2011 09 its all in the feet

Vintage Instructor THE

BY Steve Krog, CFI

It’s all in the feet Not long ago I had a young and fairly new private pilot enroll for a tailwheel endorsement. This person, a very enthusiastic pilot, had accrued about 70 hours’ total time in the previous 18 months. After a preflight briefing, cockpit briefing, and doing some taxi Figure 7s on the ramp, it was time to move to the runway. All proceeded as expected until we positioned the airplane for takeoff. An instant before adding full power, I looked down to ensure the pilot had correct foot placement on the rudder pedals. To my surprise the pilot had removed her feet from the pedals and had placed them flat on the floor.

When asked why she had done so, she replied that her instructor had told her to do that!

At first I thought it was an attentiongetting prank to test me, but she was dead serious. After the flight I gave this some thought and mentioned this situation to another instructor. All we could come up with was “unbelievable!” How could a student obtain a private certificate using this method?

Transitioning from a tricycle to a tailwheel (conventional) gear airplane is great fun, somewhat challenging, frequently frustrating early on, and almost always humorous. I’ve experienced this and more while training new pilots, but it is especially good for a lot of chuckles when working with a certificated, tricycle-experienced pilot.

I’ve trained pilots, both new and experienced, in a lot of different tailwheel airplanes, but I prefer to start them all in the J-3 Cub for a couple of reasons. The student sits in the back seat, with me in front. Positioned in this configuration, the student can see my raised hands when I use them to demonstrate rudder inputs on takeoff and landing. While in flight, I can reach down and place my hands on their shoes and “assist” with rudder inputs when making and rolling out of turns or when maintaining directional control on either the takeoff or landing roll. This method also teaches attitude flying.

Proper Foot Position Is Vital Before ever starting the engine, it is important to have the student get settled in the rear seat. The first thing he usually does is place his feet on the rudder pedals so that the arches of his feet make contact with the pedals. It is very important at this stage to reposition his feet so that the ball of each foot is lightly making contact with the rudder pedals. This allows the foot to pivot at the ankle when applying rudder input. Rudder inputs will be much more fluid and more easily coordinated with aileron inputs, as it requires only ankle pivot. If the arch of the foot is in contact with the rudder pedal, the entire leg has to move to provide rudder input. This action leads to uncoordinated inputs when applied with the ailerons, and we’re always striving for smooth, fluid, coordinated control inputs.

The first question a transition pilot will usually ask is, “I can’t access the heel brake pedals with the balls of my feet positioned this way. How do I do that?”

My response is, “You only use the brakes three times for a Cub flight: when starting the engine, when doing the engine run-up, and when stopping in front of the hangar at the flight’s conclusion. Yes, there are exceptions, such as when taxiing in close quarters or taxiing in a strong wind. But otherwise, if brakes are needed, you’re ‘behind’ the airplane!” In those three situations it is satisfactory to use toe pressure on the brake pedals to prevent pain and strain on your Achilles tendon.

During the first hour of flight in the J-3 Cub, or any tailwheel aircraft for that matter, rudder usage can usually be categorized according to one of the following descriptions: Calf-Cramping Crush: This occurs when one firmly plants both feet on the rudder pedals and applies equal amounts of foot-crushing pressure so as to nearly rip the rudder pedals from the floorboard. This method of rudder

How could a student obtain a private certificate using this method?

30 SEPTEMBER 2011

usage will also cause severe leg cramps later in the day.

Toe-Tickling Touch: This involves just barely touching the rudder pedals for fear of “breaking” something. This input or lack thereof leads to significant adverse yaw whenever attempting to bank the airplane.

Monster Mash: Slamming the rudder pedal to the floor with a size 14 steel-toed work boot whenever a slight bit of rudder input is required.

Severe skidding turns are the usual result, followed by an equally hard skid in the opposite direction when rolling out of a turn and returning to straight and level flight.

Arch Pivot Push: Placing the arches of the feet on the rudder pedals so as to cause unusual ankle contortions with little or no rudder response. Shin splints are sometimes the result of this method of rudder application.

Footrest Roost: Attempting to fly a tailwheel airplane with tricycle-plane inputs. For someone attempting to taxi using this method, the rudder pedals serve as footrests, never to be moved except when taxiing. One will usually see a lot of rapid foot movement in search of the toe brakes, which are not there.

Fluttering Fish: Rapidly moving the rudder from stop to stop, thinking this will help maintain directional control on takeoff or landing.

Watch for this type of rudder movement at the next pancake breakfast, and you will see that the rudder is but a blur until the airplane becomes airborne or comes to a complete stop on the runway.

Around-the-Clock Rock: The act of unconsciously pushing the rudder pedals left and right, usually accompanied by moving the control stick or yoke left and right but not in a coordinated fashion. Frequently induces nausea in a beginning pilot and most often occurs on final approach to land.

Tap and Release When explaining proper rudder usage to a tailwheel transition student for takeoffs and landings, I use

the phrase “tap and release.” With the stick or yoke back and the aircraft aligned with the runway centerline for takeoff, rest the balls of your feet very lightly on the rudder pedals. Do not yet exert any pressure. As you begin smoothly applying full power, the plane will generally want to yaw or swerve slightly leftward. Tap and release the right rudder pedal one or more times. Do not push the right rudder and hold it, as this will immediately cause an overcorrection and the nose of the plane will now be pointed rightward. In order to keep the plane tracking straight forward, the right rudder may need to be tapped and released several times.

As the control stick or yoke is moved slightly forward, raising the tail about a foot above the ground, you will again experience a slight leftward movement of the nose.

Tap and release the right rudder as needed to correct this movement, keeping the aircraft tracking straight forward.

One common mistake I see when teaching takeoffs to both transition and first-time tailwheel students is the attempt to move the airplane back to the runway centerline after the aircraft has been allowed to yaw leftward. In my opinion, this should never be done. Rather, straighten the ground track of the plane and continue the takeoff from that point forward. Attempting to move the airplane back to the centerline will usually induce an interesting S-turning ground track, often leading to a spectacular trip between and sometimes over the runway lights.

Once airborne in a proper climb attitude, slight but constant right rudder pressure is needed until completing the climb, offsetting the engine torque and propeller P-factor.

This is the only time throughout a normal flight where constant rudder pressure is required, with one exception: steady crosswind landings.

Another common rudder usage mistake I’ve experienced is continuing to hold the rudder input when making turns in flight. Several days ago I was working with an experi-

enced pilot on a tailwheel transition.

Every time he turned, he applied and held the rudder until completing the turn. When I corrected him, he told me that his instructor had taught him to do that. Once the desired angle of bank has been established, the control stick and rudder should be neutralized. By that I mean move the stick to the center, removing the aileron input, and take your foot off the rudder. Most of the light singleengine airplanes we fly have a fair amount of positive stability designed into the aircraft. Few or no control inputs are needed after establishing the bank angle to complete a 90-degree shallow-bank turn until rolling out to a wings-level attitude at the turn completion.

When landing, it is important to take a deep breath while on short final so that your muscles are relaxed. This is where one of the seven rudder mistakes most often occurs. Unknowingly, we allow ourselves to get tense in preparation for a tailwheel landing.

Keep the airplane aligned with the runway during the level-off and flare by using slight rudder inputs, again tapping and releasing the pedal each time pressure is applied (except in a crosswind landing). Upon touching down, tap and release the appropriate rudder pedal, keeping the plane on a straight-line track throughout the rollout phase of the landing.

Pushing and holding the rudder will cause overcorrection, leading to another series of runway S-turns. Just tap and release and repeat as necessary to keep the airplane straight.

Again, if the airplane is allowed to drift a few feet left or right, straighten it out with rudder tapping and continue the rollout straight ahead from that point. Do not try to realign the airplane with the runway centerline.

Learning to safely fly a tailwheel airplane is challenging but also a lot of fun. It will teach you to use your feet and make you an all-around better, safer, and more coordinated pilot.

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