The wikipedia article about the TY-90 anti-helicopter missile mentions that China developed the TY-90 specifically as a helicopter-based anti-helicopter missile. This differs from the solution adopted elswhere, namely adapting MANPAD missile for use on helicopters.
While most articles are prolific on the feature that make the missile a anti-helicopter missile (all aspects, dual UV/IR, warhead...) I can't find information on what are the features that make it specifically suited for use in helicopters?
I'm troubled because my understanding is that any fire-and-forget missile could be used on any platform (if size and weight is ok). So why do the Chinese need a purpose-built missile?