15 Oct 97
3.11 Heating Equipment.
3.11.1 Heating equipment will be in accordance with the applicable provisions of NFPA 90A,
Standard for the Installation of Air Conditioning and Ventilating Systems.
3.11.2 No heater employing an open flame or glowing element will be installed in helicopter
hangar bay areas.
3.11.3 Heating systems fired with gas, liquid, or solid fuels which serve aircraft maintenance and
storage areas will be located in a detached building or in a room separated from the hangar by
minimum 1-hour fire-rated construction.
3.12 Electrical Systems.
3.12.1 Electrical services will be installed in accordance with Article 513 of NFPA 70, National
3.12.2 Floor grounding receptacles will be provided for removal of static electrical accumulations
on aircraft while aircraft are stored or undergoing servicing inside the facility.
3.13 Fire Protection Systems and Equipment.
3.13.1 Automatic sprinkler protection, consisting of one of the following types of systems, will
be provided in helicopter hangar bays in accordance with the requirements specified in this ETL:
a. Wet-pipe foam-water systems utilizing aqueous film-forming foam (AFFF).
b. Preaction foam-water systems utilizing AFFF.
c. Water-only wet-pipe systems utilizing Early Suppression Fast Response (ESFR) sprinklers
operating at a minimum discharge pressure of 345 kPa (50 psi).
3.13.2 Conventional automatic sprinkler protection, utilizing water (only) and standard
sprinklers, will be provided for offices, shops, storage and similar areas adjoining or adjacent to
helicopter hangar bays. Hazard classifications and corresponding sprinkler design requirements
will be in accordance with MIL-HDBK-1008C.
3.13.3 Manual fire alarm (evacuation) systems will be provided in accordance with NFPA 72,
National Fire Alarm Code.