Modular Airborne FireFighting System

A MAFFS-equipped C-130 Hercules from the 302nd Airlift Wing makes a water drop over New Mexico during a training exercise, May 2007

The Modular Airborne FireFighting System (MAFFS) is a self-contained unit used for aerial firefighting that can be loaded onto a Lockheed C-130 Hercules, a military cargo transport, which then allows the aircraft to be used as an air tanker against wildfires.[1] This allows the U.S. Forest Service (USFS) to use military aircraft from the Air National Guard and Air Force Reserve to serve as an emergency backup resource to the civilian air tanker fleet.[1][2]


A MAFFS I unit about to be loaded into a C-130 in North Carolina in 2008.

Congress established the MAFFS program after the 1970 Laguna Fire overwhelmed the existing aviation firefighting resources.[2] The USFS was directed to develop a program in cooperation with the Air National Guard and Air Force Reserve to produce the equipment, training and operational procedures to integrate military air tankers into the national response system. The Engineered Systems Division of FMC Corporation (Santa Clara, CA) was contracted to design, build and test the modular tank system that would enable a standard C-130 to be quickly converted into a tanker. Initial flight tests with a prototype two-tank installation began in July 1971.[3] Subsequent systems were fabricated by Aero Union of Chico, California.

The MAFFS consists of a series of five pressurized fire retardant tanks with a total capacity of 2,700 US gallons (10,000 l; 2,200 imp gal) and associated equipment which is palletized and carried in the aircraft's cargo bay.[2] In addition to the retardant tanks, each module contains a pressure tank where compressed air is stored at 82.7 bar (1200 psi). The control module includes the master control panel, the loadmaster's seat, and discharge valves. An air compressor module provides air pressure for charging the system; it stays at the airtanker base during air operations and is used to recharge the system between runs. Each unit weighs about 11,000 pounds (5,000 kg). It can be installed in any C-130-E or -H equipped with the USAF 463L cargo-handling system.[1]

Air tankers are categorized by their retardant capacity, and although the MAFFS capacity is just under 3,000 US gallons (11,000 l; 2,500 imp gal), a MAFFS C-130 is considered a Type 1 air tanker, which is the largest class.[4][5] Retardant exits through two tubes which extend out the plane's aft cargo bay doors. The system can disperse all 10,220 L (2,700 gal) in five seconds over a fire, producing a fire line that is 60 feet (18 m) wide and a 400 m (quarter mile) long. It can then be reloaded in eight minutes.[1][2] Maffs Corp. is a combination of two leading aftermarket support companies, United Aeronautical Corporation and Blue Aerospace. As an owner of some applicable intellectual property, tooling, and assets related to the design and manufacturing of retardant delivery systems including MAFFS I and II and RADS II, Maffs Corp assists with the service and support of existing systems as well as the design and construction of new aerial tanking and effluent delivery systems.[6][7]


A MAFFS II on display, Channel Islands Air Guard Station, California, May 2008
A MAFFS-II being tested; the discharge pipes in the paratroop drop doors can be seen.

Aero Union, under contract to the USFS, has developed an improved version of the system, known as the MAFFS II. The new system has a capacity of up to 3,000 US gallons (11,000 l; 2,500 imp gal), replacing the five retardant tanks with one large tank, and has two on-board air compressors. The original MAFFS has to be pressurized by a compressor on the ground as a part of the loading process. The ability to pressurize the system in the air cuts turn-around time significantly.[8] The new system discharges the retardant through a special plug in the paratroop drop door on the side of the aircraft, rather than requiring the cargo ramp door to be opened; this allows the aircraft to remain pressurized during the drop sequence.[9] Far more significantly, the cargo ramp and door can remain closed, cutting drag considerably, and thereby allowing a greater performance margin than available with MAFFS I.

Aero Union delivered the first production unit to the USFS in July 2007, and was flight tested during August.[9] MAFFS II was used for the first time on a fire in July 2008, when a crew from the 302d Airlift Wing launched from McClellan Tanker Base in California on an operational test using a C-130H.