NFPA 409 – Hangar Foam Fire Suppression Initiative

The National Fire Protection Association (NFPA) 409: Standard on Aircraft Hangars is the primary standard for hangar fire protection and is referenced by the international building code (IBC), the international fire code (IFC), and state and local statutes, ordinances and regulations. NFPA 409 requires most modern general aviation hangars to have automatic foam fire suppression systems installed.
NATA members have repeatedly expressed concern that the cost of installing these foam systems dramatically increases the cost of new hangars, while providing limited risk mitigation due to the low incidence of hangar fires. Additionally, the risk of accidental discharge of these systems is high and such discharges include significant costs related to clean-up and aircraft damage.
The typical foam system installation costs for a general aviation hangar range between $200,000-$500,000. Initial research indicates that multiple accidental hangar foam discharges occur every year, causing more than $100 million in aircraft damage over the last 10 years. The estimated clean-up and recovery costs per accidental discharge are between approximately $20,000-$40,000 per event.
NATA Initiative
NATA launched this initiative in 2018 to change NFPA 409 to reduce the burden on aviation businesses from the existing requirements for foam fire suppression systems in aircraft hangars. This initiative seeks to leverage the broad support across our industry to develop the financial resources, technical and business expertise, and grass-roots action necessary to create change through the NFPA Technical Committee. In addition to a reduction in the requirements for foam systems in aircraft hangars, this initiative seeks to develop and publish resources for use by the industry, including a guide for interacting with local fire officials when constructing new hangars.
What are the goals of this initiative?
1. Quantitatively define the risk of the type of fires that foam systems are designed to mitigate (pooled fuel fires in hangars)
2. Define the true cost of foam fire suppression systems
a. Installation
b. Maintenance
c. Accidental discharge (clean-up, aircraft damage)
3. Explore the life safety issues arising from the use of foam in hangars
4. Propose changes to NFPA, considering items 1-3, that align the standard with the actual risk of fire
What is the timeline for this initiative?
The revision cycle for the standard is underway and the First Draft Meeting has been completed (see insert). NATA’s proposal and industry comments will be due by November 14, 2019. Technical committee review and internal NFPA processes will occur during late 2019 through mid-2021 and the next edition of NFPA will be published in early 2021.

In July 2019, NATA and the University of Maryland signed a sponsored research agreement in an effort to review the causes, hazards, and associated costs of accidental discharges of foam fire suppression systems. The project will also address high-expansion and low-expansion foam systems, in addition to determining the rationale for the requirement of foam systems included in NFPA 409 for aircraft hangars.