Modified Denny Dart Mk II H First Flights

Last night I made the changes I saw were desirable in the first plane; I added a 1/32″ shim between the tailplane trailing edge and the stick to reduce the tailplane incidence and I changed the canting of the dihedral break lines to 1/16″ offset right at the leading edge and 1/16″ offset left at the trailing edge.  It was very windy today, but got quiet at twilight.  I took it to the small local park for short test flights.  The plane flies beautifully.  It circles left all the way to the ground.  It recovers from a steep climb and transitions smoothly to cruise.  This one weighs 6.95 gm.  CG at 0.6″ behind wing LE gives nice slow glide.  Quick flights made at the park after sunset were made with a 10 1/2″ loop of 3/32″.  400 turns made a nice level circle.  900 turns got close to going out of the park.  See the attached video.

Here you can see the reduced cant to the dihedral lines.  Still enough to resist left torque roll at maximum turns, but the rudder and slight sidethrust can maintain a left circle.

Here you can see the shim on the tailplane.

I made drawings of the final configuration. The tailplane incidence is 3/16″ in 2″ or 5.36 degrees, compared with 6.24 degrees before.

You can copy and print it on 8 1/2″ x 11″ paper. Full span flat is 15″. I block the center section up 1 1/2″ for dihedral. It would fly nicely indoors, too.


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