Gravity Always Wins - The 4 Forces Acting on an Aircraft

The 4 forces acting on a weight shift control (WSC) aircraft in flight are lift, thrust, drag, and gravity. Of these gravity will always win unless energy is expended. In WSC flex wing aircraft and ultralight trikes students always seem to have a problem with this concept. When landing, the control bar is pulled in to increase energy and power reduced beginning the decent and increasing airspeed. When it comes time to round out or flare students have a tendency to not only allow the control bar to return to trim but push out rapidly. This results in ballooning where the aircraft rises and rapidly losses energy (airspeed) and can result in a stall while the aircraft is still a foot or two off the ground. In serious cases of ballooning the aircraft stalls higher and results in a bounced landing if your lucky, something more expensive if your not. Once ballooning starts the student will try to counter by pulling in. This makes the problem worse since the aircraft is now slightly nose down and rapidly approaching the ground. So the student pushes out again, back and forth like sawing wood, a nightmare for the instructor who is watching their life flash before their eyes and trying to correct the problem. The solution to the problem - sit back relax and realize that Gravity Always Wins.

First abort the landing and go around, allowing the student to demonstrate good aeronautical decision making skills (in other words please don’t slam me into the ground). Then try again, If when rounding out or flaring the power is at idle and control bar is allowed to return to trim, the aircraft will have the correct attitude and will eventually settle on its own. Obviously, this applies to calm conditions without cross winds but that’s the best training air and your not trying to land on a postage stamp, right?

Another useful tool for correcting problems with either timing or altitude when rounding out is the low pass. If the student can fly the length of the runway at 1 foot then they got it. If not then more practice.

Digital Airport Facilities Directory (AFD)

Airport facilities directories are useful tools for flight planning and every pilot has a copy. The problem with these little green books is they have a very short life span expiring about every 3 months. If you are not close to a pilot shop, like the Sky Gypsies, it is difficult to keep an current version of the AFD. Well the AFD is now online courtesy of the FAA.

A current AFD is especially important when testing since the designated pilot examiner (DPE) will require the applicant (us) to have a current copy for the ground portion of the test. But thanks to the FAA that will not be a problem, just go online and either download the latest version for the test or connect to the site during the oral. Demonstrating the ability to access relevant information on the FAA’s website also demonstrates good aeronautical decision making skills, something DPEs always like to see.

Free, The Weight Shift Control Flying Handbook.

With the takeover by the FAA everything has become more uniform for weight shift pilots, one organization that oversees training of trike pilots and registration of aircraft. While the merits of this have been debated endlessly one thing is clear - the process moves forward. The Weight-Shift Control Aircraft Flying Handbook has been published by the FAA and is available online from several vendors. Aside from providing standardized information for training and testing, the great thing about this book is you already paid for it. Your tax dollars went to pay the author and you can get as many free copies as your hard drive can hold. That is one of the good things about the FAA, they tell you what you what the rules are (the FARs), they tell you what you are required to do to get a pilot ticket (training requirements), and they give you all the information to accomplish the task. It is all free, just go and get it. It is even possible to complete a light sport CFI with the information the FAA provides. The system is set up to help you pass and get your ticket.

You can find a link to the Weight-Shift Control Flying Handbook under weight shift aviation links in the sidebar or you can just go here.

Leave a comment and let me know what you think about this new training tool.