Mar 2010 The Infamous Ground Loop!
While airport hopping yesterday, Boyd and I struck up a conversation with a really nice guy flying a Cessna 180. Â He said he’s been flying over 50 years, many of them in the 180, and in all that time had never been involved in any kind of incident or accident – until the day before! Â He wasn’t the pilot and was just flying along with an old friend in his taildragger when things got a little “ugly” on takeoff. Â A lax takeoff quickly got out of hand and resulted in a pretty messy ground loop. Â Anyway, his story was a good reminder to me that no matter how long you’ve been flying, you can’t get too comfortable or too relaxed when you’re in a taildragger.
So what exactly is a ground loop? Â If you are flying a taildragger, no doubt you know and, hopefully, are focused on every landing to make sure it doesn’t happen to you. Â If you are considering flying a taildragger, you NEED Â to know; a ground loop, simply put, is when the front end of your airplane switches places with the back end.
During take-off, and especially during landing, taildraggers areÂ directionallyÂ unstable – stability is the function of the pilot. Â Any swerving movement on the ground has the tendency to tighten and, if not corrected by the pilot, can result in a ground loop.Â In a crosswind, a taildragger will tend to weather-vaneÂ into the wind increasing the possibility of a ground loop. Â This must be counteracted by the pilot by keeping the tail firmly planted on the ground, applying theÂ appropriateÂ amount of opposite rudder and keeping the wing that is into the wind down.
This video is stuffed full of actual video shots of taildraggers experiencing ground loops. Â It also shows some unbelievably uncontrolled tricycle aircraft moments before touching down and howÂ miraculouslyÂ forgiving a tricycle gear aircraft can be. Â And lastly, it offers some basic and necessary simple instruction on how to land a tailwheel aircraft correctly.
These few paragraphs from Dodgen Aircraft Training are a reminder to even seasoned tailwheel pilots and a must read for student and low time tailwheel pilots:
The ground loop is probably the most feared occurrence that pilots think can happen in a tailwheel aircraft. It is also what most frequently causes damage to tailwheel aircraft. A ground loop is something that need never happen in a tailwheel pilotâ€™s career as long as they understand the limitations of their aircraft, their ability based on their piloting experience, and how to properly avoid letting the aircraft get into this condition.
The ground loop is when the tail of the aircraft loses directional stability and rotates about the horizontal axis of the aircraft. This leads the tail to want to spin around the nose of the aircraft as it is disturbed from a straight line. When this happens, the momentum will carry aircraft partway or potentially all the way around until the tail of the aircraft is headed in the direction that the aircraft nose was originally aimed if no correction is made.
In many cases, the momentum will cause a wing to dip and may cause a wing strike on the outside of the ground loop, leading to a cart wheeling effect in which the other wing will be caused to strike as well. As the ground-loop happens, directional control is lost and the aircraft will frequently travel off the runway surface and be subjected to the potential hazards that exist off the runway such as lights, ditches, or unimproved surfaces. There can be no doubt that this can cause damage that may range from minor to very severe and is something that no pilot would choose to do.
To avoid ground looping an aircraft the pilot will need to be able to maintain proper rudder control at all times, even through what most tricycle gear pilots will consider a moderate or slow taxi. Tailwheel aircraft have the ability to ground loop to some extent at virtually any speed of travel above stopped, the speed simply controls how much momentum will be available when the aircraft ground loops. This momentum will determine how far or bad the ground loop will become if it is encountered. It is for this reason that the pilot should taxi slowly, perform landings that will allow for appropriate stopping and get themselves to a controllable taxi speed as soon as possible when landing.