UFC 3 -520-01
June 10, 2002
Wherever possible, do not locate electrical distribution or utilization equipment
in zones classified as hazardous. Locate main distribution panels, metering equipment,
and similar electrical equipment in a room separate from the aircraft storage and
servicing areas. This electrical equipment room must be protected by a partition having
at least a 1 -hour fire resistance rating. The partition must not be penetrated except by
electrical raceways, which must be protected by approved sealing methods that
maintain the same fire resistance as the partition.
Corrosion control hangars are designed to provide space and equipment for
the corrosion control processing of aircraft. Functions performed in a corrosion control
hangar can include deicing; limited detergent washing and rinsing; paint stripping;
corrosion removal; protective coating application and painting; and finish curing and
drying. Locate electrical utilization equipment in corrosion control hangars to facilitate
the various functions that might be performed. Electrical installations in the hangar
area, paint and chemical mixing rooms, paint equipment cleaning room, and paint
storage room must meet the requirements specified in NEC Articles 500 and 501 (2002
Edition) for the specific hazardous (classified) location. Apply NFPA 33, Spray
Applications Using Flammable or Combustible Materials, in hangars where the rate of
spray paint application exceeds 0.9464 liters (1 quart) per hour or the cumulative
application of more than 3.7854 liters (1 gallon) over an eight-hour period.
Fire protection criteria for hangars are provided in Air Force ETL 98-7, Fire
Protection Engineering Criteria New Aircraft Facilities, and ETL 98-8, Fire Protection
Engineering Criteria Existing Aircraft Facilities. Wherever deluge sprinkler protection
is provided, electrical equipment in the hangar bay must be waterproof to prevent
equipment damage in the event of testing or accidental discharge of the deluge system.
Refer to paragraph F -15.5 for lighting design criteria.
Refer to paragraph 6 -4 for design criteria for convenience outlets and
receptacles. Flexible cords for aircraft energizers, ground support equipment, and
mobile servicing equipment must be suitable for the type of service and approved for
extra-hard usage, and must include an equipment grounding conductor. All outlets in a
Class I, Division 2 location in the aircraft servicing area must be rated for such use.
HIGH-ALTITUDE ELECTROMAGNETIC PULSE (HEMP) AND TEMPEST
TEMPEST is a program to develop methods of preventing the compromise of
government and military information by reducing or eliminating unintended electric or
electromagnetic (EM) radiation emanations from electronic equipment. The TEMPEST
approach is nearly the opposite of the HEMP event. TEMPEST is the unclassified name
for the studies and investigation of compromising emanations. Equipment within the
facility can be the source of EM waves and stray currents/voltages with characteristics
that are related to the information content of signals being processed. Thus, HEMP and
TEMPEST protective measures must each control EM energy, the former protecting