From the Futaba FAQ site:

I am building a small model. Should I leave the antenna hanging out the back of the plane or wrap/fold/cut it?
Never shorten your antenna by cutting down its physical length or by folding it back upon itself. Always allow the antenna to extend its full length, even if it means having a 'tail' hanging out the back of your model. You might also consider running it out the wingtip rather than down the fuselage.

No matter what ANYONE tells you, if you double back, fold or curl your antenna you are detuning it and decreasing your effective range. You may still have ENOUGH range to operate your model or you may not, it's your plane. This is also a fact.
I base my information upon my Electrical Engineering degree, 30 years experience in full scale aircraft avionics and 25 years r/c flying. Take your choice. It may work and it may not, let us know.