I was going to design a plane on Tinkercad and I thought that I could make a instructable out of it and here are the instructions to the biplane.

Step 1: Step 1, Start of Wings:

Make a half cylinder and change the size to 20mm by 50mm by 2mm as shown in the pics above. Now duplicate the wing and bring it upward 10mm. Group the wings together now.

Step 2: Step 2, Finish the Wings:

Make a box and scale it to 20mm by 2mm by 10mm. Now put the box on the edge of the wings as shown in the pics. Duplicate the box and move it to the other end of the wing. Now group the wings and the boxes together.

Step 3: Step 3, the Body Pieces:

For this step get another half cylinder and scale it to 20mm by 50mm by 10mm. Also get a paraboloid and change the size to 20mm by 20mm by 14mm. Now slice the paraboloid in half.

Step 4: Step 4, Make the Body:

Now rotate the half paraboloid 90 degrees. After that move the half paraboloid to the ground. Then duplicate the paraboloid and move it along the half cylinder to get it to the other side as shown in the pictures above. When the paraboloid is on the other end, mirror it to look like the pics. Now group the paraboloids and the cylinder together.

Step 5: Step 5, Put Together:

Take and select both items and press the L key. Take the curser and press the middle circles on the ground like shown in the pics. When the two are aligned, group them together.

Step 6: Step 6, the Tail Fin:

Make a wedge and size it to 4mm by 10mm by 20mm as shown above. Now take the wedge and duplicate it and move it over 10mm and mirror the top and side like the pictures show. Then lower the length of the upside down wedge from 10mm to 5mm. Finally group the two pieces together.

Step 7: Step 7, the Tail Wings:

Make a roof shape and make the size of it 4mm by 50mm by 15mm. Then when you have that done you should rotate the shape 90 degrees as show in the pics. Then click on the roof and press the D button on the keyboard.

Step 8: Step 8, Put Tail Together:

For this step you will need to select the tail fin and tail wings. When that is done you can press the L key on the keyboard and align the pieces as shown in the pictures. When they are aligned you should group them.

Step 9: Step 9, Finish:

Select the tail piece and the body. Then align them to be how it is shown in the pictures. After it is aligned then select the tail and move it 10mm into the center or the biplane. Now group all the pieces together and it is finished.