Last Monday, Walt Moore, Bill Womble and I met at the field for some flying and "just sitting
and talking airplanes". Bill had brought his Four Star .60, powered with his new OS .70 four stroke. This airplane has many
hours on it, but he had just acquired the OS .70 and was still trying to find the "right combination" of fuel, prop and
trim.
Bill had made a few successful flights trying different prop/pitch combinations and was just taking off with what he felt
would be the right setup. The wind was almost non-existant - 4 mph and just slightly left of "straight down the runway".
Bill made a picture perfect lift off and was in a shallow climb and slight turn to the left. His altitude was about 8 feet
and he had just cleared the runway when it happened!
Suddenly the Four-Star made an abrupt pitch down and to the left! Bill immediately pulled throttle to idle and tried to
correct, but there just wasn't time or altitude. The airplane made a dis-heartning "Cruuump" and silence!
It looked exactly like he had been "hit". Bill was flabbergasted. As he pushed the transmitter antenna down, he said
he had never suffered a "hit" before and he was adamant that it was NOT "pilot-error". I agree -- it was not pilot error!
No pilot, and especially not Bill, would push full "down stick" and left aileron at that critical time during take off.
As it turned out the airplane was only slightly damaged. Thank goodness for nylon wing and landing gear mounting
screws! A bit of damage to the wing tips and one crack in the fuselage. Easily repaired.
But why did it happen? We determined to see if we could find out. After we had carried the airplane back to the pit area,
we checked the radio and all controls worked normally. We decided to carry the airplane back to the approximate point where
the mishap occurred and see if we could duplicate it. I suggested Bill and Walt carry the airplane so Bill could see what (if
anything) happened and I would stand where Bill had been standing and hold the transmitter.
Bill started to hand the transmitter to me pulling out the transmitter antenna and -- it came ALL THE WAY OUT! We found that
it had come unscrewed from the RF module inside the transmitter. We were able to duplicate, almost exactly, the mishap by
carrying the transmitter away from the airplane (with the antenna still loose) and at the almost exact distance, from transmitter to
plane, the elevators went full down and the ailerons full left! (Possibly, the throttle serevo moved to full idle also and Bill
really didn't have ANY control, even though he had pulled the throttle stick back.)
After re-attaching the transmitter antenna all worked well!
So! Make an adjustment to your Pre-flight: If your transmitter's antenna "screws in" - check it before each flight!
See you Next Month ... Ron
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