Experimenter is a magazine created by EAA for people who build airplanes. We will report on amateur-built aircraft as well as ultralights and other light aircraft.
Issue link: http://experimenter.epubxp.com/i/96284
F li g h t Te s t in g Te c hn i q u e s Airspeed Calibration Flying the ground course By Ed Kolano Last month we talked about selecting your ground course for your airspeed calibration test flying. The ideal location is flat, clear of obstacles, and has consistent topography with options for landing off airport if something should go wrong with your airplane during a run. Now it's time to describe the test methodology. If it starts to sound too complicated or challenging, just remember, all you're really doing is flying straight and level. Do not make your first pass over the ground course during your airplane's first test flight. Preview the course the day before to become familiar with it. Survey the course from a safe altitude, say 1,500 feet AGL, making sure that you have plenty of turnaround room at both ends. Look for your checkpoints, obstacles, and other disqualifying features like wires, farm animals, etc. 42 NO. 4/ DECEMBE R 2012 Then make a run in both directions at a comfortable cruise airspeed at a lower altitude. Make a few more passes at progressively lower altitudes until you are satisfied the course is suitable and you are comfortable flying it at the low test altitude. You're not recording data here. The purpose of these runs is to become familiar with the course and comfortable flying it at low altitude. Test Day As part of your test planning, determine the correct MSL altitude that will put your plane at the desired safe AGL altitude, based on the course's known elevation and local altimeter setting. After you've established the desired test altitude, set your altimeter to 29.92 to read the pressure altitude you'll need to calculate density altitude after your test flight. Photography by Jim Koepnick