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#219 Ground Loops (Gulp!)

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Written 5-2-18

 

I find it kind of interesting that ground loops and other “taxi”, or ground-based accidents are so rarely talked about when, in fact, the groundloop is the most common tailwheel accident and the one which I believe the nosewheel was invented to prevent!

So, I think that we ought to take a look at the number one cause of the groundloop.  This is my opinion:  Lack of heading control.  After all, if an aircraft is landed off runway heading, that heading will simply start its rather rapid turn which the pilot may not be able to stop.  So, shouldn’t we be spring-loaded to maintain runway heading?  Similarly, shouldn’t we use a bit of our training time to have an applicant run up and down the runway, perhaps while doing some small slaloms to each side of the center line in order to get the feel of the aircraft’s desire to turn and, more importantly, to increase the speed of its turn?

I think the answer to the question above should be a resounding “YES!”

That is why, at Tailwheel Town, the flagship maneuvers are Multiple Landings and Landings in a Turn (videos of those maneuvers can be found on www.tailwheelersjournal.com).

Flight instructors are the main culprit here, and I’ll admit that I’ve been one of these culprits from time to time.  You see, us flight instructors seem to feel that the “Flight” in our title means that we do our teaching while flying.  In the case of taildraggers, that’s really not necessarily true.  If we are trying to avoid groundloops, we’ve gotta make sure that the airplane is landed and taken off with its heading the same as runway heading. Lately, I’ve been trying to simplify the pilot’s thinking about slips and skids by simply stating that it’s “Rudder for heading and aileron for course”.  It works.   If I had a moldy twenty for every time I’ve said that “on landing, the plane’s heading, it’s course and the runway’s heading MUST be identical”, I could retire with moderate wealth.  But I’ve also extolled the importance of practice and it is only through practice of maneuvers such as the landing in a turn and multiples that a pilot can truly perfect the skills necessary to perform these maneuvers and made ourselves “Ground Loop proof”.

When I was teaching with a Cessna 140, I had small squares of black tape on the cowl and the windshield.  When those two squares of tape were lined up with an eye of the applicant, they pointed in a direction parallel to the longitudinal axis of the airplane.  That was so that, even in a side-by-side aircraft, we would be sure to know where that axis was pointing.  That’s not so important in an in-line airplane like the PA12 or a Cub or Champ, but the principle is the same.

And let’s not forget that some of us will revert to the actions of a guy who is driving a Soap Box Derby racer.

The Illustration below shows the problem created when we think that the rudder bar is like that of a simple “soap box” racer.  It’s backwards!

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Also, the difference between a stick and a yoke must be addressed.  And if an applicant depresses the wrong rudder pedal when the airplane departs from the heading, that is going to immediately aggravate the problem.  Remember when I wrote an article in which I stated that the student pilot who failed to immediately increase his bank and head for the runway in the event of an engine failure on crosswind wasn’t ready to solo? Well, the same is true with certain other skills, like depressing the correct rudder!  Some may poopoo this statement, but I don’t think it can be denied that for some people the instinct to treat the rudder bar of an airplane like that of a “soap box derby racer” will be paramount.  And to succumb to that instinct is deadly and will result in aid to the “ground loop demons”.

Another issue confronting the new tailwheel pilot is that of using the aileron to “assist” the rudder.  You see, many low-time pilots see the rudder as the only control necessary to control the heading of the airplane during a landing or takeoff. Sorry, but that just isn’t true. Because to use the rudder alone to control the course and heading of the airplane in a turbulent airspace during a takeoff or landing is to skid the plane like crazy.  It’s just as important (and as easy) to coordinate turns while touching the ground as it is when in flight and not touching the ground.  An airplane with one wheel on the ground, turning across the runway, has just as much of a need to be coordinated as one that is in the air.  When I teach slaloms with the airplane on one wheel, then the other and going back and forth across the runway, I see the usual mistake.  The mistake I see more than any other is that to use too much rudder, which skids the plane back and forth.  And it’s ridiculously simple for the airman to feel his upper body and use coordinated rudder and aileron.  But, no! Most applicants, when they first experience this maneuver, tend to use far too much rudder and to skid the plane. What is heartbreaking to me is that all they have to do is heed the warnings of their upper body as it hinges on their butt and use their rudder to center their upper body.  Man, how many times have I said that!  Lots and lots!

And let’s not forget “Duncan’s Theory”. What’s that? Well, it’s in my book, but Bill Duncan, who used to own Alaska Bushwheel felt that tailwheel steering might have caused more groundloops than any other cause!  He felt that if you were landing in a crosswind, while holding some rudder, when that tailwheel contacted the ground, it would immediately snatch the airplane’s heading to match the tailwheel’s orientation.  I think he was right.  So, the ability to judge when the tailwheel is going to touch and to, at that moment, neutralize the rudder, could be really important.  At the very least, it will cause your landings to be smoother and prettier!  I consider that action to be somewhat advanced and don’t always teach it, but it’s a good one!

So, think about ground loops.  Talk about ground loops.  And practice those maneuvers which will make you and your airplane “Ground Loop Proof”.  It’s easier than you think!

Happy Swooping!

Brian