The development of Flight Control Systems (FCS) coupled with the availability of other Commercial Off-The Shelf (COTS) components is enabling the introduction of Unmanned Aircraft Systems (UAS) into the civil market. UAS have great potential to be used in a wide variety of civil applications such as environmental applications, emergency situations, surveillance tasks and more. In general, they are specially well suited for the so-called D-cube operations (Dirty, Dull or Dangerous). Current technology greatly facilitates the construction of UAS. Sophisticated flight con- trol systems also make them accessible to end users with little aeronautical expertise. How- ever, we believe that for its successful introduction into the civil market, progress needs to be made to deliver systems able to perform a wide variety of missions with minimal reconfiguration and with reduced operational costs. Most current flight plan specification mechanisms consist in a simple list of waypoints, an approach that has important limitations. This paper proposes a new specification mech- anism with semantically richer constructs that will enable the end user to specify more complex flight plans. The proposed formalism provides means for specifying iterative be- havior, conditional branching and other constructs to dynamically adapt the flight path to mission circumstances. Collaborating with the FCS, a new module on-board the UAS will be in charge of executing these plans. This research also studies how the proposed flight plan structure can be tailored to the specific needs of remote sensing. For these type of applications well structured and efficient area and perimeter scanning is mandatory. In this paper we introduce several strategies focused to optimize the scanning process for tactical or mini UAS. The paper also presents a prototype implementation of this module and the results obtained in simulations.