11/08 - Bad Landings

11/08 - Bad Landings

By Steve Krog

Anyone who has flown an airplane for more than a few hours has experienced a “bad“ landing or two. And if a pilot tells you otherwise, they’re not telling the truth about other things as well. When a student begins landing practice, they will conclude that landings are a controlled crash with mother earth followed by rapid-fire mutterings from the flight instructor. But with more repetitions, landings are nothing more than another maneuver employed to conclude a good flight. And like any other exercise in life, more repetitions provide a better base for comparison and produce better results overall.

Whether a beginning student or a seasoned veteran, we as pilots all strive for a perfect landing every time we fly, but we don’t always deliver. During initial flight training, a good instructor will work with you to make consistent approaches and landings a reality. More importantly, that instructor will train you to recognize potential bad landings and teach you the proper techniques for recovery before, or at worst, during the landing. Learning AFTER the bad landing has occurred can cause problems we don’t want to talk about here. Let’s just say fixing a flying problem is easier than fixing an airplane.

There are Four Types of Bad landings

Bouncer

Porpoise

Hard Landings

Loss of Directional Control

A good landing always starts with a good approach. A good approach has two key factors: controlling your airspeed and altitude. A number of conditions can make altitude control a challenge: an unknown velocity of the wind; thermals off the end of the runway; a very heavy or very light airplane; the outside air temperature, etc. But the airspeed is something that a good pilot can always control with some precision. By doing so, you take away one of the variables that can lead to a bad landing. And keep in mind many pilots will refer to a “desired“ approach speed. There’s no such thing. An airplane doesn’t desire airspeed; it requires airspeed.

If we are too high or too fast on the approach, we’ll initially have a tendency to force the airplane onto the runway. An approach that is too low or too slow will also be cause for a potential bad landing. Let’s take a look at the different types of typical bad landings and determine what needs to be done.

Undershoot

Although the undershoot is not a landing, it does require some attention, as it is a primary cause in the development of any of the four types of bad landings. Undershoot, by definition, is not having enough altitude on final approach to reach the end of the runway while maintaining the required approach speed. The common mistakes made by many pilots when undershooting the runway is to:

Apply backpressure, raising the nose in an attempt to “stretch“ the glide to the end of the runway. This approach usually leads to the hard landing, or worse, a stall.
Apply power while maintaining a constant nose down descent attitude. While better than #1, this approach can lead to the pilot making a bouncer or porpoise landing.
Applying power and raising the nose causing the airplane to maintain approach airspeed but with increased altitude. Again, this is better than #1, but many low-time pilots will then totally chop the power when over the end of the runway. The result is a hard landing, as the airplane stalls and drops to the runway.

Bouncer Landing

Bouncer landing in a tail wheel airplane.

The bouncer landing is the result of trying to land with too much airspeed, then leveling too low, followed by jerking the control stick or yoke back. The airplane contacts the runway and bounces back into the air, at which time the inexperienced pilot will relax the control pressure allowing the airplane to contact the runway again. The pilot then applies backpressure, causing the airplane to bounce back in the air. Without the proper recovery technique, the bouncer landing will usually conclude with a hard landing when the excess airspeed is finally dissipated, and sometimes followed by loss of directional control. Experience is a great teacher, and with experience a student pilot will learn that “jerking“ any control isn’t appropriate in an airplane unless it’s doing very uncomfortable aerobatics….best left to the professionals. Do everything you can to be smooth as silk on the controls.

Bouncer landing in a tricycle gear airplane.

Should you find yourself experiencing a bouncer landing, you have three options:

1. Continue bouncing and possibly causing damage to the aircraft. This option will cause great duress for your flight instructor possibly making him or her wish they had chosen another profession.
2. Apply full power and execute a go-around. I frequently remind my students that it is safer and better to go-around and set up for another landing rather than trying to salvage a potential bad landing. I’ve had numerous Designated Flight Examiners tell me they will never fail a student on a checkride when making a go-around. But they will fail the student who tries to salvage a landing from a poor approach and landing set up.
3. If there is still enough runway —apply power, level the aircraft after the first bounce, then reduce power and re-establish the nose up flare attitude as airspeed is reduced, resulting in an acceptable landing.

Porpoise Landing

The porpoise landing is only encountered in tricycle gear aircraft. As the airplane approaches the runway with excess airspeed, a pilot will sometimes try to “force“ the airplane onto the runway by lightly pushing the control yoke forward, causing a nose low attitude. This situation occurs when students are in a hurry to get the airplane on the ground. The nose wheel makes contact with the runway, yet the airplane is still flying and the main gear wheels haven’t yet touched the runway. The first reaction most students make is to apply slight backpressure, but now the airplane is again airborne. So, they relax the backpressure allowing the nosewheel to make runway contact.

Then end result is usually expensive if the porpoise landing is allowed to continue. The nose gear will be damaged or the pilot will lose directional control causing the airplane to leave the runway and tangle with runway lights, drainage ditches or worse.

I once observed a pilot trying to land a brand new Mooney. He flew approximately one thousand feet down a 2,200-foot runway, and then forced the airplane to the runway. The nose wheel made contact but the main gear remained in the air. He continued in this attitude for the remaining length of the runway, bouncing the nosewheel until running off the end and down an embankment. The nose gear was severely damaged, as was the propeller. The owner had taken delivery of the airplane from the factory in Texas the day before and it had less than 10 hours on it when the accident occurred. His first comment was, “But I had the brakes on and it wouldn’t stop!“ It’s hard for the brakes to work when the wheels are still in the air.

In my humble opinion, should you get in a hurry and find yourself experiencing a porpoise landing, add full power and make a go around. Better to burn a bit more fuel and set up for a good landing than try to save a bad porpoise landing. It’s a lot less expensive because the nose wheel is the component most susceptible to damage on nose wheel airplanes. Do what you can to protect it!

Hard Landing

Hard landings are generally the result of trying to stretch the glide by raising the nose or when adding power, raising the nose and then chopping the power over the runway.

When trying to stretch the glide, if you actually make it to the runway you arrive at the threshold of the runway with too little airspeed (and lift) to carry through with the level off, flare and touch down. The airplane drops onto the runway with a hard thud. It may bounce slightly once due to the landing gear being exercised to its maximum followed by a second lighter thud. Rollout is usually very short as virtually all of the forward energy has been exhausted, and at worst, it may be extremely short because of one or more blown tires.

The second type of approach, coming in high and pulling the power, leads to the same result. In this configuration the airplane is 15-20 feet above the runway and already too slow when the power is chopped. Flying speed is suddenly gone, causing the airplane to drop from this height. The thud is deafening when the airplane makes contact with the runway. I’ve personally observed low-wing airplanes after a very hard landing. The gear shock struts have actually punctured the wing from the force of the landing. Not only is this embarrassing, it can be quite costly.

Should you find yourself approaching a situation for a potential hard landing, power is your friend. Application of power can salvage the landing but it does require some finesse. Keep in mind: the airplane always requires airspeed.

In the “stretch“ approach, the addition of a 150-200 RPMs will provide you with that additional airspeed while extending the approach descent. Once over the end of the runway the power must be reduced slowly while simultaneously leveling off and flaring to prevent the hard landing. As the wheels touch the runway, all power should be removed to prevent a bounce landing.

When arriving at the approach end of the runway slightly high but with some power, do not chop the power. Rather, slowly reduce the power to idle while leveling and flaring. Again, the power should be at idle as the wheels touch the runway or you’ll find yourself preventing the hard landing, but subsequently making a bounce landing.

It would be better to add full power, make a go around and set up for another approach and landing where airspeed and altitude are better managed.

Loss of Directional Control Landing

A loss of directional control landing is most often encountered in one of two situations, either when experiencing a porpoise landing in a tricycle gear airplane or when making a poor approach to land and forgetting there is a cross wind. However, it can also occur in a normal approach if you neglected to correct for the crosswind. We’ve already discussed the porpoise landing, so we’ll focus on the crosswind.

As mentioned previously, a poor approach is often the primary cause for any of the bad landings we have discussed. Add a cross wind and the chances are you may first make a bad bounce, porpoise or hard landing followed by a loss of directional control landing.

During the bounce you become so busy, or so frustrated, that you fail to remember the crosswind and its effects. While trying to recover from the bounce, the wind causes the airplane to weather vane. The nose of the airplane turns and points into the wind and the edge of the runway begins to fill your windshield. Without instant application of aileron and rudder, you may soon find yourself dodging runway lights and any other obstructions located near the runway. I once observed a student (not one of my students) experience a bounced landing followed by a loss of directional control landing. When the dust had settled, no one was injured, but three airplanes had been destroyed. The student’s airplane left the runway, ran across a 50-yard stretch of turf and collided with two airplanes tied down on the ramp.

I cannot stress enough that a poor approach followed by an attempt to salvage a landing is an excellent reason for adding full power and making a go around! In addition, a good, safe pilot always thinks ahead of the airplane. When doing so, you still may make an occasional bad landing, but we all do! But by thinking ahead, only your pride will be hurt. Your airplane will live to fly another day.

In the next issue we’ll look at all of the things needed to make perfect landings.

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