Secret to good landings
Teaching the stabilized approach
We've all seen it happen: pilots who come in too hot or too slow. This results in sloppy landings that can bend metal and embarrass a pilot's ego.
Twenty-four percent of landing accidents occur because the pilot either lands too short or too long. Many pilots, especially students, can't land the airplane proficiently because they approach final without any consistency, gyrating up and down and side to side.
Often, the stabilized approach can correct this deficiency. The stabilized approach can be defined very simply as a constant rate of descent and a constant airspeed that is utilized on final approach until the aircraft is in a position for the flare or roundout. It requires the aircraft to be flown at a specific airspeed, power setting, and configuration.
Years ago we were taught to "fly by the numbers." That technique is still taught today, although we may change the wording somewhat. "Flying by the numbers" is closely related to the stabilized approach.
By teaching the stabilized approach, we stand a better chance of consistently seeing good, reliable landings. We are setting benchmarks for our students so that they can monitor their approach in comparison with the ideal landing. They will be able to identify preferred times and distances from the runway. This is especially important during instrument training.
Airlines design their stabilized approach using VREF, which calculates approach speed based on weight and a correction for wind. In general aviation, FAR Part 23 determines our acceptable speed ranges. Normally if the pilot's operating handbook (POH) does not give us the appropriate information (as can happen with older aircraft), we turn to the FAA's Airplane Flying Handbook.
Acceptable speed range normally calls for 1.4 VSO on base and 1.3 VSO on final. It's a good idea to explain to the student exactly what VREF means. So many instructors simply gloss over the numbers without providing a solid explanation.
When designing the stabilized approach for your student, you can point out the many advantages:
- Predictable landing performance.
- Better situational awareness.
- Less time fidgeting with power settings.
- More time concentrating on the actual approach, especially if it's an instrument approach.
In short, the pilot who learns the stabilized approach not only will be able to devote more time to airplane control, but also will be better prepared for ensuing ratings.
But remember, the settings used for the stabilized approach are reference points only. They are not cast in stone! This point must be emphasized to the student. Different environmental conditions may cause settings to be somewhat different than the ideal settings, although the reference settings should be close enough that the student will merely need to make minor adjustments.
Let's design a stabilized approach for your student. Our first order of business is the landing checklist. We'll perform the checklist before entering the traffic pattern. By doing this, life becomes a lot easier as we set up for the landing and watch for other traffic in the pattern.
We'll fly the downwind leg no faster than the top of the flap operating range using the appropriate power setting. Have the student write down these power settings so that when entering the downwind leg the student understands that if a certain power setting is maintained, the aircraft will fly straight and level, and attention can be devoted to traffic in the pattern.
Depending upon the POH, carburetor heat may also be turned on during this leg.
Abeam the numbers, our first power reduction is applied, and our first flap setting is instituted. (Some pilots utilize their first flap setting upon entering downwind so as to keep the nose down. This is also considered good practice.) The type of aircraft will determine the utilization of flap settings. Some aircraft pitch up with a flap setting, while others pitch down. One of the main concerns at this point is to be certain the nose is slightly down so that forward visibility is improved and we are staying on the front side of the power curve.
By this time, the student should realize that a certain power setting with the aircraft in a certain configuration should provide a certain speed in level flight.
As the first power reduction is made and the airplane turns base, the speed should be slowed to 1.4 VSO with an approximate 500-foot rate of descent. Again, a certain power setting will provide this configuration. It is also here that the pilot should select the second notch of flaps, depending upon the weather and aircraft.
During each power change or flap adjustment, the student will also be taught to retrim the airplane so as to make life easier. It's amazing how many students are reluctant to "work the trim" simply because they have never been forced to use it to ease pressures on the wheel.
On final approach, we slow down the aircraft to 1.3 VSO with a constant rate of descent. By the time we are approximately one-half mile from the numbers, we should be approximately 200 feet above ground level. Full flaps can be used once we determine that the runway can be made.
For each configuration, the student should record the numbers-power setting, airspeed, and flap settings-and commit these to memory. Again, it should be emphasized that these are reference points only! Wind shear, density altitude, etc., will change these settings to some extent, but they will always fall within the reference ranges.
When the student has the proper settings in place, the airplane almost flies itself down to the glideslope at the 500-foot-per-minute rate of descent. Note: the instrument student now can concentrate for the most part on the HSI or localizer and glideslope without continually fidgeting with the power settings. With a good, safe airspeed and appropriate rate of descent, he or she merely has to ride the localizer with rudder pedals and the glideslope with the elevator, making simple, minute corrections as needed.
Utilizing the stabilized approach can certainly simplify many problems. For example, steep approaches with low power settings will almost inevitably increase the possibility of a hard landing. An excessive angle of attack could cause a stall with the risk of an ensuing spin. High angles of attack also result in poor visibility and an increased risk of collision. And excessive airspeed results in longer landing distances, as well as excessive wear on tires and brakes. If the student maintains the stabilized approach and keeps one hand on the throttle during the approach, landings become much smoother as well as safer.
But the benefit of the stabilized approach is especially evident during the teaching of the instrument approach. The student no longer has to fumble around making power and airspeed corrections, resulting in the airplane's continually getting off altitude and heading, never really holding course. With the stabilized approach, the student can concentrate on flying the glideslope to its destination.
If we teach our students the stabilized approach during primary training-and teach it so that they understand the principles behind it-all ratings thereafter become so much easier. All subsequent training will be much smoother, faster, and easier for the student because the student is allowed to concentrate on the task at hand.
Whether you prefer teaching 1.4 or 1.3 VSO, or using some flaps or no flaps during approaches, is actually up to you as the instructor, as well as the performance of the aircraft. We all have our personal favorites. Some instructors teach no flaps during approach. I favor at least one notch of flaps; I find it gives better forward visibility and tends to keep me on the front of the power curve. However, it is a matter of personal taste.
Our main concern is that we all work together and teach our students so that their transition to additional aircraft and instruction for additional ratings will go much more smoothly. They also will become safer, more knowledgeable pilots.
By Bill Cuccinello
Bill Cuccinello is a CFII with more than 5,000 hours. The Boston Flight Standards District Office twice named him FAA Safety Counselor of the Year. He is a member of the board of directors of the Aero Club of New England, the oldest aero club in the United States. He owns a Piper Turbo Arrow.