Andy Ross writes: > I'd *love* to see good numbers for propeller acceleration, however. > If one of the Real Pilots out there could go out with a stopwatch and > get us graphs of RPM vs. time for full throttle acceleration and > cut-power deceleration I'd be eternally grateful. :)
I don't want to get banned from the flying club (or demonstrate my limited forced-landing skills), so I'm not going to abuse the engines by jamming the throttle in hard to full from idle and timing it. Here are some unofficial observations, however, from various 172's: 1. The prop accelerates and decelerates very quickly. You're supposed to move the throttle smoothly so that the changes don't happen too quickly. 2. During runup, I push the throttle in from 1000RPM to 1700RPM -- the lag between throttle movement and tach indication is barely perceptable (under 0.25 sec). 3. Next, I pull the throttle from 1700RPM to idle. The drop on the tach from 1700RPM to about 600RPM is nearly instantaneous (again, under 0.25sec). 4. At shutdown, I set the engine to 1000RPM, then pull the mixture to shut it down. The engine continues to fire for a couple of seconds until it burns off all its fuel, but once it stops firing, the propeller stops in well under a second. During takeoff, I have other things to worry about, but I'll guess that the lag between 1000RPM and max static (2200-2400RPM) takes less than 0.5sec, possibly again less than 0.25sec. All the best, David -- David Megginson, [EMAIL PROTECTED], http://www.megginson.com/ _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
