Might be a stupid question…are you putting the Velcro on the canopy of the fuselage?Fuzzy side of Velcro
I use the fuzzy side of Velcro. It works really well and will not scratch paint. I got the "industrial" label stuff from Home Depot. The Velcro part is the same but the adhesive is super strong. Make sure you put it where you want it because it is not coming off without significant effort. It lasts quite well. Over 500 hours on mine to date.