Page 20 - July 2023

Another time that it is easy to erode the prop blades is during high- power run-ups. For example, the Overspeed Governor test requires a lot of power. Please make every effort to find and use a rather clean, paved area of the tarmac when conducting your checks.
Similarly, consider the condition of the runway as you initiate the takeoff roll. If it is unpaved or the pavement is in poor shape, now is the time to make a rolling takeoff with power application coming in proportionally as the airspeed increases. Of course, when the runway is of minimum length, we won’t have the luxury of slow power application. But when there is excess runway, it is a technique that has merit.
How about landing? How do we avoid blade erosion now when we need and want to use Reverse? Easy answer: Go in quickly and deeply, then get out.
For a landing where aggressive Reverse will be used, it is common to
run the propeller levers full forward well before touchdown so that we waste no time moving them after touchdown. All we have to do is lift and pull the power levers aft. Here is a time that aggressive, fast action is indeed called for and won’t harm a thing. Remember when I stated that Maximum Reverse is less than 50% power? Hence, there is no way that torque, ITT, not N1, is of any concern to you, the pilot, when those power levers are buried all the way back. “Slam” is a word used rarely when talking about flight and engine controls but, truly, here is the time to slam those power levers into Maximum Reverse without delay. Also realize that the power levers move in an arc, not in a straight line. To position them at Max Reverse requires more of a downward push during the last bit of travel, than an aft pull.
There are three important reasons for obtaining Max Reverse immediately. First, the sooner we can establish full reverse thrust, the
shorter our landing distance will be. Second, the drag that Reverse provides is dependent upon airspeed squared. That is, at 80 knots, the drag is four times as effective as at 40 knots. Third, we only want to utilize Reverse when we are moving forward fast enough to leave the sucked-up dirt and debris behind us.
It is maddeningly common for me to observe a pilot who uses very little Beta or Reverse after touchdown but then, when he sees the turnoff coming into view, he at last starts pulling Reverse thrust. No, no, no! Now, not only is Reverse not very effective due to the slow airspeed, but also blade erosion is almost guaranteed if the surface is less than perfect!
Sure, if you are quite familiar with the airport layout and know that the turnoff is far ahead, the use of Beta only after touchdown – and maybe not even much of that – is just fine. But when the turnoff is a bit “unknown,” it is much better to
18 • KING AIR MAGAZINE
JULY 2023