• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.

Morphing an Airplane --Aft Swept Wing to Forward Swept Wing in Flight

L Edge

Well-known member
#1
After building and flying my F-14 "Tomcat" with variable aft swept wing, did some research(2012) and found no one tried to morph it into a forward swept wing. So researched structual and aero problems to see what needs to be done to get one to fly.
This is what I started with:

P1010037.JPG

To this:

P1010038.JPG

Then I did this:

P1010035.JPG

This lead to me going to play around with the same plane to see if I can make the offset oblique fly. So here is an another area very few have explored.and I am going to see what happens.

If you let your mind go, how about a forward swept wing placed in the rear and now have it move forward to produce a delta wing fighter. You have now a future Northrop/Grumman F/A -37 TALON.

So now after designing and flying an AFT/FORWARD SWEPT WING, I now have 2 new projects. The Talon has been tried and flown, but the wing has folded and those who have tried to scratchbuild a FSW, know the problems that exsist. After exploring, I am sure I can make it fly, but the structual problems still exist.

Here is what the Talon looks like.

https://en.wikipedia.org/wiki/Northrop_Switchblade

Trying the offset oblique is going to be a challange. As scratchbuilt designers know, the life of a design plane sometimes gets to be very short before it is destroyed.
 

L Edge

Well-known member
#2
After completing the "Tomcat" so it moves the wing aft by the throttle, got the idea to try morphing the aft wing upwards to fly a forward swing wing config while it is in flight. So the project began with exchanging one servo for two, so each servo would swing the individual wing. Rather that start from scratch, decided to use maybz F-14 "Tomcat" design(asked permission) on RCGroups, and modified it with the two servos plus some other arrangements.

botview.JPG

As you can see, maybz "fuse" is solidly built even without any carbon rods and has stiffness throughout the frame. Yet, it still is light which is what I want. Notice that the 2 servos are located within the channel and allow for bonding the servo not only to the bottom frame, but the side of the servo given it a good surface area to fight the external forces of the forward swept wing.



A closeup of a servo

IMG_0175.JPG

Figured out that aft wing, forward swept wing CG difference was about 3 inches, so to help the situation I moved the location and shape of the wing so I got it down to about 1". Then reshaped the aft fuse so the wing closed to it in the aft position. All done on brown meat paper rather than any computer program. I am a product of the "old school method".
 
Last edited:

L Edge

Well-known member
#7
Now that I know the fuse and servo will take the stress, the wing is the big problem.

topwing.JPG

This is the top shape I ended up with to deal with the wing bending and twisting. Again, trying to keep the weight down for CG, I was going to use carbon strips around the leading, side and trailing edge . But decided to use a dual carbon rod and take a chance.

botwing.JPG

Sidestep: Did you know that a car/truck can be your wind tunnel? After I glued it in and set up the rest to the plane, I had a friend join me for a ride locally and then the interstate for speeds up to 70 mph to do my wing testing for flutter. I passed with the wing being perpendicular and then moved forward 5 degree intervals to about 30 degrees. Used a tx pot to control the deflection. Hey, it passed the test.
 
Last edited: