Abstract:
In the realm of transitioning eVTOL aircraft, hindrance may be placed on performance in each of the two flight modes due to the existence of apparatuses or devices intended wholly for the other mode. For example, the presence of wings will normally reduce hover endurance due to their weight, and the use of a plurality of exposed lift-propellers - for hover stability and control - can lower flight speed and range in airplane mode because of the excess drag. It would seem, then, that transitioning eVTOL aircraft are generally poor performers in any mode when compared to their dedicated, single-mode cousins. This paper explores another possibility, of substantial performance improvement when the devices or their use become elements augmenting performance in the other mode - or cross-modally. Through an example dual-propeller aircraft, several cross-modal elements - including phenomena like the fan-in-wing effect and the inverse of Custer's channel-wing effect - are identified and their merits expounded.