SEEING RED? Engineers tested the limits so you don't have to BY WILLIAM E. DUBOIS T he redline on the airspeed indictor is the ultimate stoplight. But it's not the only red in the cockpit. The tachometer has a redline. So, too, do the cylinder head and oil temperature gauges. Oil pressure gauges have two: one at the top and one at the bottom. How are these redlines determined, and who chooses the numbers? Like Scotty on Star Trek, can you exploit some...you know... wiggle room to the numbers and push performance just a little further? What really happens if you go into the red? 48 FLIGHT TRAINING DECEMBER 2019