Apparently we are able to grow older, partly by virtue of the knowledge accumulated from our non-fatal mistakes. At least we should be able to avoid repeating those potentially fatal or hazardous situations. About 14 years ago my leg required 18 stitches to close a wound caused by the propeller on POGO I. I immediately gained a lot of respect for the potential of a "small" Super Tigre .60 powered 29% scale airplane. This incident was caused by my fingers contacting the back side of the propeller while adjusting the engine needle valve. This was no problem but I was startled and released the airplane at full throttle into my leg.

While the doctor was sewing me up I thought about a friend's full scale incident. In his student days he was anxious to build up his flying hours. No one was at the small field when he arrived, so he proceeded to put a chock under a wheel and do his own propeller flipping. In the process he got the engine flooded, then advanced the throttle to clear it but forgot to turn off the mags. The engine started on the first try and he immediately thought of his mistake. He made a dive out of the way of the propeller as the airplane pirouetted around the chock. He grabbed a passing wing strut and managed to work his way toward the cockpit as the airplane made a circle or two on the ground before he reached the mag switch. He luckily didn't get hurt but he said his knees shook for a long time.

After my experience, I thought we need to have these "tigers" tails tied securely down the ground. This was the beginning of my tail tie-down designs for giant scale models. The first tie-down was made with a straight ten inch piece of 3/8" rod and a strap hinge. One strap was fastened securely to the rod with a generous wrapping of wire and some epoxy. A bolt, nut and "R" pin on the other end of the hinge was used to secure the tie-down to the airplane. A hole was drilled through the bolt for the "R" pin. This worked fine and was used several years. The main objection to this system was that it allowed the tail to move to the right or left an inch or two.

The present tie-down system was designed for the Quadra 35 powered airplanes and has been used with the Zenoah 23, 38, Quadra 40 & 42 engines. It has worked well in soft, hard and frozen ground. I use a long carbide bit and hand drill in frozen ground. I simply use a twisting motion for insertion of the tie-down in hard surfaces. The end of the rod is shaped like a screwdriver tip. This is somewhat slow, but I do not use a hammer since it would distort the rod.

A few local giant scale modelers have made their own tie-down systems similar to that shown in the photos for Zenoah 62 powered airplanes. This system, while certainly safer than wheel chocks, etc., should be designed, constructed and used with great care. Over the years I have seen a few propeller shafts break and propellers and spinners come off running engines. I try to aim the nose in the safest direction for others when starting and cautiously running up the engine. Incidentally, I give the airplane a forward "tug" just before starting to make doubly sure that the tail is tied down. I use the tie down wherever feasible, even with helpers.

Always return the airplane to the tie-down before attempting to restart the engine. Another friend did not do this because he was in a hurry and proceeded to put his hand in the propeller at full throttle resulting in severe wounds. It seems that my friends get into a lot of trouble!

The tie-down essential parts are shown in the photos. It is shown dangling from the tail of POGO IV to illustrate connection to the tail wheel assembly. It uses 1/4" hardware store steel rod and the strap part of a "T" hinge with the hinge hole enlarged to 1/4". After enlarging the hinge was re-rolled as necessary for secure fit around the 1/4' rod, using a good vise and hammer.

The rod was bent 90+ degrees and the hinge strap aligned for drilling the hole through hinge and rod for the spring pin that is used to lock the hinge in the tie-down and storage positions. Slots were carefully filed into the two hinge holes to provide for spring locking of the hinge in the two positions. A 9" length for the portion of the rod that goes into the ground has proven satisfactory over the years for engines up to Quadra 42 size. The tie-down hinge strap should be folded over parallel to the ground after the airplane is disconnected to prevent someone from tripping over the upright hinge strap.

Several years ago when the tie-down was first used, a few people thought I had brakes on my plane when I ran up the engine to full throttle with no one holding the plane. The tie-down also made an impression. I remembered leaving my tie-down at Tom Sawyer Park, Louisville, KY., when I was about half way home. Next year, a chapter member presented me my old tie-down as I drove into the park ... a great bunch of flyers!

Careful design, construction and use of a tail tie-down will, in my opinion, greatly improve safety in one of our most hazardous operations ... engine starting.

A tie-down similar to that in this article is available at A.H.A. Manufacturing, 13 N. Main St., Centerville, OH., 45459, Phone 513-433-0752.