Descent rate at touchdown-Precision Landings

What is the best vertical speed or rate of descent at touchdown?

For me, this has for some reason been a question that was never really discussed or presented by any CFI during training.  Yet, managing a "good" landing seems to rely on getting this right.

There is a lot of discussion and writing about "when" to "flare" and/or "when" to "round-out" but there is little discussion and writing on the optimum descent rate or vertical speed when just a few feet above the runway.

Even the ideal rate of descent during the "stable approach" is a bit foggy other than the traditional 3% slope angle. 

In a light plane like a Cub, where landings often occur on short runways, generally a much higher decent angle (more like 5-10%) is desired and, because approach speeds are generally slower, the descent angle is steeper given the same vertical speed as a faster plane. In any case, the sensation of going from a steep decent rate to a shallow one as the plane approaches the runway seems more dramatic and is sometimes harder to finesse.

While "greasing" the touchdown with a zero rate of descent sounds logical and desirable, it is really not. 

The reason--attempting to achieve a zero rate at touchdown generally requires inputs starting at around 10-15 feet and an extremely low rate of descent during this last 10 feet can waste a lot of runway.  Just for example---assume that the pilot flares at the threshold from an approach descent of 500 feet per minute at 10 feet altitude and achieves a rate of decent of 60 feet per minute (1 foot per second) at 6 feet while traveling 60 miles per hour (88 feet per second). In this example, the "float" would be for six seconds or 528 feet--or more.

Boeing defines a "hard landing" as a touchdown at a vertical speed faster than 240 feet per minute or 4 feet per second and an "ideal" vertical speed of 60-180 feet per minute. (Boeing claims that they design their planes to tolerate up to 10 fps.)  My Cub (as do most light singles) seems to tolerate a 4 foot per second decent at touchdown, but "aiming" for 2-3 fps is probably ideal. 

Achieving a touchdown close to the desired spot on the runway is an important skill--especially on short runways, so in a small, light plane, a predictable touchdown point usually will require a "firm" grounding or a vertical speed of 120-180 feet per minute (2-3 feet per second.)

Since these light planes often descend at 700 feet per minute on final, the deceleration from 720 to 180 feet per minute (12 to 3 fps) must occur with accurate and precise timing.  Too soon and runway is wasted. Also, too soon or too much stick back can prolong the process, and speed falls off enough to begin a phase with an increasing sink rate. Too late may produce a hard landing, and often a bounce. The ground is approaching quickly and inexperienced pilots tend to fixate on it. (That is why it is always important to look out toward the end of the runway to reduce this "Ground Rush" sensation. )

It is often said that most bounces occur due to excess speed---too much horizontal speed or too much vertical descent rate. But, in fact, perhaps the most common cause of a bounce when landing a trail dragger is an attempt to reduce the decent rate by pulling the stick back or adding power just at or just before touchdown at a speed less than stall. (This usually is the result  of leveling out too early and can happen when attempting a wheel landing and/or a three point.)

When flaring for a three point landing, the "wasted" runway is less of an issue as speed is lost during the flare and ground roll will be shorter. But wheel landings typically occur at a  higher speed, so hitting the runway as early as possible is often important.  But, three point and/or wheel landings both require accurate timing as flaring too soon or too fast for a three point can cause a hard landing as the plane stalls high and "falls" hard to the ground. 

One of the "lessons" I have learned the hard way is that the most important time for a "stable" approach is the last 6 feet above the ground--to maintain that constant 2-3 fps descent rate. Traveling at 50 mph ground speed (73 feet per second) it takes between 150 to 220 feet to travel that last 6 feet during those 2 or three seconds. A lot can happen in those last 2 seconds.

Another reason for a descent rate greater than zero at touchdown is wind. Theoretically at a zero rate of descent, the angle of attack and airspeed is such that the wing is producing just enough lift to support the aircraft's weight.  Even a small wind gust can increase airspeed (or angle of attack) and create enough lift to cause the plane to take off and rise above the runway.    

Choosing the best rate of descent during this last 6 feet is dependent on the design of the airplane's "suspension" system and the runway surface. This includes the tires, "springs" and "dampers". The plane's suspension system will determine: A) the "G" force upon touchdown; and B) the amount of "rebound" energy that is released to induce a "bounce".  A "soft" suspension system will allow for more time for the deceleration to occur--hence less vertical "G" force deceleration.  A suspension system with little damping, can release significant energy, causing the plane to bounce back into the air.  A Cub with bungie cord suspension and fully inflated conventional tires requires a lower descent rate at touchdown than a tricked out backcountry plane with supersoft bushwheel tires and shock absorber suspension. A grass field is softer and more forgiving than a paved runway.  

Keep in mind that a plane's suspension may tolerate a harder landing with large suspension travel, but for a propeller driven plane, one must remember that the propeller is quite close to the ground, especially during a wheel landing of a plane with a large diameter prop. An especially hard wheel landing with a bit of stick forward nose down movement at touchdown could result in a prop strike. 

Finally, tricycle gear planes have a tendency to see a reduction in angle of attack upon touchdown, where trail draggers have a tendency to see an increase in angle of attack upon touchdown.  The higher the vertical rate of descent in a tail dragger, the more force is applied to dropping the tail, raising the angle of attack, and re-establishing lift at touch down.  This tendency to re-establish lift must be offset with stick forward and/or reduction on throttle immediately upon touchdown with a wheel landing, or touchdown in a three point attitude must occur as a result of a complete stall just a few inches off the ground. (Precise timing and coordination are critical to a good landing!) Below is a well executed steep descent wheel landing, almost perfectly executed.

Here is an actual Sport Cub, like mine--similarly well executed.. Followed by a short field landing by a Super Cub.

Bottom line for me in my Cub:  Short final approach with a steep angle of descent, around 50 mph indicated air speed (55 mph or 80 fps ground speed) with full flaps and vertical descent rate of 600-750 per minute (10-12 fps)---around 1100-1200 RPM or 300-400 RPM above idle.  At around 10 feet above the ground--pull (pressure) stick back (1/2 to 1 INCH) and hold to reduce descent rate to around 3 fps (average) with level or slight tail down attitude. Indicated air speed will decay and drop to around 40-45 mph (1.3 Vs with flaps) before touchdown. This process will generally take about 2.5 to 3 seconds and the plane will travel 170-220 feet, so you need to place the plane about 10 feet above the runway at 200 feet before the touchdown point.  (If obstacles are present in the approach, keep in mind that even the steep descent of 10 fps and 80 fps ground speed  (7 degree slope ) will require 700 feet to bleed off 90 feet of altitude. (Flying 100 AGL above obstacle.)  You can increase the descent rate in this case by reducing speed to 45 mph indicated (about 70 fps ground speed) and increasing descent to 12 fps (using a slip). This will cause the slope to increase to 10 degrees and will decrease the distance traveled to 520 feet during the 90 foot descent. (Keep in mind that you need to "take out" the slip at 20 feet above the ground to give yourself enough time to stabilize the plane for that stick back movement at 10 feet AGL. Taking out the slip will reduce drag allowing speed to increase and the descent rate to decrease.) 

(KTHV York happens to have a 700 foot displaced threshold on both 17 and 35, so it is ideal to practice here with 100 ft AGL altitude passing over the pavement edge and landing on the white line in front of the "numbers" using a slow steep 12 fps 10 degree descent, or pass over the runway at 75 ft AGL with a 10 fps 7 degree descent   Perhaps the reason plane performance data is often given to clear a 50 foot obstacle is because most large trees are about 50 feet tall--but to be safe, until I know for sure based on close observation or printed obstacle data, I assume I need to fly at least 100 ft AGL above most trees and wooden telephone poles on approach. Also be aware that since the typical descent rate for these landing is steeper than normal IFR approaches, the PAPI lights will remain white for most of the descent. )

Keep your eyes focused down the runway and be ready to immediately cut power and push stick forward (release pressure) to kill lift at touchdown. (Also move stick increasingly toward cross wind direction as speed is reduced.) Keep feet moving to maintain directional control. Keep stick forward until the tail begins to fall, and then pull stick fully back--keeping cross wind stick position in place during the entire ground roll. (Taking cross wind stick correction out too soon will allow wing to lift---if there is not enough rudder, a ground loop will result--if there IS enough rudder, the plane will skid sideways away from the wind. In some cases, if you apply too much opposite (downwind) rudder, the plane will steer away from rather than into the wind, causing you then to apply upwind rudder which can cause the upwind wing to fall---keep the cross wind aileron in and apply "just right" rudder--keeping in mind that the rudder often needs to move back and forth to stabilize the tail position--holding the rudder in one position too long often causes overcontrol and excess tail and wing wagging. 

Here are two videos with good approach, a bit early to level off and either adding power or pulling stick back too close to the ground--resulting in a bounce.  The first time, I go around--in the second one, I "recover" by tolerating a less elegant recovery by hopping three times while making a couple mistakes with the rudder. The good news is that I noticed my mistakes and took corrective action despite being a bit "behind" the plane.  But practice makes perfect and learning from mistakes can be productive.

Then, here I execute a nice landing on a grass strip.

My mistakes so far have been that I tried to reduce the descent rate just as I was approaching touchdown by either adding throttle or pulling stick back. The result was increased lift, in combination with the "bounce" energy released by the suspension, causing me to take off and rise from the runway--in other words, a bounce with the response then being a go around or a somewhat dangerous "bounce recovery".  You must be sure the plane is in " stable touchdown attitude/speed = descending 2-3 fps" the last 12-18 inches of descent and be ready to reduce throttle and push stick forward IMMEDIATELY at the time of touchdown. (If you are moving the stick back or adding throttle at the time of touchdown, your reaction time is not fast enough to reduce lift and overcome the energy released from the suspension.)

The tricky part of this process is the ability of identifying the site picture at 10-12 feet above the ground.  This takes practice and sometimes low passes above the runway can help.  The other tricky part is accurately controlling the air speed. Too fast and instead of slowing the descent rate, you can stop it and float.  Too slow (often because the stick is pulled back too early) and you will see the descent rate accelerate (sink rate increase) close to the ground which will tempt you to add power or stick just as you touchdown.  Most pilots are a bit "ground shy" and pull the stick back at 15-20 feet above the runway--practice and focusing eyes more down the runway will cure this bad tendency. 

Below is one of the best advisories in how to time the flare. It is taken from https://www.av8n.com/how/htm/landing.html

12.6.4  Timing the Flare

How do you recognize when it is time to begin the flare?

Let us begin by mentioning a few unhelpful answers to this question.

1. You could wait until you see the hair on the instructor’s neck stand on end, then begin the flare. This is not good preparation for flying solo.
2. Many books suggest beginning the flare at about the height of a typical hangar. This doesn’t work very well if you visit some place that has bigger hangars, smaller hangars, or no hangars at all. It also isn’t very reliable at night.
3. Some people like to flare at about half the height of a typical tree. Alas, trees work even worse than hangars, for similar reasons.
4. You could wait until the width of the runway subtends a certain angle in your field of vision. This will get you into trouble if you visit some place with a wider or narrower runway.
5. You might think of using the perception of the ground rushing past, which does depend on height. Alas, this is hard to perceive, and is unacceptably sensitive to the amount of headwind.
6. You could try to use the depth perception that comes from having two eyes. However, human binocular stereopsis is absolutely useless at distances of 20 feet or greater. By the time this depth perception comes into play, it’s too late. Wiley Post was blind in one eye, but that didn’t prevent him from making good landings.
7. 
   

Here is something that actually helps: Use your sense of timing. At each moment on short final, ask yourself how much time t remains until you would, at the current rate, reach zero AGL. When this time t reaches the special value t_F (about two seconds), start your flare. (The exact value of t_F will depend on what sort of airplane you’re flying, and other factors.)

Of course the actual flare will take longer than t_F — roughly twice as long. That’s because t_F refers to what would happen if you forgot to flare. During the actual flare, your descent rate is reduced, so you take longer to descend.

This timing technique has some nice properties. It works on wide and narrow runways both. It works during daytime and nighttime both. It causes you to flare at a greater-than-usual height if you have a greater-than-usual vertical speed.

Now all you need is some way to perceive how much time t remains. You don’t need to know the height in feet or the descent rate in feet per second; all you need is some quantity that perceptibly changes as you approach zero AGL. Figure 12.15 shows one such quantity. The left side of the figure is what you should see when you are on final, at a definitely nonzero height. The letters ABCD and WXYZ represent landmarks along the side of the runway. In particular, for night landings you would use the runway lights as landmarks.

Figure 12.15: Perceiving Zero Height

I have found that this use of runway edge light fixtures (or other references along the side of runway) and "horizon" or end of runway references--a combination of peripheral and far vision is the most helpful aid. (Most edge lights are spaced 200 feet apart.) It is all about the "sight picture" and works just as well on a grass runway as it does on a paved runway having lots of white painted lines and reference marks. With practice, the correct sight picture will be recognized instinctively.

To understand the importance of correct timing, one must appreciate that you are "managing energy" in the form of vertical and horizontal speed and you must also understand the basic "Polar Curve" that applies to the lift/drag characteristics of a particular plane.  Best Glide will produce the optimum distance traveled; Minimum Sink is a bit slower with less sink rate. Stall Speed is when any decrease in speed results in maximum sink rate.

(See below)  

Polar Curves are commonly referred to in reference to gliders.  And, when you are landing the plane, essentially you are a glider!

Generally the speed during the final few feet of descent is below Minimum Sink and since speed will decay during the final phase of flight during those last 10 feet, the sink rate tends to increase as the speed decreases. (Due to drag.) If you pull the stick back too soon (like at 15-20 feet above the runway) there is more time to lose speed and the pilot will notice and feel an increase in sink rate, even though speed is still higher than stall. Generally, most pilots feel that the best action to take if you start "falling down" the left side of the Polar Curve is to add a slight amount of power to increase speed without changing the angle of attack by moving the stick. And, if you catch yourself pulling too early, it is possible to correct the error by pushing the stick forward momentarily (briefly) to slightly increase speed and wing efficiency.  Best Glide for my Cub with Full Flaps is 49 mph; Stall is 32 mph. Minimum Sink is not published in the POH, but I have guessed that it is around 45 mph. You will note from the videos that when my indicated speed fell below 40-42 mph, I saw an increased sink rate and tried to arrest it by pulling the stick back causing a bounce. In my "good" landings, I touch down before my speed falls below that 40-42 mph. So the optimum wheel landing touch down speed  for my Cub with full flaps is probably about 42 mph. (Keep in mind these speeds are for a level or tail low wheel landing---speeds and inputs are different for a three point. (Touchdown speed for a three point would be the 32 mph stall.) Also keep in mind that all of my comments apply to a full flap approach--speeds would be higher with no flaps..for example, Best Glide with no flaps is 68 mph, so with no flaps speeds would be 10-15 mph faster and the descent slope would be less steep. ) 

Some CFI's will teach using the flaps (removing them) to change the rate of vertical descent near the ground. Essentially this changes the Polar Curve-shifting it to the right, effectively increasing the sink rate.  I find changing the flaps during this critical space to be too distracting and I would only consider this strategy if dealing with a very gusty wind condition.

I am a big fan of Boldmethod training. https://www.boldmethod.com/  I get a daily email from them and find the info very helpful.  They illustrate how to judge when you are about 10-12 feet above the runway--using a long known and accepted method of watching the growth rate of the apparent runway width. The video illustrates.  I encourage you to click in the link to their website to read the entire article.

https://www.boldmethod.com/learn-to-fly/maneuvers/how-to-perfectly-time-your-flare-and-touchdown/

One does not need to always fly the 7-10 degree slope approach in a Cub (especially on long runways) but it easier to stay proficient if you reduce the number of options that you practice and use. That is also the reason why I practice level or "slow" tail low wheel landings and seldom execute a true three point.  The other reason I prefer landing with the tail up a bit is that is seems easier when in a cross wind, and in my flying area, it seems there is almost always a cross wind!  

If I wanted to emphasize three point landings, I probably would land without flaps and would end up touching down at 40-42 mph, or about the same speed I am landing on two wheels with full flaps. It is good to land slow--the less energy at touchdown, the better, but at speeds below 40 mph, I tend to notice that my ailerons and rudder are much less effective, so for me, the 40-42 mph is the most comfortable. 

Taildragger pilots have this ongoing "argument" about the best landing being "Three Point" or "Wheel Landing". What finally made up my mind of which "side" to pick was watching landings of one of the most popular taildraggers ever, the DC-3. Here are two beautiful wheel landings--one of them very short:

And, if anyone ever claims that you can't land short on two wheels--watch this...

And, when you become VERY skilled, you can do THIS!!!!

And this is a pretty good "Cub" wheel landing...

Adventures in Delta Airspace

As mentioned, 30+ years ago, I spent considerable time flying over a large part of Texas, Oklahoma and Louisiana. In addition to earning my Private Pilot's License, I also owned a high performance airplane.  So, I have flown into several "controlled airfield" airports.  Class D: Waco, TX (KACT), Ardmore, OK (KADM), and a very busy Wichita Falls, TX (KSPS) with 617 daily operations. I have flown into two Class C: Amarillo, TX and Baton Rouge, LA. And, I have flown once thru the incredibly busy Dallas-Fort Worth space. So, I was not completely unfamiliar with airspace radio protocols when I started flying again in 2018 as a "Rusty Pilot".

But, things have changed a bit, so I did in 2018 take several hours of instruction in a Cub in Jacksonville, FL, flying out of the very busy Jacksonville Executive (Craig) Airport (KCRG) that lists having 435 daily operations.  I found the busy airspace a bit distracting but I was comfortable with the radio. I had one memorable experience when I was cleared to land, and a faster plane on a long direct-final approach came very close as I landed--so close that he had to execute a go around. Apparently, both he and the controller underestimated the difference in speed. 

My first flights in my Sport Cub N998SC were at KDMW (Carroll County, MD) that does not have a tower. It has left traffic on runway 16 and right traffic on runway 34.  My biggest concern here was that many pilots did not pay attention to changes in wind direction, so there was quite a bit of flying on both runways and opposite directions on downwind! Very attentive radio work, and diligent visual situational awareness was required.

I moved the plane to KTHV (York, PA) that also does not have a tower. Both KDMW and KTHV have about the same activity, around 140 operations a day. Both runways 17 and 35 have left traffic. Again, pilots would often land on 35 when 17 was the favored runway.   Once, I was taking off and noticed another plane turning final for the opposite runway without any annoucement.

York decided to demolish the old hangars, one of which I rented. So I searched for a new "home".  I decided that KLNS (Lancaster, PA) and KCXY (Capital City-Harrisburg, PA) were both good candidates even though both had control towers.  I convinced myself that the tower controllers might keep me safer than I would be at uncontrolled airports. 

I liked KLNS a lot, especially because it was surrounded by lots of cleared farm land that could be a candidate for emergency landings in case of engine failure.  KCXY, except for the Susquehanna River, does not provide many cleared unpopulated places for an emergency landing other than the airport itself.  But, KCXY is about 60% less busy than KLNS (75 vs 218 operations per day) and compared to KCRG's 435 per day, KCXY seemed like a pretty calm place.  In fact, KCXY appeared to be about half as busy as KTHV. 

In preparation of my first flight to KCXY, I undertook an intense self-study program. I studied the 80 page "VFR Communications-A Pilot Friendly Manual" published by Pilot Workshops. I listened to "LiveATC.com" and watched many YouTube videos published by various CFI's. I even visited the tower at KCXY and asked lots of questions.(I perhaps gave them the wrong impression. While being a "rusty and old" pilot, I think they underestimated my experience, knowledge base and requirement to always fly with an abundance of caution.) Finally, I read as many posts as I could find in pilot forums on Class D, TRSA communications.  

So I felt both prepared and nervous as I flew from York and annouced my arrival just outside Class D airspace on the radio including the suggested "negative TRSA" description. (I was not reporting to Harrisburg Approach which is the procedure for optional non-use of the Harrisburg TRSA.) 

Below is a recording of my communication with Capital Ciry Tower.  

It appears that I arrived in the midst of at least three other planes, two approaching to land, and one taking off.  I was surprised that I was told to circle outside of Class D airspace for quite awhile. Finally, I was cleared to approach the left downwind leg for runway 30. The controller commented that I was only flying 60 knots. She seemed surprised. (I was flying in the 75-80 mph range which is 65-69 knots.)  When "in sight" the controller gave me clearance to land. It did seem like a long time after I was cleared to land before I decided to turn on the left base. I "turn base" quite "early" with my Cub--it has a very steep glide and I keep close to the runway on downwind so that I can always glide to the runway in the event of an engine failure. The radio was and had been quiet,  and I was concerned that my "early" turn might be unexpected, so I announced my action. I was immediately corrected for making an "unnecessary communication", and again reminded after landing. Essentially, she told me "you don't have to report what you are doing, just do what we tell you". 

My plan for "orientation" was to follow, on another day, with pattern work, otherwide known as "closed traffic" in ATC phraseology.  So, a few days later, I did just that.  This required me to taxi from my hangar, accross one runway and down another taxiway to the the departure area for runway 30.  Everything that I read told me to use Tower frequency for communications on the runway and in the air and Ground frequency for communications everywhere else in the "movement area" of the airport.  I was also aware that some airports when not busy have only one controller for both. So I was not surprised to hear the same voice on both frequencies, but a bit surprised that it seemed at least that I was being asked for information while on Ground that I expected to give to the Tower and was receiving information from Tower that I expected from Ground.  (Part of the difference here is that Ground also serves as "Clearance Delivery" for the TRSA.  I should have announced "ready to taxi with Information Uniform, negative TRSA, runway 30 for closed traffic". And, I should have realized that the tower controller not only gave me clearance to exit at charlie, but also to proceed to my hangar.)

I felt pretty comfortable with the closed traffic activity except a bit of concern when I was told to report on downwind but was given clearance for a "touch and go" before I reported even though I intended to "land" i.e. to exit the runway after landing, coming to a full stop on a taxiway.  So I made that annoucement.  In addition, the controller warned me that I was below the published 1500 MSL "pattern altitude" on entering downwind. And, I was more than a bit concerned about wake turbulence from the Citation jet that took off before me on runwat 26, upwind and crossing runway 30. 

I really want to "do things right". That is why I visited the tower, asking many questions before flying. The controller that day was particularly impressive in his communication clarity, so I called the tower, spoke to him and asked for "constructive" feedback. He hesitated, asking if I could handle criticism and he then honestly shared his opinion by stating "You talk too much". He mentioned that he knew I had "not flown into a controlled airport for 30 years". (He did not mention that I had experience flying with a CFI recently at a very busy Class D airport--a fact that I had specifically shared during my tower visit.) He also, again was critical regarding my choice to make my crosswind turn at 600 AGL, entering downwind below the published 1150 AGL (1500 MSL) altitude. I had planned to do three closed traffic take off and landings, but his comments, in combination with comments from the controller on my earlier arrival flight, all of which I took very seriously as "constructive and well intentioned" caused me to decide to go home and "reflect and study" a bit.

Here is a recording of my communication with Capital Ciry Tower that day: 

There are two issues for evaluation.  First, radio communication with ATC is intended to enhance the safety of pilots and the public. I am sure that working the tower can be stressful when busy. So safety is best served when communication is necessary, adequate but efficient.  But, each person's judgement regarding what is necessary, adequate and efficient is probably different.  Second, the importance of flying the published traffic pattern altitude at an airport with an operating control tower seems subect to some interpretation and good judgement. 

My "reflect and study" that followed, included an intense review of two important publications: The 700+ page Aeronautical Information Manual (AIM) and the 700+ page ATC "Bible" aka FAA Order 7110.65W Air Traffic Control.  I recommend that pilots download the pdf versions on a PC and then using Adobe Acrobat, you can search for information on any "term" word or word combination. 

Link to the AIM

Link to ATC "Bible"

One thing that is especially important: § 91.123 Compliance with ATC clearances and instructions. "(b) Except in an emergency, no person may operate an aircraft contrary to an ATC instruction in an area in which air traffic control is exercised. "

While much of the information in the AIM is a recommendation rather than a strict rule, while a Pilot is "in command", while in controlled airspace, the ATC controller is "in control". 

There is no regulation prohibiting pilot communication that he/she judges is legitimately helpful to enhance safety and/or efficiency. Talking "too much" may be better than "too little" especially if the pilot is unsure that he/she is complying with controller's instructions OR, if he/she sincerely believes that the pilot's action may be unexpected by the controller and other traffic. (As is mentioned in Section 3 of the AIM Unexpected Maneuvers in the Airport Traffic Pattern  and as mentioned in 14 CFR 91.113 regarding right of way. In addition, technically speaking, the tower is not required to provide separation service for VFR traffic in Class D space. It is the VFR pilot's responsibility to maintain separation--which is why in an "abundance of caution" I felt that announcing "turning base" as acceptable and prudent-whether this was common practice or not.) Remember my experience in Jacksonville---I think if I had "annouced" when I was turning base or final, that the faster plane would have been "alerted" and might not have been surprised by how close he was to me. Even when being observed by the tower, other planes nearby are looking and listening and processing information to maintain situational awareness.  On the other hand, if the controller chides you for talking too much--pay attention and modify your future behavior accordingly. And, if the tower tells you it is OK to taxi to your hangar and you do not need to cross any runway to do so, then stopping and contacting the same controller on the ground frequency is not efficient--despite Section 3 of the AIM Exiting the Runway After Landing. 

The issue of Traffic Pattern Altitude is quite straightforward at airports without an operating tower. Operating according to the "normal" and recommended practice--at the published Traffic Pattern Altitude is VERY IMPORTANT for safety.  This includes the AIM instruction: "If remaining in the traffic pattern, commence turn to crosswind leg beyond the departure end of the runway within 300 feet of pattern altitude." and "Maintain pattern altitude until abeam approach end of the landing runway on downwind leg.." Other pilots need to know you will be where they expect you to be when you announce your turns.

The issue of Traffic Pattern Altitude at a controlled airport can be a bit different. Pilots are under control of the tower as far as their position, and the controller will provide clearances so as to reasonably assure safe separation. 

The other specification of traffic pattern is the size. In  other words, how far away from the runway is the pattern to be flown. There is no regulation regarding this other than in the AIM it states that you are to "Complete turn to final at least 1/4 mile from the runway." Fast planes require a large turning radius and "bigger" pattern.  Planes with high glide ratios can fly "bigger" patterns and still reach the airport in an emergency engine out landing. Slower planes, with high drag, like the Cub have a low glide ratio and need to fly a "smaller" or "tighter" pattern to insure they are able to reach the airport in an emergency engine out landing. 

The pictures above show the area around Capital City KCXY.  The red line in the first picture shows the "fast, high glide ratio plane" pattern.  The white line shows the "slow, low glide ratio plan" pattern--or at least how I would prefer to fly at KCXY.  The white line path avoids flying over residential/developed areas and is close enough that one can always "make the field" in an emergency.  It calls for an "early " turn to downwind, at an altitude much lower than 300 feet below the 1500 MSL TPA. It continues the climb to TPA in the downwind leg. It flys the downwind along the PA Turnpike--where the ground is the same as the airport elevation--FAR away (more than a mile) from the towers on the hill.  The "early" turn to base provides a safe margin to reduce/eliminate risk of collision with the buildings below while still being more than 1/4 mile from the runway when turning to final.   (I also made my early turn in an attempt to minimize my exposure to wake turbulence from the Citation jet that took off before me on the crossing upwind 26 runway.)

Another issue is that an emergency landing for a tailwheel airplane in a tailwind increases the chances of a ground loop and possible rotation or flip to the upside down position (with probable injury to pilot and passenger) so not only getting back to the airport is a goal, but being to land into the wind at the airport is the goal as well. 

Here is another 3D View from Google Earth. My path is in green.

Click on link to Video about Pattern Size

I specifically asked if an early turn onto crosswind was acceptable to the tower during my visit there and was told that it was "at my discretion".  Yet, I was warned twice about not being at TPA entering the downwind and that the towers on the hill created a risk. I did not think that "at my discretion" required notice on the radio of my intent or motivation-especially when told that I was talking too much and that I was sure that I had more than adequate and safe ground and obstacle clearance...and that I probably would be "inside" or closer to the airport on my downwind than any other fast plane that might be approaching.   In any case, I am assuming that entering the downwind leg at 1500 MSL is an "ATC instruction" that I will comply with until told or given clearance otherwise. 

This pattern altitude issue seems to vary by airport.  At another busy towered airport, myself and a CFI were given clearance to fly a lower than "published" TPA in the interest of "efficiency" so that we could get more take off and landings in less time.  We were flying a S-LSA cub in a "tighter" pattern, closer to the airport and reaching only 500' AGL.  This is in harmony with the new TPA rules in AC 90-66B (see link below) that call for THREE Traffic Pattern Altitudes: Turbine Powered (1500 AGL); General Aviation (1000 AGL), and UltraLights (500 AGL). 

New 2018 FAA TPA Rules

This issue and experience does bring one important issue to the fore.  I fly for the pleasure of it and only with "an abundance of caution".   While flying at Class D airports is not particularly intimidating, I am not sure you could describe the experience as "fun". This is especially if one has to circle outside waiting for permission to enter the space waiting for two other planes to land ahead of me. (Perhaps the concern is a Cub is slower than many other planes and requires a different separation schema. My wait was not rediculously long, but the uncertainty of how long it would be was a bit disconcerting--another couple of turns and I would have returned to York.)

I like KCXY a lot, it is a nice airport, but strict compliance with the 1500 MSL (1160 AGL) TPA, flying past the end of the runway until I reach 860 AGL requires me to fly over heavily populated areas and reduces the probability of reaching the airport for an engine out emergency landing. It would take me 86 seconds to climb that distance at 600 fpm (more or less 10 fps or 520 fnm) and I would have traveled 7600 feet after liftoff (over Drexel Hills area and near Hillside Elementary School) before my turn to crosswind. If I ignore the 300 foot rule and abide only with the 1500 MSL on downwind, I would still need to fly to 710 AGL, 6200 feet past lift off before turning crosswind, and still over populated areas for quite some time. And, probably not able to make it back to the runway safely while in the crosswind leg and the early part of downwind. Under the right conditions (cool temperature, stronger head wind) flying a best angle of climb and maximum full throttle until turning downwind, it is possible that I could turn crosswind at less than 1000 feet past the runway, but I prefer not to push the engine that hard with high cylinder head temp followed by fast cooling in closed traffic. So, closed traffic "practice" flying at KCXY with the ATC instructed 1500 MSL (1160AGL) TPA may not fit my need for flying with an abundance of caution and care.  So, my "practice" flying will probably have to be somewhere else, limiting my flying to departures and arrivals from/to KCXY to/from other airports. (BTW--this applies to runways 30 and 26---my concern is much less if taking off from runways 12 or 8 in regards to risk of going down in a populated area. Although on runway 8, the risk of having to make an emergency landing in the river is a bit of a concern.) 

And, if arriving in Class D as the "69 knot slow cub" plane is going to mean that I wait, circling, until everyone else entering the space with a cruising speed of 90-100 knots or higher has landed, then each arrival could be quite frustrating. 

Grass Field Landings

Everybody knows the tailwheel airplane requires quite a bit of extra diligence in regards to rudder during landing.  Because the center of gravity is behind the main front wheels, during deceleration, if/when the center of gravity moves to one side, no longer in line with the center of the main wheels, the plane wants to turn and if not corrected almost immediately with rudder, the turning momentum grows and what is called a ground loop (one can think of it as a spin out) is inevitable. 

Mastering a tailwheel airplane first requires a keen sense of this "misalignment" and the development of immediate, rapid and controlled rudder response/s.  And, the pilot also must develop an ability to input a series of "follow up" rudder inputs to avoid overcontrolling the plane and causing a ground loop in the opposite direction! Some call this process of "wagging the tail" like an excited puppy.

Earning your tailwheel endorsement requires you to demonstrate competency to a CFI, generally on a relatively smooth and level runway, in relatively calm wind conditions.

Landing on a grass strip is supposed to be easier for a new tailwheel pilot, as the touchdown is more "forgiving".  I found that to be true to some extent-at least on relatively flat and smooth grass strips.

Here is a landing at Bermudian Valley Airport in East Berlin, PA.

Real world flying often requires landing on bumpy, sloping runways with gusty crosswinds. The new tailwheel pilot will quickly realize there is "more to learn". 

Convinced that practicing landings at a Class D airport was not my cup of tea, I decided to move my plane to a grass strip.  Specifically, Baublitz Airport 9W8.  100 foot wide turf runways (10/28) with about 2000 feet of usable length.  It is shaped like an "M" with a short flat surface at each end followed by a downsloping (2% grade) touchdown area with the low spot in the middle. So touchdown occurs on a downslope, and the final part of the rollout being uphill. (N998SC usually uses less than half the runway length.)

On runway 28, the area adjacent to the touchdown area is higher with a long section of hangars that shade any crosswind from the right. But, once past the hangars a right crosswind will swoop down and challenge your directional control at the most critical part of your post touchdown rollout. 

In addition, the turf is good, but it is not a golf green or fairway---it is bumpy enough to make a light plane move around, up/down quite a bit. More like a freshly mowed hay field.

The airport is surrounded by farm fields (corn and/or soybeans) on three sides.  The west end of runway 28 adjoins Muddy Creek Forks Rd. with a steep dropoff, telephone poles and wires. On the south side of the runway, there is a 300 foot area with a steep 10 foot drop off on the west portion. Every 200 feet on each side there are 2 foot tall landing lights.  Not a place where ground loops occur without penalty except if you are lucky enough to go off into a recently harvested section of farm field on the north side of runway 28. 

Here is a video of my first landing...

Before moving my plane, I took instruction from Larry Stone, a CFI (and former airline pilot) at Baublitz in his C172.  So, I knew the landing area was a bit bumpy, and concluded that landing on a downhill slope was also "tricky".

Now on my 30th "solo" landing in N998SC, and my 133rd tailwheel landing (around 20 of which were on flat grass runways) during the past year, I was feeling reasonably confident about my crosswind landing technique, but conditions for my first landing at Baublitz were to challenge my personal minimums. Wind was a 45 degree 8 mph crosswind. The crosswind component being around 4 mph, well below my 8 mph personal minimum.  Gusts however, were 15-20, so the  7-10 mph crosswind gust component was to test my skills. 

The downslope effect was as expected. I needed just a bit extra "forward stick" at touchdown in my wheel landing to keep the front wheels on the ground.  The bumpiness however was very distracting and coupled with the gusty crosswind, a lot of control inputs were needed.  I did not anticipate the increased crosswind after passing the hangars which pushed my plane to the left. 

And, most importantly, I did not remember or sufficiently appreciate the effect of gyroscopic precession when dropping the tail wheel.

Once I had rolled sufficiently far enough to have slowed below stall speed, one reaction to the gust was to get the tail wheel down on the ground. And, since the plane had just been pushed left (right aileron, left rudder for a right crosswind), I pulled the stick back fast while at the same time releasing some of that left rudder and increasing right aileron.  Surprise!  The plane's nose pointed right much faster than I expected.  In addition, instead of the tailwheel on the ground providing almost perfect steering, it was bouncing on the bumpy runway.  So I had little help from the tailwheel and with full flaps, engine at idle, and a plane now rolling maybe only 15-20 mph, very little control from air flowing past the rudder. Toe-brakes to the rescue.

During training, you "learn" and "know" many things, but sometimes it takes a bit of experience to make what you "know" a matter of instinct. 

First, I knew that "precession" caused the nose to veer left when pushing the stick forward, lifting the tail. (It is one of the four left turning tendencies requiring right rudder durring takeoff.)  I also knew that the opposite occured when dropping the tail---"precession" causes the nose to veer right.  This day however, my stick back tail down move was not accompanied by any compensating left rudder.  

When landing with a left crosswind, this issue is less important as the right turning tendency actually counters the crosswind effect.  But when landing with a right crosswind, the right turning tendency from the precession when dropping the tail adds to the weather-vaning force of the crosswind. (Most of my crosswind landing had been with a left crosswind.) Every stick movement requires a coordinated compensating rudder input.

Second, you have to remember adverse yaw when making rapid changes with ailerons. In a gusty situation, a gust from the right may require more right aileron, and the adverse yaw will point the nose to the left.

Third, I knew that full flaps created a risk that the plane could "take off" in a gust.  In this case, it did not "take off" but it did get light. It is harder to control a plane when it is bouncing on the runway and is not firmly "planted".  I should have taken out the flaps as soon as possible after touchdown. 

Fourth, crosswind control requires a steerable tailwheel firmly on the ground with traction, OR enough air flow over the rudder to allow the rudder to control direction. On a bumpy grass strip, the tailwheel may not be firmly on the ground and may not have side force traction.  And, if the plane has slowed, with the engine at idle, there may not be enough air flow over the rudder.  I should have used a bit of power to generate more airflow to improve rudder control. 

Finally---brakes are for holding the plane during runup, BUT ALSO for occasional directional control.  Be ready to use them carefully. 

Most importantly---anticipate all of the forces on your plane and react instantly and appropriately.  Don't let the bumpiness of the runway distract you from flying the plane correctly. 


No doubt, some readers will conclude, "He should have done a three point!".  The argument and preference of one group of pilots for three point vs wheel landing continues. There is no doubt that a landing with less "energy" makes the consequences of mistakes a bit less severe.  However, in a gusty cross wind situtation, on a bumpy grass runway, my preference is to wheel land and to use the rudder for directional control for as long as possible to a point where when the tail is dropped,  the plane is almost stopped. 

As usual, I am practicing this scenario high gusting right xwind on my Prepar3d Simulator. Including a lot of practice moving the flaps right after touchdown so that I will not be distracted during my real life landings. The bumpy down sloping runway however is something you have to practice in real life. 

Here is a video of my third outing a Baublitz.

Hangar Odyssey

When N998SC was first delivered to me in June 2018, the only hangar available was at Carroll County (KDMW) airport. It was a nice T-Hangar, with a concrete pad for the plane, the rest of the interior being gravel. Sliding doors.  Price: $375 per month ($4500/yr).  40 minute drive from my home. Fuel and A&P on site.

Carroll County was a good airport, but York (KTHV) was closer to my home on Lake Pahagaco, so when a T-Hangar became available there in September 2018, I moved the plane. Very old hangar (70+ years old) with a lot of rust, but servicable with a concrete floor, good electric supply. Sliding doors. Price: $307 per month (3680/yr.) 10 minute drive from my home.  Fuel and A&P on site.

York arbitrarily decided that they were going to demolish the old hangars due to excess maintenance costs. I had 3 months to leave.  I checked at Lancaster (waiting list), Carroll County (waiting list), Baublitz (waiting list), Forest Hill (waiting list) and Capital City-Harrisburg.  There was one available at Capital City (KCXY) so I took it and moved the plane there in late August. Old T-Hangar hangar (40+ years old), but servicable with an asphalt pad for the plane and gravel in the rest.  This was my first experience being based at a Class D airport with a control tower and in a ATC TRSA.  45 minute drive from my home. Price: $300/mo ($3600/yr.)

About 2 weeks later, I got a call from Baublitz (9W8). A "community" hangar for two planes was available. I had moved my residence to New Freedom (downsized to a condo), and Baublitz was less than a 30 minute drive. Plus, I always wanted to be based at a grass strip. So I moved to Baublitz. Beatiful hangar with nice concrete floor and sliding doors on a curved track. Fuel and A&P on site. Price: $265/mo ($3180/yr)

Small airport with less than 10 planes based there. In the middle of farm fields. Only challenge was the area in front of the hangar was sloped quite a bit and pulling the plane into the hangar was more than I could handle single handed. I did it once--estimated pulling effort was almost 200 pounds.

So, I engineered a solution using lines, pulleys and a winch for force multiplication, and a special bridle for the tail wheel.  

Manuevering a taildragger on level ground with a quality tow bar is pretty easy, especially for a Cub weighing less than 900 pounds. But, pulling it uphill with a required force of 200 pounds seemed to be an excessive load on the tow bar, and the tail wheel mechanism.

First, I added a caster wheel to the towbar so that it would not catch on the ground. Then I rigged up a bridle using a 31" axle strap and a 72" recovery strap.  I first tried looping the axle strap around the part of the tail wheel assembly below the pivot, but decided that looping it around the part above the pivot placed the least stress on the components. By lightly coupling the recovery strap to the tow bar handle--the handle and the straps work together with the tow bar proving "steering" and the straps carrying the pulling force. 

Using a pulley attached to the recovery strap, and anchoring one end of a line to a ground anchor; pulling on the free end of the line, I was able to get a 2X mechanical advantage--good enough for most of the movement except the transition from the steep area to the flat area near the entrance of the hangar. For the last part of the pull, I used a 1500 pound electric 110V winch.  I anchored the winch using a rubber pad and plywood weighted with 350 pounds of sand and metal ballast. 

This arrangement allowed me to pull up to the hangar sideways to avoid blowing air into the hangar if I left the doors open, and on a spot where the ground was level so I could exit the plane without setting my brakes. 

Landing on a grass strip is "different" than landing on a wide asphalt runway.  Each grass strip tends to be different in shape, slope, bumpiness, and crosswind issues. But a grass strip is what my Cub was made for, so the plane is happy! Moving has made me feel a bit like a gypsy, but each airport has provided unique and valuable learning experiences and I am a better pilot because of it.