A pilot holding a Commercial Multi-Engine Land (CMEL) certificate poses a logging question that cuts to the heart of FAR 61.51's second-in-command (SIC) logging provisions. The scenario: a CMEL-rated pilot is riding right seat in an Embraer Phenom 100 (EMB-500) alongside a fully qualified, unrestricted PIC who holds a CFI certificate but is not an MEI, operating under Part 91. The poster correctly suspects the answer is unfavorable — under 61.51(f), SIC time may only be logged when the aircraft is type-certificated for more than one required pilot, or when operating under an operations specification requiring a second-in-command. Since the EMB-500 is certificated for single-pilot operation and the flight is conducted under Part 91 (not 91K fractional ownership or Part 135, which often carry SIC requirements via authorization or insurance mandates), there is no regulatory basis for logging SIC time regardless of the right-seat occupant's qualifications. The CFI status of the PIC is a red herring here: instructional logging authority under 61.51(g) requires the instructor to be giving instruction and the recipient to log it as dual received, but that pathway requires the instruction actually be given and documented as such — not simply "learning by observation" while occupying the right seat during revenue or personal transportation flights.
This question surfaces constantly among pilots building time toward ATP minimums or transitioning into turbine/jet types, particularly in the growing market of owner-flown or single-pilot Part 91 jets like the Phenom 100, Citation Mustang, and similar entry-level VLJs. Many low-time commercial pilots seek "jump seat" or observation opportunities with type-rated owner-pilots specifically to gain exposure to turbine systems, glass cockpits, and jet operating environments before pursuing a type rating or SIC-qualifying job. The hard reality is that mere presence in the right seat — even actively assisting with checklists, radios, or systems management — does not generate loggable flight time unless one of the narrow 61.51(f) exceptions applies. This is a frequent source of confusion because pilots conflate "operational usefulness" or "manipulation of controls" with logging eligibility; FAA guidance and years of legal interpretations (including the well-known Mangiamele and Hollaway letters) have reinforced that sole authority to log time rests on certification requirements or type certificate data sheet crew complement, not on practical necessity or informal arrangements between pilots.
For working and aspiring professional pilots, this distinction matters significantly in an era where insurance underwriters, not just the FARs, increasingly dictate crew composition for high-performance turbine aircraft. Even when logging isn't possible, many owner-operators and insurers require a second, type-rated or experienced pilot in the right seat for risk-mitigation purposes — creating scenarios exactly like this one, where valuable cockpit experience exists but no compliant logbook entry can capture it. Pilots in this position sometimes pursue an MEI or additional instructor credentials specifically so that the arrangement can be restructured as bona fide dual instruction, converting otherwise unloggable observation time into legitimate dual-given/dual-received entries. This underscores a broader trend in general and business aviation: as single-pilot-certificated jets proliferate in private ownership, and as low-time commercial pilots seek non-traditional pathways into turbine flying, the gap between operationally valuable experience and FAA-loggable time is becoming a more prominent friction point — one that flight schools, mentorship programs, and career-track pilots need to navigate carefully to avoid logbook entries that could later draw scrutiny during airline or 135 background checks.