The calculation of flight loads is a critical part of air vehicle design. The structural design can only occur once the representative loads are provided to the designer. On the other hand, the prediction of accurate loads is a sophisticated and complex process that requires skilled and experienced engineers. They must integrate results from wind tunnel tests, computer simulations, historical data and empirical formulations into a number of loads cases that provide a realistic assessment of the flight vehicle’s environment. Under these conditions, the vehicle must satisfy requirements imposed by regulatory agencies as part of the vehicle certification process.

Given the complexity and importance of the loads calculation, it has become a truism in air vehicle design that “the loads are always late.” This means that the quantification of the loads is on the critical path in the development of a new or modified vehicle. It also implies that inaccurate initial loads that are corrected or updated after completion of the original structural design can have a serious negative effect on the overall development schedule. In the worst case, if the inaccurate loads are not detected until after the vehicle has entered flight testing, very costly redesign and retrofitting may have to occur or vehicle placards may be established to limit certain maneuvers, thus reducing operational performance.

Due to their long history of successful application development for the aerospace industry, MSC.Software has repeatedly been asked to assist in the development of an advanced flight loads calculation system. MSC.Software’s core MSC Nastran and MSC Patran products were developed to address analysis and design requirements for aerospace applications. MSC.Software first introduced an aeroelastic capability into MSC Nastran in 1974, and this has been continuously maintained and enhanced.

Starting in late 1996, MSC.Software assembled a development team dedicated to creating a system for providing timely and accurate flight loads information. This User’s Guide documents the current release of MSC FlightLoads and Dynamics.