Are they different for the rotor heads? Had a uncomfortable situation the other day making an IFR departure. I had just lifted off and tower informs me of a helo off to my left that has me in sight and will remain clear then hands me off to departure. So, I'm watching this helo come pretty darn close to me as I am climbing out and he is right at my altitude and pretty bloody close as I enter the overcast layer (about 1200 overcast). This is in class D, and his rotor is definitely scraping the blottoms of the clouds. Are the cloud clearance requirements different for helos, or was this guy pushing the limits? I wouldn't have called this a near miss, but it was definitely close enough to make me uncomfortable trying to make a single pilot instrument departure.