MAFFS II
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 3,400 US gallons (13,000 l; 2,800 imp gal), replacing the five retardant tanks with one large tank, and has an on-board air compressor. 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. 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. 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. 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.
Read more about this topic: Modular Airborne Fire Fighting System, Development