sentences:  Maintenance of oxygen bottles, crew and passenger oxygen masks together with Passenger Service Units (PSU) is responsibility of Oxygen Workshop which is a part of Instrument Workshop.Electric Workshop performs maintenance of various control boxes, relays, components from distribution system of electrical power, electrical starters and generators, electrical harnesses, fire detection sensors, batteries and other electrical units.Pneumatic Workshop is in charge of components from pneumatic, air-conditioning, pressurization, anti-icing, de-icing, engine bleed and engine starting systems.