The fire protection design should be in accordance with the latest edition of UFC-3-600-01.
Water supplies for aircraft hangars should also be in accordance with the latest edition of UFC-3-
Fire Suppression System
The fire suppression system for all aircraft maintenance hangars containing fueled aircraft shall
consist of an overhead wet pipe sprinkler system with low temperature, quick response
sprinklers, and a low-level AFFF system that shall be designed in accordance with NFPA 409.
The overhead system shall be closed head, water only sprinklers. A pre-action system shall only
be allowed where there is a risk of sprinkler pipes freezing. The system shall activate
automatically. The low-level system shall consist of a system of nozzles located in the floor
trench drains. Activation of the low-level shall be manual and automatic. Actuation of a manual
releasing station, optical detector or the overhead sprinkler system shall release the low-level
Provide apron and hangar floor drainage in accordance with NFPA 409. Floor drains in aircraft
storage and service areas should be trench-type drains designed with sufficient capacity to
prevent buildup of flammable/combustible liquids and water over the drain inlet when all fire
protection systems and hose streams are discharging at the design rate. Maximum trench spacing
will be dictated by the spray pattern of the trench nozzles, manufacturer's nozzle data should be
consulted for this information. The trench must be of adequate size to contain a 6 inch pipe
(approximately) with fittings for the AFFF trench system. The width and depth of all trench
drains should be calculated accordingly. In addition, the trench drains should have sufficient
room to accommodate mounting the floor-level AFFF solution system piping and nozzles where
provided. Floor drains should be in accordance with appropriate facility plates and Figure 3,
Trench Drain Detail and Figure 4, Trench Plate Arrangement.
Provide non-combustible draft curtains to separate the hangar bay roof area into individual
sections not exceeding 697 square meters (7,500 square feet) in area. Draft curtains should be
constructed and installed in accordance with NFPA 409.
O1/O2 Level Spaces
Automatic, wet-pipe sprinkler system should be provided in areas of the hangar facility not
requiring AFFF sprinkler protection.
Fire Alarm Systems
Provide manual and automatic building fire alarm system reporting to the base-wide system.