Aircraft hangars shall be in accordance with Sections
412.4.1 through 412.4.6.
412.4.1
Exterior walls.
Exterior walls located less than
30 feet (9144 mm) from lot lines or a public
way shall have a fire-resistance rating not less than
2 hours.
412.4.2
Basements. Where hangars have basements, floors over basements shall be
of Type IA construction and shall be made tight against seepage of water, oil
or vapors. There shall be no opening or communication between basements and the
hangar. Access to basements shall be from outside only.
412.4.3
Floor surface. Floors
shall be graded and drained to prevent water or fuel from remaining on the
floor. Floor drains shall discharge through an oil separator to the sewer or to
an outside vented sump.
Exception: Aircraft hangars with individual
lease spaces not exceeding 2,000 square feet (186
m2) each in which servicing, repairing or washing is
not conducted and fuel is not dispensed shall have floors that are graded
toward the door, but shall not require a separator.
412.4.4
Heating equipment.
Heating equipment shall be placed in another room separated by 2-hour
fire barriers constructed in accordance with Section 707 or
horizontal assemblies constructed in accordance with Section
712, or both. Entrance shall be from the outside or by means of a vestibule
providing a two-doorway separation.
Exceptions:
1. Unit heaters and vented infrared radiant
heating equipment suspended at least 10 feet (3048 mm) above the upper surface
of wings or engine enclosures of the highest aircraft that are permitted to be
housed in the hangar and at least 8 feet (2438 mm) above the floor in shops,
offices and other sections of the hangar communicating with storage or service
areas.
2. A single interior door
shall be allowed, provided the sources of ignition in the appliances are at
least 18 inches (457 mm) above the floor.
412.4.5
Finishing. The process
of "doping," involving use of a volatile flammable solvent, or of painting,
shall be carried on in a separate detached building equipped with automatic
fire-extinguishing equipment in accordance with Section 903.
412.4.6
Fire suppression.
Aircraft hangars shall be provided with a fire suppression system designed in
accordance with NFPA 409, based upon the classification for the hangar given in
Table 412.4.6.
Exception: When a fixed base operator has
separate repair facilities on site, Group II hangars operated by a fixed base
operator used for storage of transient aircraft only shall have a fire
suppression system, but the system is exempt from foam requirements.
TABLE 412.4.6 HANGAR FIRE SUPPRESSION
REQUIREMENTSa, b, c [F]
MAXIMUM SINGLE FIRE AREA, SQ.
FT. |
TYPE OF CONSTRUCTION |
IA |
IB |
IIA |
IIB |
IIIA |
IIIB |
IV |
VA |
VB |
>= 40,001 |
Group I |
Group I |
Group I |
Group I |
Group I |
Group I |
Group I |
Group I |
Group I |
40,000 |
Group II |
Group II |
Group II |
Group II |
Group II |
Group II |
Group II |
Group II |
Group II |
30,000 |
Group III |
Group II |
Group II |
Group II |
Group II |
Group II |
Group II |
Group II |
Group II |
20,000 |
Group III |
Group III |
Group II |
Group II |
Group II |
Group II |
Group II |
Group II |
Group II |
15,000 |
Group III |
Group III |
Group III |
Group II |
Group III |
Group II |
Group III |
Group II |
Group II |
12,000 |
Group III |
Group III |
Group III |
Group III |
Group III |
Group III |
Group III |
Group II |
Group II |
8,000 |
Group III |
Group III |
Group III |
Group III |
Group III |
Group III |
Group III |
Group III |
Group II |
5,000 |
Group III |
Group III |
Group III |
Group III |
Group III |
Group III |
Group III |
Group III |
Group III |
For SI: 1 foot = 304.8 mm, 1 square foot = 0.0929
m2. a. Aircraft hangars with a door
height greater than 28 feet shall be provided with fire suppression for a Group
I hangar regardless of maximum fire area. b. Groups shall be as
classified in accordance with NFPA 409. c. Membrane structures
complying with Section 3102 shall be classified as a Group IV hangar. |
412.4.6.1
Hazardous operations. Any Group III aircraft hangar according to
Table 412.4.6 that contains hazardous operations including, but not limited to,
the following shall be provided with a Group I or II fire suppression system in
accordance with NFPA 409 as applicable:
1.
Doping.
2. Hot work including, but
not limited to, welding, torch cutting and torch soldering.
3. Fuel transfer.
4. Fuel tank repair or maintenance not
including defueled tanks in accordance with NFPA 409, inerted tanks or tanks
that have never been fueled.
5.
Spray finishing operations.
6.
Total fuel capacity of all aircraft within the unsprinklered single
fire area in excess of 1,600 gallons (6057 L).
7. Total fuel capacity of all aircraft within
the maximum single fire area in excess of 7,500 gallons (28
390 L) for a hangar with an automatic sprinkler system in
accordance with Section 903.3.1.1.
412.4.6.2
Separation of maximum single
fire areas. Maximum single fire areas established in
accordance with hangar classification and construction type in Table 412.4.6
shall be separated by 2-hour fire walls constructed in
accordance with Section 706.