10 January 2005
including change 3, 13 April 2007
The premise of the design for PMB hangars is that given the combination of the
quantity of dust, and the adequacy and interlocking of dust removal, it is not
possible for dust concentrations to develop that require classification of any
areas of the building. Dust removal and ventilation systems are specifically
designed to remove dust in the combustible particle size range. In addition good
housekeeping practices should be maintained as a supplement to the dust
elimination and ventilation.
Provide the maintenance hangar with flush mounted, floor power ground
receptacles, each with a 19 mm (3/4-inch) diameter ground rod, located at a
minimum of 7.3 m (24 foot) centers across the centerline of the OH space.
Locate additional power ground receptacles around dedicated aircraft parking
areas to facilitate the use of grounding connections. When aircraft are parked
outside of the hangar, provide static ground receptacles on parking aprons.
Resistance to ground for ground power must not exceed 10 ohms maximum,
and for static ground, must not exceed 10,000 ohms in accordance with MIL-
HDBK-274 (AS), Electrical Grounding for Aircraft Safety and with NAVSEA OP5,
Production, Renovation and Shipping
. Connect ground receptacles together with
No. 1/0 AWG minimum bare copper below the hangar floor and connected to the
facility grounding system.
Design fire protection systems in accordance with paragraph 1-10. Exception:
Do not provide foam fire protection systems for facilities containing aircraft that
have their fuel cells removed. Follow the requirements for unfueled aircraft given
in NFPA 409 in this situation.
The type of environmental controls required will depend on the pollution
abatement regulations at the site and the type and quantities of paints used.
Environmental controls can be a major construction and operating cost item;
therefore, an accurate determination of regulations and paints (existing and
proposed) is required prior to design. /2/