This European Standard specifies the technical requirements to minimise the hazards listed in Clause 4 which can arise during the commissioning, operation and maintenance of maintenance stairs and platforms when carried out in accordance with the specifications given by the manufacturer or his authorised representative. It also takes into account some performance requirements recognised as essential by authorities, aircraft and ground support equipment (GSE) manufacturers as well as airlines and maintenance and handling agencies.This European Standard applies to:-self-propelled maintenance stairs and platforms;-towable maintenance stairs and platforms equipped with powered means, e.g. for height adjustment, stabilizers,designed for aircraft maintenance purposes including access to the aircraft (Examples see Annex A).NOTE 1Powered should be also 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.NOTE 2Those clauses of this European Standard that can apply may also be used as a guideline for the design of towable maintenance stairs and platforms without powered means.This European Standard does not apply to:-maintenance docks either fixed to the ground or moveable only for docking procedure.This European Standard does not establish requirements for noise and vibration.Noise and vibration are dealt with respectively in EN 1915-4 and EN 1915-3.This European Standard does not deal with hazards in respect to a standard automotive chassis and from other vehicles on the apron.This Part of EN 12312 is not applicable to maintenance stairs and platforms which are manufactured before the date of publication of this standard by CEN.This part of EN 12312 is intended to be used in conjunction with EN 1915-1, EN 1915-2, EN 1915-3 (for vehicles) and EN 1915-4.