More than 4 hours in flight!

Model Airplane News, Nov 2001 by Wilder, Bob

FINAL APPROACH

Like many modelers, I'm enticed by a challenge, and I could not resist this one. Designing, testing and building a new concept in model aviation appeals to me. This quest began when I first read about AMA event no. 627, "Indoor R/C Electric Duration."

On my earlier record flight of 2 hours and 34 minutes, I used rechargeable batteries. Sometime after I set that official record flight, I made an unofficial test flight using some non-rechargeable, one-shot lithium batteries. That flight lasted 4 hours, 11 minutes.

In preparation for my attempt to establish a new official record, I changed some of my equipment, such as the receiver and electronic speed control (ESC); I also switched the motor and gearbox. On the test stand in my workshop, I performed a few test runs and decided that it would be necessary to use only three lithium batteries for my official flight. I changed the standard 600mAh Ni-Cd batteries in the transmitter to 1300mAh NiMH batteries.

One obstacle in my path was finding a good place to fly. My wife, Mary Ann, suggested that I contact the engineering department of the University of Texas at Arlington (we have two sons who are UTA graduates).

The staff of the college's engineering department received us enthusiastically, particularly when we told them that the current record had been set by Dr. Tom Avedisian at Cornell University! There's nothing more invigorating than the spirit of collegiate competition.

We applied to the AMA for a record trial sanction, and Ernie Harwood agreed to serve as the contest director, with Greg Judy, Bill Maserang and Ron Hanna stepping in as official timers. On Saturday, June 30, 2001, we arrived at the UTA Activity Building at 9 a.m. sharp and were airborne by 9:14.

The room we flew in was about 150 feet square with about a 30-foot ascent to the rafters. The airplane was airborne only briefly, however, when it became apparent that the air conditioning was blowing up a storm! The model was difficult to control with it on, so it was turned off. Things settled down then, and I tried to relax for a while.

This model had only rudder control for direction and motor speed control for altitude. I learned from past experience that I could have good control of the model just by using the trim-adjust levers on my transmitter. Only during the turbulent flight time with the A/C on was it necessary to use the transmitter-- control sticks.

During the official flight at UTA, my good friends Bud Tenny and Jim Clem came by to cheer me on and offer words of encouragement. Two UTA engineering faculty members also stopped by-Drs. George Dulikravich and Don Wilson. As it turned out, Dr. Dulikravich and Dr. Tom Avedisian know each other. Small world!

After each hour of flight time, someone photographed me. After three hours, I had a big smile on my face, as I was on my way to establishing a new record. The throttle setting on my transmitter indicated that I still had a lot of battery power left, or, as the expression goes, "... some gas still left in the tank." At the four-hour mark, I could tell the battery was near the end. At four hours, 17 minutes and 57 seconds, the model touched down with the motor still running.

The question most people ask when they hear that I flew nonstop for over four hours is, "How did you do that without a potty break?" Simple. I bring kitty litter.

Occasionally, I get a more serious question such as, "Can you make your model fly inverted or do an outside loop?" I reply that it is all I can do to keep it from hitting the walls or rafters for four-plus hours.

Actually, it felt good to be in the same class as a modeler like Tom Avedisian!