Engineering Flight Simulator, Cessna 172 Simulation is supplied as is. Sean Wakayama disclaims all warranties, either express or implied, regarding this software, its merchantibility, or its fitness for any particular purpose. Sean Wakayama will not be liable for any special, incidental, consequential, indirect, or similar damages arising out of the use of the product, even if Sean Wakayama has been advised of the possibility of such damages. In no event shall Sean Wakayama’s liability for damages ever exceed the price paid to license the software, regardless of the form of the claim. The person using the software bears all risk as to the quality and performance of the software.
Cessna 172 Simulation is distributed as shareware. You may try it out free for 30 days. If you wish to use this software after 30 days, you must pay a $25 registration fee or purchase the full Engineering Flight Simulator program. Registered users will receive a complete manual. Complete the accompanying order form, and mail it with a check to
Engineering Flight Simulator was written to enable quick evaluation of aircraft handling qualities. In the full version, the engineer can specify general aircraft dynamic properties with easily prepared input files and thereby simulate virtually any airplane in forward flight. Cessna 172 Simulation uses a subset of the EFS code to model a single airplane. The Cessna simulation serves two purposes: it is an inexpensive way for the engineer to assess the value of the simulation before purchasing the full product and it is a source of entertainment and education for those who are interested in how an airplane behaves but have no need to model arbitrary aircraft.
Engineering Flight Simulator provides interactive, real time simulation of aircraft handling qualities, simulated by computing full 6 degree of freedom dynamics. Dynamic motion is evaluated by solving stability equations that are linearized from the full nonlinear equations at each time step. Several nonlinear qualities are modeled as follows. Aerodynamic forces and moments are determined from non-dimensional stability derivatives. Dimensional derivatives are calculated from the local density and velocity at each time step, capturing nonlinear effects such as the change in dynamic pressure with velocity. A U.S. Standard Atmosphere model is used to evaluate density as a function of altitude. Nonlinear stability changes with respect to angle of attack are handled by interpolating through stability derivatives for up to 10 angles of attack. A direction cosine kinematic model is used to permit simulating any aircraft orientation without gimbal lock. Nonlinear effects from orientation and inertial dynamics are captured by evaluating the stability equations based on the initial dynamic state at each integration step.
EFS can give real time simulation at a rate of about 5 frames per second on many Macintosh II class machines. Integration time steps can be adjusted for faster real time rates on more powerful machines, or for more accurate calculations at less than real time.
Simple control systems can be modeled with EFS. Control systems can be specified with proportional feedback on alpha, beta, p, q, r, phi, theta, and psi states, plus mixing and scaling of pilot inputs. Pilot controls for elevator and aileron are taken through mouse or joystick. Keyboard inputs are used for rudder, thrust, and other controls.
EFS has extensive flight recording capabilities. Flights may be recorded, saved, and replayed, a useful feature for demonstrations. Flight data can also be saved as text so that it may be imported to other applications such as plotting programs.
Engineering Flight Simulator was written for the Macintosh computer. Because of its numerically intensive engineering computation, EFS requires an MC68020 or better CPU, an MC68881 or better math coprocessor, and 4 megabytes of RAM. The program has been run on the following machines: II, SE/30, IIcx, IIci, and IIsi (with coprocessor card). It should also run on the following: IIvx, Centris 650 (with FPU), Centris 660av, Quadra 610 (with FPU), Quadra 650, and up.
EFS runs under Macintosh System 6 and System 7 software. EFS is compatible with the MouseStick joystick made by Advanced Gravis.
