One of them in the search results linked there is: Never-EVER Land - A Titan Flyer Concept. I can read the abstract, but I can not access the paper.
I understand that a flyer has access to measurements that can not be made from the surface, nor from orbit. But why would it be important for it to never ever land, or at least not land for several years?
The Saturnian moon Titan is potentially one of the most vibrant bodies in the Solar System, possessing a thick atmosphere and surface lakes of hydrocarbons and other organic chemicals, which makes it one of the biggest targets in space exploration. Traditional options to explore the moon include telescopes, orbiters, landers, and rovers, but there exists a research gap between the detail of the orbiters and land based craft. To close this gap, Oklahoma State University, proposes the Never-EVER Land, a conceptual aircraft design that would fly a long endurance mission on Titan to analyze its atmosphere and geography. The flyer’s push configuration, electronic motor-driven propellor and scientific package is powered by a Segmented Thermoelectric Modular Radioisotope Thermoelectric Generator (STEM-RTG). The polyhedral wing uses a high lift-to-drag airfoil to maximize aerodynamic efficiency. In order to fit Never-EVER Land into a launch vehicle, the flyer has a twin-boom tail configuration that allows the empennage to slide over the fuselage, and folding wings. Material choices are tentatively carbon fiber, Nomex honeycomb, and Titanium-based, with a new self-healing skin for resilience and strips of aluminum or copper to conduct heat from the STEM-RTG to the rest of the flyer. The front of the fuselage possesses an integrated communications and control unit, onboard autopilot, and ample space that can be used for instrumentation tailored for specific missions. Ventilation ports and externally mounted sensors can provide access to the atmosphere and windows can be built to provide line of sight. Given ideal conditions, Never-EVER Land is projected to fly for 2 to 3 years before gliding into a lake or flat surface on the surface of Titan. (Emphasis added)