixed jet/turboprop fleets — needs to know definitively whether they can go straight into revenue or PIC-qualifying flying after initial or recurrent type-rating training, or whether they must first accumulate supervised SOE hours (commonly 15-25 hours depending on aircraft class and operator OpSpecs) before functioning unsupervised in the new type. Getting this wrong has real operational and legal consequences: flying revenue trips, acting as PIC, or logging time as if SOE requirements were satisfied when they were not could expose both the pilot and the operator to certificate action, insurance complications, and FAA enforcement scrutiny during a ramp check or accident investigation. Chief pilots, training departments, and Directors of Operations at Part 135 and 91K operators bear direct responsibility for correctly tracking these requirements across a mixed fleet, and ambiguity in how line pilots interpret 61.64 can create compliance gaps that surface only after an incident.
The thread also reflects a broader and persistent challenge in aviation regulation: FARs like 61.64 are often summarized through pilot lore and informal training-department shorthand ("once you have SOE cleared, you're clear for life on jets") rather than through careful parsing of the actual category/class/type distinctions written into the rule. This is especially relevant as more pilots move fluidly between turbine categories early in their careers — flight departments increasingly hire pilots with mixed light-jet and turboprop backgrounds, and charter operators often maintain both King Air and Citation lines under one certificate. The regulatory subtlety between "jet type to jet type" and "jet type to turboprop type" transitions is not academic; it directly affects minimum training footprints, staffing timelines when a new type rating is added to a company's fleet, and how training departments structure IOE (Initial Operating Experience) programs to satisfy both 61.64 and any operator-specific OpSpecs A005/A029 requirements.
Ultimately, this kind of question is best resolved not through crowd-sourced regulatory interpretation but through a formal call to the FAA's Flight Standards District Office or, more practically, verification with the operator's training department and POI (Principal Operations Inspector), since SOE determinations affect OpSpecs compliance and can vary based on how a specific 135 or 91K certificate holder's training program is approved. The thread is a useful reminder that pilots transitioning across category/class lines — jet to turboprop or vice versa — should not assume regulatory shorthand applies uniformly, and should confirm SOE applicability in writing before logging PIC or SIC time in a new type rating under revenue operations.