THINGS ARE NOT ALWAYS AS THEY SEEM ....
Acknowledgements: Rod Machado
(Ed. Note: An interesting technique for anyone experiencing difficulty in touching down gently)
“When I was a very young flight instructor in the right seat of a Cessna 210, I witnessed a very unusual behaviour. The fellow I observed looked like he was performing miniature push-ups 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 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 behaviour 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 round-out 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.
The proper application of this technique requires proportionally smaller forward and aft yoke movements to remain in the threshold of immediate control when flying airplanes in the weight class of a Cessna 150 or J-3 Cub.
Despite the lack of pitch acceleration, you’ll still see the controls moving forward and aft during the flare. That’s what propelled my eyebrows when observing 210 Man many years ago. This movement doesn’t matter as long as the airplane isn’t pitching up and down and annoying anyone on board. Remember, there are many ways to fly an airplane, and this is just one technique to help some pilots make smoother landings.
Over the years, I’ve observed this technique being used by pilots who I suspect had experienced a decline in their kinetic, visual or tactile sense (perhaps because they counted sunspots for recreation and/or manicured their fingernails with power tools). It took me a while to realize that what they were really doing was amplifying their sense of elevator response. In this way, they were seldom surprised by a sudden change in attitude because they were continuously making micro control adjustments on the yoke and thus compensating for the tail’s aerodynamic surrender as it neared the runway.
As an aside, this pull-release technique is often used by pilots making extreme short field landings. Pilots operate deep in the region of reversed command during these landings. Slight forward and aft movement on the elevator lets them know how much (if any) aft elevator travel is still available, as well as how effective the elevator response is at that instant. The moment the elevator hits the stops, the pilots knows he’s reached the limit of the pitch envelope and must now compensate with a change of power or forward pitch.
By practising 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.
Ideally, you should apply one continuous increasing pull on the elevator during landing. As you get to know your airplane by using the pull-release technique, you’ll be in a better position to approach the ideal.
Or not. Some people have a difficult time making landings any way other than pull-release. So be it. While it may look a bit strange to a close observer or new flight instructor, at least they’ll land as softly as a butterfly with sore feet".