Fike E

[Jose Luis Nogueira]

Hello

I build the Fike E from the plans of Peter Miler, but the plane was very instable. The CG is in the place indicate on the plan, but when i push the elevetor down the aircraft down abrup whith a dificult recover.

If someone have the same problem, please post the solution.

Thanks, Luis

[Piers Bowlan]

This is the build article from March 2003. I have no experience of this model Jose but hopefully somebody will be along soon who has. Peter, where is he when you need him? The model looks fairly short coupled so might be quite sensitive to small changes of C of G. Have you tried moving the C of G a little further forward to see if there is any improvement? Perhaps you could also try reducing the elevator throw slightly. Hope you get it sorted.

[Peter Miller]

Hi Luis

Sorry that you find the Fike unstable. Mine was fine and very aerobatic including low level inverted.

I have gone back over the plans and article and cannot see why it should have the sudden dive with down elevator.

The wing is set at true zero incidence. It is possible that somehow it has a fraction of negative incidence so you could try packing up the leading edge a little and seeing what that does. It certainly will not do any harm.

One way to check this incidence is to set the model on a flat surface. Measure from the centre of the curve of the leading edge to the table and from the trailing edge tpo the table. These should be the same.

Then do the same for the tailplane and elevators. Again the leading edge and trailing edge should be the same distance from the table.

Finally while the model is still set up check if the engine thrust line is parallel with the surface.

This should show up and rigging angle errors

[Jose Luis Nogueira]

Thank you Piers and Peter,

I will make the changes that you write in the post, and test the Fike E.

Regards Luis

[Gary Manuel]

Great when you can ask a question on a public forum about something you've built from a free plan and get an answer from the designer in a few hours