Your question depends heavily on where youre at, my man. Where im at, you could be standing in a clearing on a 10 foot ladder, smoking a blunt and holding a 1 foot tall weed plant above your head like its fucking baby Simba, and a CAMP (Campaign Against Marijuana Produciton) helicopter 50 feet away wouldn't even look twice.
I have been buzzed by choppers from CAMP maybe a dozen times while standing in my 25 plant crop, smoking a joint and waving at them. Once, the fuckin copter was so close we could paractically see the pilot's facial hair, so me and my two friends mooned that mother effer and he flew away.
Anyway, im baked and im getting side tracked... In short, you should be fine my friend. I don't know about the laws in your area, but I feel fairly confident that no matter where you live, no law enforcement agency would be wasting money on eradicating a one plant crop spotted by a helicopter. Hope all goes well for you! Good luck with the grow peace!