History has shown that a larger flight crew does not per se imply that aircraft operations will be safer. The goal of this thesis is to determine the technical hurdles to Single Pilot Commercial Operations (SPCO). Continued technological developments, the upsurge of commercial Unmanned Aerial Systems, the non-negligible cost of air crews, and yet, stagnation in commercial crew reductions since 1980 are reasons to clarify the current technical hurdles to SPCO. The research was initiated with a broad literature survey. It was found that advances in technology and human factors understanding have made each historical crew reduction possible, through a redistribution of tasks across (fewer) humans, automation, supporting infrastructure and accompanying procedures. An exhaustive list was then formulated of all issues that could potentially affect a reduction to SPCO. Consequently, in-depth research of each issue determined the most predominant challenges to SPCO are; a. providing the single pilot with the correct situational awareness at a manageable workload; b. ensuring adequate monitoring of pilot performance without an on-board human co-pilot; and c. ensuring redundancy in case of incapacitation. Finally, Single Pilot Incapacitation Redundancy (SPIR) solutions were explored by means of a scenario analysis and functional analysis. The greatest challenge to SPIR turns out to be the setting of the incapacitation detection sensitivity threshold; avoiding excessive false warnings (alarm problem) yet retaining immediacy for timely recovery of stable flight; both incapacitation detection and seem-less control take-over are tasks more suited to the adaptability of humans. A concept for a SPCO flight deck has been presented in which these issues become obsolete.