Flight duration, which consists of strip time and turning time, is an important element of flight planning of airborne surveys as it affects the cost of data acquisition. The turning time dominates over the strip time and thus dictates the flight duration. However, the current practices of flight planning assume it as a constant for easier calculations in flight planning. Further, there is no literature available explicitly on turning mechanisms for airborne surveys. Instead of assuming a constant or following the complicated models of turning, this paper advocates simple heuristic-based models and turning mechanisms. The models and turning mechanisms are developed by considering the feasibility of flight operations, experiences of pilots, and the available approximate models of turning in the literature. The paper illustrates consecutive and nonconsecutive turning mechanisms and derives comprehensive mathematical formulations to represent these. An algorithmic scheme for selection of an optimal turning mechanism is presented. The paper argues that the discussed turning mechanisms and algorithms can be combined with the strip time for arriving at the optimal flight plan using the genetic and evolutionary algorithms. The developed approach can be easily incorporated into the present knowledge base of flight planning.