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 914.8.3.
Exception: Where 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 shall be exempt from foam requirements.
HANGAR FIRE SUPPRESSION REQUIREMENTSa,b,c
| MAXIMUM SINGLE FIRE AREA (square feet) | CALIFORNIA BUILDING CODE 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 square foot = 0.0929 m2, 1 foot = 304.8 mm.
- 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.
- Groups shall be as classified in accordance with NFPA 409.
- Membrane structures complying with Section 3102 of the California Building Code shall be classified as a Group IV hangar.
Any Group III aircraft hangar in accordance with Table 914.8.3 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:
- Doping.
- Hot work including, but not limited to, welding, torch cutting and torch soldering.
- Fuel transfer.
- Fuel tank repair or maintenance not including defueled tanks in accordance with NFPA 409, inerted tanks or tanks that have never been fueled.
- Spray finishing operations.
- Total fuel capacity of all aircraft within the unsprinklered single fire area in excess of 1,600 gallons (6057 L).
- Total fuel capacity of all aircraft within the maximum single fire area in excess of 7,500 gallons (28 390 L) for a hangar equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1.