Before you read this, keep this idea in mind. This article is an advanced piece for pilots on refining their technique for obtaining the smoothest landings possible. The technique presented here is different from the one presented in the article titled, "Fanning." Fanning is about INTRODUCING a student to landings and it's done on a short term basis. Achieving The Threshold of Control presented in this article is a technique used by rated pilots to gain precise control of the landing flare. Please read both articles carefully and avoid conflating the two techniques. Thank you!
Princess Buttercup and I were walking on the Redondo Beach pier last month and unknowingly stumbled onto the “live” movie set of Big Momma 2. As I passed one of the props, an ice cream kiosk, I stopped to buy Buttercup a tasty treat.
“They’re not for sale,” whispered the clerk (unbeknown to me, an actor).
“Why not?” I said, “Princess Buttercup wants one and I live to satisfy the Buttercup’s wishes. So start scooping pal.”
“Hey, you’re trying to buy a prop on a movie set.”
Realizing what I’d done, I stayed cool. “OK,” I said, “I still want the ice cream and I’ll also take one of those big cameras while you’re at it.”
Geesh! Things are not always as they seem.
And that’s the way it was years ago when I was a very young flight instructor in the right seat of a Cessna 210, from where I witnessed a very unusual behavior. The fellow I observed doing the deed looked like he was performing miniature pushups on the yoke, moving the elevator forward and aft in small increments during the landing flare. It appeared that he was pumping himself up to get down, and he continued these shenanigans until the wheels kissed the concrete below.
Stranger than the act was the action. While doing his tiny Jack LaLanne biceps routine, and despite the forward and aft elevator movement, I hardly felt the airplane pitch up or down, nor did I feel his subsequent smooth landing. Equally remarkable was the fact that his landings were consistently smooth nearly every time I flew with him.
What was 210 Man doing here? Why would someone push and pull on the elevator control during the landing? And why would this behavior result in little or no pitch acceleration during the flare, much less a smooth touchdown? The answer lies with a concept I later came to call the threshold of immediate control.
One of the reasons pilots have difficulty making smooth landings is their failure to anticipate and compensate for ground effect during the flare. As an airplane approaches the runway surface, the wing’s downwash on the tail decreases, resulting in the nose pitching forward. The manner in which downwash affects the airplane is sometimes irregular and inconsistent, making it difficult to anticipate, much less control, the downward-pitching nose.
It’s as if the downward pitch of the nose sneaks up on a pilot and doesn’t allow much time for reaction. The result is often a series of over- and under-corrections and eventually a hard landing. If it were possible to compensate for the change in downwash by a linear increase in back pressure on the yoke, pilots would land more smoothly more consistently, because most of us routinely attempt to pull back steadily on the yoke as we flare. That’s what we were taught to do. But there’s nothing linear about elevator control forces during the flare, especially when flying larger single-engine airplanes.
There are many variables affecting the rate and degree to which the nose pitches forward in these conditions (weight, C.G., aircraft type, control surface size, and perhaps phases of the moon). To compensate for these variables (and make smoother landings as a result), 210 Man manipulated the yoke with small back and forth movements. His constant probing let him find the sweet spot where any further pull would cause the nose to rise and any less would cause it to fall. He was on the threshold of immediate control.
His technique prevented the natural forward pitching of the nose from catching him unaware. By manipulating the flight controls in this way, he knew precisely when to pull aft on the elevator and the precise amount of pressure with which to pull to maintain the desired closure rate with the runway.
To better understand this technique, here’s another way of looking at how you can apply it.
After the roundout and during the flare, apply continuous elevator back pressure, but do so in small pull-and-release motions. Think about pulling just far enough aft so that the nose would rise beyond the desired pitch if you pulled even a tiny bit more. As you begin to release a tiny bit of elevator pull, you’ll find a point where the nose would drop with any additional release of pressure. You’ve arrived at the threshold of immediate control. But the threshold is always moving, so you have to keep testing. It’s the constant recalibration resulting from this pull-release motion that allows you to make the airplane’s nose stay right where you want it to stay, and lets you retain immediate control of the airplane’s attitude. This means that the airplane’s nose shouldn’t unsuspectingly pitch downward without your being able to immediately stop its motion.
Now, you’d think the plane would be jumping up and down like one of those mechanical bulls in a Texas bar. The pull-release motions, however, are small enough (if they’re done correctly) that no one in the cockpit will feel any vertical pitch acceleration. This is especially true in heavier single-engine airplanes, where small elevator movements don’t result in the airplane’s immediate vertical acceleration. On the other hand, the lighter the airplane the more immediate will be the vertical acceleration from even small elevator movements.
By practicing with the threshold of immediate control during a few landings, you will gain a better idea of how best to flare your airplane. I’ve used this strategy successfully with students transitioning to larger machines, where the stick forces are noticeably heavier throughout the flare.
All blogs copyrighted by Rod Machado 2016