This European Standard specifies the technical requirements to minimise the hazards listed in Clause 4 which can arise during the commissioning, the operation and the maintenance of passenger stairs when used as intended, including misuse reasonably foreseeable by the manufacturer, when carried out in accordance with the specifications given by the manufacturer or his authorised representative. It also takes into account some requirements recognised as essential by authorities, aircraft and ground support equipment (GSE) manufacturers as well as airlines and handling agencies.This European Standard applies to:a)self-propelled stairs with seated driver;b)pedestrian controlled stairs;c)towable stairs equipped with powered means, e.g. for height adjustment, stabilisers;d)automatic levelling systems of stairsfor embarking/disembarking of passengers.Powered should also be understood as manual effort stored in springs or hydraulic accumulators, etc., the dangerous action of which can be produced or can continue after the manual effort has ceased or directly applied manual effort for lifting or lowering loads.Those clauses of this standard that can apply may also be used as a guideline for the design of towable stairs without powered means.This European Standard does not establish additional requirements for the following:1)persons falling out of an aircraft with the passenger stairs not in position;2)hazards resulting from a moving stairway (escalator);3)upper deck door access.This part of EN 12312 is not applicable to passenger stairs which are manufactured before the date of publication by CEN of this standard.This part of EN 12312 when used in conjunction with EN 1915-1, EN 1915-2, EN 1915-3 and EN 1915-4 provides the requirements for passenger stairs.