very common in china, no matter old small town resident (up to 8 storey tall) or larger 3rd tie city condominium, the air-con installer and repair worker has no proper access path. there is a safety line but either the line is held on by two or 3-person within the worker's team or loop around the nearest door (loop thru the gap between the door and the door frame.
Installation of new outdoor unit is ok, but repair of the outdoor unit (or even the indoor fan-coil) don't bother as the skill level is worst than our ah neh.
Any of the ITE guys willing to go over China to start a company just to repair and service residential air-con (or tech the skill there) may able to earn big bucks......but you need to be very street smart as the china locals are fucker if they know you are foreigner starting business there.