Saturday, February 6, 2010

Thoughts On Landing Touchdown Targets and Touchdown Zones

What is the landing touch down target for your landings?  Do you use one? I know most of us are  interested in demonstrating our superior pilot skills by making smooth landings.  In the effort to achieve a smooth landing most pilots will ignore one of the more important goals for landings and that is a touch down on the prescribed touch down target within the touch down zone. A landing on or close to the touch down target will result in a longer length of runway remaining to decelerate and stop enhancing safety.  It will also prevent a landing short of the runway.

I learned to fly in a Piper PA-12 Super Cruiser while  attending Kent State University on a runway that was 3,000 feet long. The flight instructor's name was Leonard Mack.  His preflight briefing for my first effort and landing and takeoff included a rough runway drawing on a black board.  Mack divided the runway into thirds as well as dividing it in half.  He created a touch down target by drawing an X in the middle of the first third emphasizing the importance of having an aiming point for the landing.

He went on to add the criteria of as long as a touch down occurred within the first half of the runway, a deceleration and stop would happen safely. Mack established the rule that says if your aircraft is not able to touch down in the first one half of the runway, a go-around is mandatory. These rules have proven to be of value for more than 40 years for me. They worked no matter what length runway I landed on or what specific aircraft I was flying.

The airlines have established guidelines with similar values.  For example, when I was flying a narrow body airliner like the Boeing 727, the touch down target was specified to be a point 1,000 feet from the approach end of the runway.  If I was flying a wide body airliner like the Boeing 747, the touchdown target was a point 2,000 feet from the approach end of the runway. The primary purpose of these guidelines was to prevent pilots from experiencing an undershoot or touching down short of the runway. As the Boeing 747 was a much longer length aircraft, the touchdown target had to be further down the runway to assure an undershoot would not take place.

The airlines added the requirement that if a touchdown would not result in the touchdown zone a mandatory go around maneuver was required.  The touch down zone was defined as a space that began at a point 500 feet prior to the touchdown target to a point 500 feet beyond the touch down target. Landing beyond the touch down zone was never recommended.

A "good landing" simply requires the pilot to be able to "walk away" from the aircraft.  A "great landing" is defined as one in which the airplane is capable of being flown again.  A "perfect landing" requires both of the above plus a smooth touchdown in the touchdown zone.  Most  pilots I have observed are willing to trade off the requirement for touchdown in the touchdown zone to achieve the smooth landing.   This is not a worth while trade off in my opinion.

In my experience a perfect landing only happens about once in every 100 landings. How often do you experience a perfect landing?

Thanks for taking the time to read my blog.  If you have a blog, please direct me to it and if appropriate we can link them up.

4 comments:

  1. I do very smooth landings, but they are rarely in the spot I picked. I let the airplane glide until it has no more willingness to fly and then I do a smooth landing. I would like to learn how to land in the same spot every time.

    David Velez

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  2. Hi David,
    So would I! As a suggestion, accurate air speed control is the key to predicting your touch down point. Most pilots will have excessive airspeed which makes it difficult to control their touch down point.
    I am headed to the airport this morning to hang out.
    Thanks for visiting my Blog. I am getting ready to advertise it to every one. Do you have any suggestions on how it might be improved?
    Thanks!
    Dick

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  3. I came across your blog while Googling my name. The Leonard Mack you mentioned as your flight instructor was my grandfather, for whom I am named after! It is a small world sometimes! unfortunately, he passed away before I was born, but I recently kept up his love of flying by getting my pilots license about 5 years ago.



    Leonard M. Mack, II
    leonard@leonardmack.com

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