ISO 1021:1980

Aircraft — Engine nacelle fire extinguisher apertures and doors

Relates to openings for the insertion of the nozzles of ground fire extinguishing equipment. If one or more openings are provided, they shall be either round or square in shape and of the following dimensions: Round; the diameter shall be from 1OO mm minimum to 13O mm maximum; Square; the sides of the squares shall be from 1OO mm minimum to 13O mm maximum.