This domain has actions to embark and disembark passengers onto aircraft that can fly at two alternative speeds between locations. The STRIPS variant is rather uninteresting because the two speeds do not offer meaningful alternatives. In the metric variant the planes consume fuel at different rates according to the speed of travel (two alternatives) and distances between locations vary. Problem instances require plans to minimise some linear combination of time and fuel use.
The temporal versions are closer to the original ZENO problem. They involve durations for the different means of travel and different levels of fuel consumption. In contrast to the original ZENO problem the fuel consumption is not described by a continuous function, but by discrete step functions applied at the end points of durative actions. The fact that the fuel in an aircraft cannot be affected by multiple different concurrent actions and its value is not relevant to satisfying the precondition of any actions that could begin during the continuous consumption or replenishment of fuel means a discrete model of fuel use is sufficient, demanding less expressive power of the planners that use the model.