A couple of lessons in during a takeoff my instructor told me that it would impress my examiner down the road if instead of rolling while applying power I should instead hold the brakes to 2000 RPM, check the gauges, smoothly release the brakes, and then go to full throttle. So for the next several takeoffs that is what I began doing. I had assumed that this was to ensure that very minimum takeoff power was achieved for safety, and it also gives another chance to check the fuel and oil gauges before takeoff in case things go wrong. Of course, I’ve pondered why do this, and finally curiosity and a free minute coincided. Apparently, this practice will lower the takeoff distance by as much as 500 ft depending on the airplane. Apparently there is some debate about this practice (what a shock, right?) and some say that you can achieve the same results by performing a rolling start from the taxiway.
During one of my first introductions to single engine aviation a pilot demonstrated a short-field takeoff for me. Brakes were held until full throttle and with flaps and we leapt off the ground. So at least for short-field takeoff, when distance is precious, this practice trumps even the rolling start.
I read that the “book” take-off charts and tables were generally written with a brake-release takeoff. This got me curious so I went and found the POH for the Archer II that I’ve been learning in. Sure enough, right at the top of the chart, “FULL THROTTLE BEFORE BRAKE RELEASE.” There are no charts for the rolling start. This is a very good tip I’m going to have to remember explicitly. Pre-flight involves using these charts to ensure that there is enough runway to takeoff and this is a pretty important detail in all of that planning. If a rolling take-off is to be attempted then extra runway needs to be accounted for.
The check-list we’re using has a takeoff power of 2325 RPM. If I’m going to full power in around 3 seconds to 2700 RPM, takeoff power isn’t going to be reached until a little over two seconds in. That far in I’m already multi-tasking the rudder, staying on the center line, checking the airspeed, looking for obstacles, and waiting for 60 KIAS to lift off, and of course checking the power to reach 2325 RPM. If we start at 2000 RPM and the plane doesn’t achieve minimum climb power of 2325 then we haven’t gone very far by the time a problem so there is a lot of runway left to manage the situation. Plus we aren’t moving very fast yet.
So it seems the best practice really is to hold the brake before taking off, even if one occupies the runway a few seconds longer.
FencerPTS 