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The Mighty PT-17


So back into the shop for repairs and more MODIFICATIONS.


PT 3


Note aileron torque rod position is too much; it caused binding and loss of control.


PT 4


Note aileron torque rod position. This is all it took to avoid binding!   This setting provides for excellent roll response.


While the Mighty PT-17 was laid open I took the opportunity to increase the down thrust to mitigate the “ballooning” on full power.


PT 5


That’s a lot of down thrust.


These modifications made the airplane fly just great. I flew it so much that I wore out the motor and battery and it just started to not take a charge well and the motor needed the dreaded “flick” to start and the wings were floppy from so much damage and I chose to retire “The Mighty PY-17”.


But, as luck would have it, your Editor-in-chief just happened to have an extra PT-17 for sale and I gladly bought it and immediately cut it open and swapped out the bellcrank , added more down thrust, and replaced the battery Velcro with a better grade so as not to lose the battery in flight as the stock Velcro is want to do. Still, this plane is kind of pitch sensitive. I have noticed the leading edges are cut a little bit more sharply than the last airframe. This made me think I should do more MODIFICATIONS!


So I took the old airframe and added leading edge inserts. I tried to make the leading edge radius symmetrical while still leaving enough under camber to keep flying speeds down. These had numerous effects that I still do not have definite answers for.


PT 6


Leading edge inserts.


PT 7


Achmed (the dead terrorist) supervises.


PT 8


This photo shows the leading edge radius modification. (and a lot of battle damage as well )


All I can say is: WOW, what huge difference in flying capability. This totally transformed the flying capability of this airplane. It is no longer pitch sensitive as the stock airframe is. Outdoor flying in the wind is now a pleasure due to the vastly improved penetration. Roll response with the stock bell crank is now completely acceptable ( it is still no Pitts ) The extra down thrust is now no longer needed and I will remove it next time I have an “opportunity” to modify it once again. It flies noticeably faster and yet it slows down for landing OK. All in all, if you fly outside , as I do, this is a great modification. Inside loops, outside loops, Cuban 8’s all are much better. I have not tried snaps or other maneuvers yet.


In conclusion;


If you fly primarily outdoors this is THE modification to perform.


If you try this modification do not use balsa wood! It is too heavy. Stock weight is 44 grams, with this modification. It now weighs 49 grams! That is a stunning 10% weight gain ! Depron would be a better material. I believe the higher flying speed is in part, due to the excessive weight increase.