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HN September eNewsletter - Foam Fire Suppression Systems in Aircraft Hangars
   HN Newsletter                                                                                       September 2019

In This Issue
ALABAMA

 

Hangar space available at Dothan Regional Airport (DHN)

click here to see listing 

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99,300 +/- SF Hangar for sale at Thomas J. Brumlik Field (8A0)
click here to see listing
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ALASKA
 
5.63 acres for sale at Eagles Roost Airport (AA10)
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ARIZONA
31,000 SF Hangar for sale at Falcon Field (FFZ)
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(2) each 3,840 SF Hangars for sale or lease at Glendale Muni (GEU)
click here to see listing
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CALIFORNIA
   
9,000 SF Hangar for sale at Oakland County International Airport
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T-Hangar for lease at Santa Monica Muni (SMO)
 
  
3,000 SF Hangar for lease at Santa Monica Muni (SMO)
  
  
  
  
  
  
  
  
  
  
  
 
  
 
 
3,600 SF Hangar for lease at Santa Monica Muni (SMO)

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4,153 SF Hangar for sale at McClellan-Palomar (CRQ)
 
550 SF office suite for lease at Hayward Executive (HWD)

1,428 SF hangar for sale/lease at Hayward Executive (HWD)
click here to see listing
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8,000 SF Hangar for lease at Hayward Executive (HWD)
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65,600 SF Hangar for sale at Landells Desert Hot Springs (29CA)
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18,000 SF Hangar for sale at Camarillo Airport (CMA)
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1,428 SF T-Hangar for sale at Van Nuys Airport (VNY)
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COLORADO



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1,088 SF Hangar for sale at Rocky Mountain Metro (BJC)
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 9656 Metro Airport Ave (BJC)

8082 S. Interport Blvd. (APA) 

InterPort Lot FBO 15 (APA) 

Fort Collins-Loveland Muni (FNL) 

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4,200 SF Hangar for sale at Greeley-Weld County Airport (GXY)
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2,500 SF Attached office space for lease at Rocky Mountain Metro Airport (BJC)
   
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To see our properties click below

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FLORIDA

 

61,000 SF state-of-the-art facility at Gainesville Regional (GSV)

click here to see listing

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Eight (8) hangars available up to 22,500 SF for lease at Fort Lauderdale Executive (FXE)
click here to see listing
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6,800 SF Hangar for sale at Massey Ranch Airpark (X50)
click here to see listing
GEORGIA
 
23,578 SF Class A flex building with 14,010 SF Hangar/Warehouse at Smyrna Airport (MQY)
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IDAHO
 
 
3,600 SF Hangar for sale at Boundary County Airport (65S)
click here to see listing
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ILLINOIS
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22,500 SF Hangar for sale at Chicago Executive Airport (PWK)
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MAINE
 

30,000 SF available for lease at Brunswick Executive (BXM)
click here to see listing
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MISSISSIPPI

180,900 SF Hangar for lease with lots of additional space available at Mid Delta Regional (GLH)
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Foam Fire Suppression Systems in Aircraft Hangars

In recent years there has been a discussion among aircraft hangar developers and lessors, aircraft owners and operators, insurance companies, FBOs, trade associations, and fire experts concerning the pros and cons of foam fire suppression systems in aircraft hangars. This article provides an informational and historical overview as well as an outline of the issues central to the conversation, which has become somewhat contentious due to the frequency of accidental or uncommanded discharges of foam systems and the subsequent damage caused to aircraft, other equipment in the hangars, and in at least one case the death of a contractor working inside a hangar.

The National Fire Protection Association (NFPA) is an international nonprofit comprised of more than 50,000 members and 250 technical committees devoted to eliminating injury, death, and property and economic losses due to fire, electrical, and related hazards. Established in 1896 in Quincy, Massachusetts, the group has been instrumental in developing and promulgating codes, training, and certifications for fire protection and mitigation that are considered industry standards.

NFPA 409, Standard on Aircraft Hangars, is one of the primary standards covering fire protection and suppression in hangars. While NFPA has no rule-making authority they are very well-respected in the aviation industry, and when local governments reference its standards in ordinances, they become legal requirements for compliance. Even when not legally required, they are often complied with in order to align with internationally recognized minimum standards (1).

We'll describe the basics of NFPA 409 standards, but first let's look at a brief review of the types of fires and foams in use.

According to the Fire Equipment Manufacturers' Association (FEMA) (2) and NFPA 10, combustion falls into one of the following five classes:


Class A - ordinary materials such as wood, cloth, paper, rubber, and many plastics


 

Class B - flammable liquids such as gasoline and other petroleum products, alcohols, paints, and organic solvents. Gases such as propane and butane are included, but cooking oils and greases are NOT.

 

Class C - energized electrical equipment such as computers, transformers, appliances, and motors. When power is removed, this Class reverts to one of the other Classes


 

Class D - metals such as magnesium, sodium, potassium, lithium, titanium, etc.

 

Class K - fires in cooking oils and grease, including both animal and vegetable fats.

 

 

The first foam used to extinguish a flammable liquid fire was invented in 1902 by Russian engineer and chemist Aleksandr Loran. He was inspired by witnessing very large oil fires near where he taught school in the Azerbaijan city of Baku on the coast of the Caspian Sea, the center of the Russian oil industry at that time (4).

 


Loran's foam consisted of sodium bicarbonate and aluminum sulphate mixed with a small amount of saponin, a surfactant used to stabilize the bubbles by decreasing the surface tension of the water in the mixture. It was thus a chemical foam with the important property of having lower density than either oil or water, allowing it to float on top of the burning liquid.

Since then, numerous mixtures of various types of materials with differing fire-suppression qualities have been used to produce fire-extinguishing foams. Among them were different surfactants, soy protein, fluoroprotein, hydrolyzed protein, stabilizers, and preservatives.

Although introduced in 1902 it wasn't until the 1950s that fire-extinguishing foams were considered as an option for use in aircraft hangars. NFPA had begun issuing what eventually became the NFPA 409 and in early editions the requirement was for deluge-type systems allowing for a choice of plain water or foam. If foam was chosen, a lower sprinkler density was permitted. Foams used then were protein, fluoroprotein, and synthetic (which later evolved into the aqueous film-forming foams or AFFFs).

The deluge systems were discharged by heat-activated devices installed just beneath the roof deck, and sprinkler areas covered up to 15,000 square feet. Hangars with higher roofs were required to have larger systems while smaller hangars with lower roofs were able to use smaller systems.

Over time it became clear that as aircraft grew larger they began to "shadow" the effectiveness of sprinkler systems in the areas beneath their shapes. That is, discharges from roof-mounted sprinklers could not sufficiently reach the areas under the aircraft. So in 1970 the NFPA 409 began requiring supplemental foam in hangars housing the new and larger wide-body aircraft, with oscillating nozzles designed to cover the areas under aircraft wings and fuselages.

The 1985 edition of NFPA 409 eliminated plain-water deluge systems and allowed only foam-water systems for Group I hangars. And now is a good time to mention that although NFPA 409 requires fire suppression systems in all hangars, not all hangars require the same level of protection.

Hangars are placed into four groups based on their internal area and construction type for the purpose of fire protection/suppression (5):

 

Group I hangars are those that have either a door height greater than 28', a single fire area greater than 40,000 square feet, or be capable of housing an aircraft with a tail height over 28'.


 

Group II hangars have doors up to 28' in height with single fire areas ranging from 5,000 to 40,000 square feet based on construction type.


 

Group III hangars must have doors 28' or less and a single fire area up to 30,000 square feet based on construction type.


 

Group IV hangars are membrane-covered rigid steel frame structure either 12,000 square feet housing fueled or unfueled aircraft, or less than 12,000 square feet.


 

 

As would be expected, the Groups have varying fire protection requirements and a comprehensive description of those is beyond the scope of this article. The main discussion of risks versus benefits of foam fire suppression systems centers on Group I and II hangars, where the greatest fire threat is a fuel spill in close proximity to a source of ignition, and where there seems to be a disconnect between the NFPA 409 standards and actual fire risk as we'll see below.

Most foams in use today consist of three main ingredients: water (fresh, brackish, or seawater), foam concentrate whose composition varies by application and manufacturer, and air. Foam systems are designed to mix the ingredients together just prior to discharge in pre-determined ratios specific to the application or structure. Foams also have the property of expansion ratio, those being Low-, Medium-, and High-expansion, depending on the ratio of the ingredients and the amount of aeration. Low-expansion foam is aerated to a ratio of between 2:1 and 20:1, medium-expansion foam ranges from 20:1 to 200:1, and high-expansion is above 200:1. So for example, a 20:1 ratio means that one gallon of foam solution would fill a 20 gallon container after aeration and expansion.

Foams are generally classified as Class A and Class B which, as their names imply, refer directly to the types of fires for which they are used to extinguish - Class A fires and Class B fires, respectively. Typically, hangar foam systems utilize High-expansion Class B foams which are best suited for enclosed spaces. Class B foams fall into two subtypes: Synthetic and Protein.

The more widely-used Synthetic foams employ synthetic surfactants that provide better flow and spreading characteristics for faster flame knockdown when applied to a hydrocarbon-based liquid such as Jet-A. Alcohol-Resistant foams form a protective polymer layer between the foam and a burning liquid containing alcohols, preventing breakdown of the foam. These are appropriate when the liquid contains alcohol-forming oxygenates, often added to fuels.

Here is a list of the common fire suppression foams in use today (not all are used in aviation applications):

 

- Aqueous Film-Forming Foam (AFFF)

- Alcohol-Resistant (AR-AFFF)

- Class A Foam Concentrate

- Synthetic (Detergent) types

- Wetting Agent

- Fluoroprotein

- Protein

- Film-Forming Fluoroprotein


 

More information on the foams is available on the CHEMGUARD website (3).

Foams work in hangars because their physical properties cause them to float on top of but cling to burning fuel with a smothering action that cuts off oxygen, provides cooling to the fuel, and suppresses fuel vaporization.

As mentioned at the outset, the conversation about the requirements for fire protection, particularly foam fire suppression systems, is that on the one hand they work very well when needed, helping to protect high-value assets and can be legally required depending on local jurisdictions and the type of hangar and the activity taking place within it.

On the other hand they can and do discharge accidentally or inadvertently with distressing frequency, causing expensive loss or damage to aircraft and other equipment in the hangar, loss of business due to downtime and arranging substitute aircraft, and negatively impacting operations. Environmental concerns may also emerge as a result of such discharges.

Reasons for false activations include improper system design, lack of proper commissioning, lack of proper testing, and inadequate maintenance. Large hangars call for the design of suppression systems on a scale with which an engineer may not be familiar. In the event at Eglin Air Force Base in January, 2014, temperatures of 30o F caused part of the system to freeze, leading to a buildup of pressure that eventually activated the discharge of foam. The foam rose to 17', engulfing and eventually suffocating a maintenance contractor.

Claims data over the past decade analyzed by insurance provider Global Aerospace indicated that there was not one instance of an intentional discharge in response to an actual fire. Every claim submitted was for an accidental or inadvertent discharge, and the frequency and severity of claims increased since 2013 (7). Claim values vary widely but one event alone in 2018 resulted in costs greater than $25 million.

To be fair, hangar fires do occur but only rarely and most do not involve aircraft fuel, and tend to occur in less sophisticated hangar environments. Some experts contend that fire codes and standards have not kept up with technological and operational advances and are disconnected from the risk attributable to the history of actual fire losses. Some observers believe that the sophistication of Group I and II operators makes automatic fire suppression questionable. They propose manual activation in such environments, after human confirmation of a fire instead of relying on too-sensitive or faulty sensors.

For many experts in the industry, the conversation has progressed from casual debate to open advocacy for change to the standards.

Mercer Dye, Founder of Dye Aviation Facility Architecture, LLC, is a backup member of the NFPA 409 Technical Committee. He has strong and well-informed opinions on the topic and has advocated for change for more than ten years. "My goal is to eliminate foam fire suppression in Group II hangars," he has stated.

The National Air Transport Association (NATA) is advocating for a reexamination and possible modification of the NFPA requirements for hangars to that of a risk-based approach. In fact, NATA has recently signed a sponsored research agreement with the University of Maryland's Department of Fire Protection Engineering to analyze existing data on the causes, hazards, and associated costs of accidental discharges. The research will also examine the rationale for the requirement of such systems in the NFPA 409.

"NATA members have repeatedly voiced concern that the cost of installing these foam systems dramatically increases the expense of new hangars while providing limited risk mitigation due to the low instance of hangar fires," stated NATA President and CEO Gary Dempsey.

We will continue to track this issue and keep you apprised of the latest information. Also keep an eye on our blog as we'll cover it there as well.


Mike Straka, PhD
HN Contributing Author & Technical Support
Executive Director, Colorado Aviation Business Association

Sources

1. Challenges of Aircraft Hangar Fire Protection - The Development and Use of a Modern Standard. Michael E. Aaron, P.E. Society of Professional Fire Engineers website, Q1 2013 Issue. 
2. Fire Equipment Manufacturers' Association website. https://www.femalifesafety.org/types-of-fires.html

3. General Foam Information Data Sheet. Available on the CHEMGUARD Specialty Chemicals and Equipment website.
4. Firefighting Foam. Wikipedia website. 
5. Airplane Hangar Fire Suppression Systems - An Essential Guide. Aaron Johnson. Quick Response Fire Supply blog, January 8, 2019. 
6. Pros and Cons of Hangar Foam Fire Suppression Systems. Global Aerospace article, June 27, 2019.
7. Hangar Foam Fire Suppression Systems - More Harm Than Good? Nick Methven. Global Aerospace White Paper.
8. NATA Teams with the University of Maryland to Tackle Foam Fire Suppression Discharges in Aircraft Hangars. Press Release. National Air Transport Association website, July 8, 2019.
9. Photo Credit: U.S. Senior Airman Gina Chiaverotti. A Fire Protection Specialist takes a sample of high-expansion foam for testing. Foam Fire Suppression System Test at Moody Air Force Base, Georgia. Public domain image.

SIGNATURE FLIGHT SUPPORT LISTINGS

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FEATURED AIRPORT DEVELOPMENT LAND AND HANGARS 


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Future Development for 2018-2019 and newly renovated office space available
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40 acres for lease at Hagerstown Regional Airport
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Available Hangars, buildings, and development lots
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NEW PROPERTIES



15,000 SF Corporate Hangar for sale at Driggs-Reed Memorial Airport (DIJ)

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Secure your custom Aviation Facility at Austin's new private airport
Greenport International Airport (GIA)

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26,100 SF Hangar space for lease and transient space at Jacqueline Cochran Regional (TRM)

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2,000 SF Hangar space for lease at Centennial Airport (APA)
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780 SF hangar space available for lease at Rocky Mountain Metro (BJC)
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Beautiful 2,800 SF hangar with a total of 6,000 SF finished space including 2 pad sites and 7 parcels for development at Erie Muni (EIK)
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350,000 SF of brand new aviation development at Falcon Field (FFZ)
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4,920 SF Hangar with 13,365 SF Office/Shop space for sale at Phoenix Deer Valley Airport (DVT)
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SOLD / LEASED
 PROPERTIES
Parkland Estates Airpark home for sale (7CO0)
SOLD

933 SF Hangar for sale at Santa Fe Muni (SAF)
SOLD

1,600 SF Hangar for sale at Morey Field (C29)
SOLD

1,283 SF Hangar for sale at Durango-La Plata County Airport (DRO)
SOLD

9,000 SF Hangar for sale at Naples Muni (APF)
SOLD

15,032 SF Hangar for sale at Boeing Field (BFI)
SOLD

31,017 SF Hangar for sale at Morristown Muni (MMU)
SOLD

7,500 SF Hangar for lease at Fort Worth Meacham Int'l. (FTW)
LEASED

18,000 SF Hangar for lease at Fort Worth Meacham Int'l. (FTW)
LEASED

15,904 SF Hangar for sale at West Houston Airport (IWS)
SOLD

25,300 SF Hangar for lease at Daugherty Field (LGB)
LEASED

6,000 SF Hangar for sale at Minden-Tahoe Airport (MEV)
SOLD
________________
NEVADA
 
FIRE SALE PRICE
33,800 SF Hangar for sale at North Las Vegas Airport (VGT)


RE/MAX Realty Affiliates
 
24,762 SF Hangar with 4,238 SF office for sale at Minden Tahoe (MEV)

  
Accepting reservations for the first six of 18 new hangars at Carson City Airport(CXP)
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12,900 SF Hangar for lease at McCarran International Airport (LAS)
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NEW HAMPSHIRE

 
Newly available heated, high tail hangar space for multiple jets including G650 and Global at Portsmouth International Airport (PSM)
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NEW YORK
Custom Build-to-Suit Hangars available for lease at Republic Airport (FRG)

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31,200 SF Hangar space for lease at Republic Airport (FRG)
NORTH CAROLINA

Unique Mountain Home, Land and Airstrip for sale Sossamon Field (57NC)
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OREGON
 
96,000 SF of heated hangar space available for lease at Portland-Hillsboro (HIO)
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100% leased corporate Hangar/Office/Shop for sale at Medford Airport (MFR)
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Transient Space for lease at Portland-Hillsboro (HIO)
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30,000 SF Hangar for lease at Southwest Oregon Regional Airport (OTH)

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Picture not available at this time

1,800 SF Hangar for sale at Mahlon
Sweet Field (EUG)
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PENNSYLVANIA
 
 
 
Privately owned, public use 308 acre Spring Hill Airport for sale (70N)
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8,800 SF Hangar with office and shop space for sale at Harrisburg International (MDT)
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SOUTH CAROLINA
 
17,622 SF Hangar for lease at Spartanburg Downtown Memorial (SPA)
TENNESSEE
 
1.16 acres for sale at Collegedale Muni (FGU)
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TEXAS


15,400 SF Hangar for lease at San Antonio International (SAT)

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Own the land and 3,750 SF Hangar at Parker County Airport (WEA)
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Fabulous Airpark Hangar and home on 1-acre lot at Propwash Airport (16X)
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WASHINGTON


Class A Hangar/Office space for lease at Boeing Field (BFI)
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To see our properties at Bowerman Field click below
 

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HANGAR NETWORK LLC | 855-942-6427 | info@hangarnetwork.com | http://www.hangarnetwork.com
HANGAR NETWORK LLC, 2221 E. Arapahoe Road, Suite 2192, Centennial, CO 80161

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