07/09/2016
Do You Even Trim Bro!
My fellow Multi Engine instructors (and future Multi engine instructors) as well as multi engine rated pilots:
I need your input on the following safety related matter, because apparently, the way we were taught and used to teach single engine operations is all wrong (ok I’m exaggerating a bit)! Lol
In the following paragraph(s), I will be talking about single engine operations in terms of Aircraft Control and Brain Power available (I’ll elaborate on this shortly) only.
Early beginnings: During my first orientation to the cockpit of the piper Seneca, I was shown the main differences in flight controls between that and the Cessna Skyhawk which I had just come from. One of the obvious new controls to me was the Rudder trim, which as I had figured out for myself, and as my instructor had told me, is used during single engine operations, but the term used was “ extended single engine operations” and also to counteract any yawing tendencies, which was rarely the case with the Seneca which had counter rotating props(Although N767PE had a bad governor on the right engine and often had a higher pitch angle than the left prop on the left engine, even with both prop levers at max, and that resulted in pronounced right yawing tendency at times so a bit of rudder trim in the right direction came in handy)
During my first single engine exercise, I went for the immediate checklist (Control 105mph, Power Mixture Prop Thr.. Performance flaps up gear up) then as I went to grab the rudder trim, my hand was blocked by my instructor, who said that I had to muscle it, just like everyone else, or assume that the rudder trim is Broken. My initial multi engine instructor was as you’d say “cool as hell”, It’s just what he had learnt from his previous instructor, and that’s what I ended up teaching myself. Clearly this is a perfect example to the case of the 5 monkeys and the banana that FAA DPE Diego Alfonso always spoke about during his seminars.
What’s wrong with not using the rudder trim. Well, sure it was quite easy to muscle through the exercise in the piper Seneca with a light application of opposite rudder, not as easy on the DA42, either way, both aren’t safe and result in negative training! During a simulated engine failure after takeoff, Once the pilot has controlled his/her airplane with proper application of both rudder and yoke deflection, the pilot has now effectively occupied over 70%(this is mere speculation) of his/her brain power, perhaps even more when confronted with a real emergency, assuming the pilot survives the initial few seconds of an engine failure, this now leaves a smaller percentage of brain power that has to troubleshoot, plan, execute, communicate and analyze, as well as stay out of trouble in general, all while applying up to 150 lbs of rudder pressure and up to 90 lbs(got this from a test report, if my memory serves me right) of yoke/aileron deflection pressure in some cases in an UN-Trimmed airplane. Now all this is a recipe for trouble, which is why pilots joke that in a multi engine airplane, when one engine fails, you still have a second engine to take you to the crash scene, this has all too many times proven to be true, mostly with experienced (for reasons not discussed here)..
Now, on the other hand, if as the pilot starts controlling his airplane in the previously said scenario, and takes the time to properly trim his airplane to fly both hands and feet off the controls(Although you should always guard the yoke and rudder pedals), now the airplane can perfectly fly itself, it is less likely to betray you(I’ll explain this in the last paragraph, I promise, almost done here lol) and it has occupied less than 50% of your brain power, leaving a higher percentage than before to make sure you don’t end up in a crash scene, and if you are flying in an airplane that has good single engine climb performance, you can squeeze lemonades while confidently dealing with the simulated/ actual engine failure, or do one of those bob hoover rolls into the dead engine with confidence( seriously, you’ll die if you try this).
A trimmed airplane will be less of a struggle to control and less likely to betray you, meaning that when your attention is momentarily taken away from your airspeed or attitude indicator, you’ll be confident to know that your airplane won’t put you in a spin! What usually happens otherwise is as the pilot is fighting the airplane to establish the proper airspeed(VYSE in a climb), then moves on to set the power to max, more power=more yaw=more rudder pressure required= more wasted brain power, then moves on to retract the gears, the transitioning phase of the gear creates even more drag than with the gear down(I don’t have scientific proof)= decay of airspeed momentarily= rudder is less effective= more yaw= more right rudder required= more brain power lost, then the pilot reaches for the flaps to retract them(unless if VMC for that plane was certified with a certain flap setting), as the flaps retract= center of pressure(lift) shifts= nose up moment is felt= speed decays…………= less brain power available.
