Page 30 - Volume 14 Number 10

KA models, (B) tighten the friction knobs and (C) go back to flying the airplane with his left hand.
If the PL migration aft is not noticed, however? It sets the stage for tragedy.
Realize the following facts. First, power lever position controls the engine’s compressor speed (Ng) directly, not torque. Of course, torque and ITT are what we watch as we adjust power but the reason they change is because we selected a new Ng speed. It’s said that about the last 50% of available power is all achieved in about the last 12% of Ng. Thus, it takes relatively little PLM to cause a major loss of power. In the case of the left PL moving nearly to idle while the right PL comes back only one-fourth of the way, we would have close to no power on the left and maybe only 50% on the right.
Second, the marvelous auto- feather system must be able to know that a loss of power is unintentional not intentional. It
are incapable of automatically feathering.
Third, the +10-degree pitch attitude we have been taught to hold after takeoff (the 350’s POH is the only one that actually states that value but it works rather well for all KA models) will not be correct with the windmilling prop and, probably, reduced power on not only the left but also, to a typically lesser extent, on the right as well. Airspeed will rapidly decay if that attitude is maintained.
Keeping the right hand on the power levers obviously eliminates the possibility of PLM. I am so used to doing this in piston-twins as well as King Airs, personally I do not reposition my hand when Decision Speed is reached even in the 350. Don’t get me wrong: I am not saying that I’d pull power back and abort above V1 in a 350, but the hand stays on the PLs. I have no argument whatsoever with those 350 pilots who do move their hand to the wheel at V1.
But folks, I beg you ... always prevent Power Lever Migration! How? First, by snugging up those friction knobs! How do you know they’re set properly in a King Air that is new to you? One way is to lift your hand just slightly above the PLs after you have set takeoff power. Did anything move? No? Then put your hand back down and continue. Did a lever start to retard? Depending on the length of the runway, either pull both back to idle and taxi back for another try, now with tighter
21 achieves this knowledge by looking 11 at PL position. If the PL is moved
25
back, the autofeather “thinks” that the resultant power reduction was requested by the pilot and feathering the propeller would not be appropriate. But if the PL is still well-advanced yet little power is being produced ... something’s wrong and autofeather will ride to the rescue and feather the propeller to reduce the drag. Therefore, when PLM occurs, autofeather is rendered inoperative. In fact, if either PL is retarded both propellers
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28 • KING AIR MAGAZINE
OCTOBER 2020