#Jettison environmental update

If an aircraft lands at more than its maximum allowable weight, it might suffer structural damage or even break apart on landing.Īs jets began flying in the US in the late 1950s and early 1960s, the FAA rule in effect at the time mandated that if the ratio between an aircraft's maximum structural takeoff weight and its maximum structural landing weight was greater than 1.05, the aircraft had to have a fuel-dump system installed. If a flight takes off at the maximum takeoff weight and then must land well before its destination, even returning immediately after takeoff to the departure airport (for example, because of mechanical problems or a passenger medical problem), it will contain more fuel than was intended for landing. It is the abnormal, non-routine flight where landing weight can be a problem. This allows an aircraft on a normal, routine flight to take off at the higher weight, consume fuel en route, and arrive at a lower weight. Mount Rose Scientific, LLC acquired all rights to FJSIM from Continuum Dynamics, Inc.Ĭontact Us for more information or to arrange for licensing FJSIM.Aircraft fuel dump Weight issues Īircraft have two major types of weight limits: the maximum takeoff weight and the maximum structural landing weight, with the maximum structural landing weight almost always being the lower of the two.

#Jettison environmental update

Modeling aerially applied sprays: An update to AGDISP model development. Modification of droplet evaporation in the simulation of fine droplet motion using AGDISP. Technical advances in modeling aerially applied sprays.

Low-temperature vaporization of JP-4 and JP-8 fuel droplets.

268-272, 1996.Liquid Atomization and Spray Systems Polymeropoulos, “Dropsize Distribution from Large Orifices,” ILASS-Americas 9th Annual Conference on San Francisco, CA, pp. Quackenbush, Teske, and Polymeropoulos “A Model for Assessing Fuel Jettisoning Effects”, Atmospheric Environment, Vol.The technical basis of FJSIM is summarized in: Heavy black line indicates aircraft path during jettison. Figure 3: Surface deposition plots can be shown as a planview isopleth (left) or colormap plot (right). Figure 2: FJSIM Main Screen w/ meteorology window.(note: A variety of metric and English units can be selected). Separate plots of drop size distribution and time aloft are also provided, as is surface evaporation (a result which answers “How long will the fuel remain on the surface”). Plots of surface deposition are available and provide the approximate location, areal extent, and concentrations of material reaching the ground (Figure 3). Air Force aircraft, and other aircraft can be easily added. A main screen (Figure 2) contains nearly all U.S. The model features numerous input/output elements and displays. Experimentally determined drop size distribution.The principal components of the FJSIM model are: Figure 1: Fixed and rotary wing platforms modeled by FJSIM. This Windows-based model lets users estimate the location, total mass, volume, and areal extent of the groundfall from actual jettison events and planned operations, and can assist in reviewing and developing fuel jettison policies. FJSIM combines a detailed, experimentally-verified fuel evaporation model, ambient meteorological conditions and individual aircraft characteristics to yield a demonstrator model for fuel jettisoning. Realizing this, the Air Force embarked on the FJSIM research effort to accurately predict surface concentrations of JP-8 in order to protect people and resources on the ground. Air Force conversion from JP-4 jet fuel to the less-volatile JP-8 in the 1990s substantially increases the chances of significant JP-8 groundfall from jettisoned fuel. Military pilots are sometimes required to jettison fuel to land safely. The fuel jettisoning simulation model FJSIM provides a key tool for evaluating the health and environmental impact of fuel jettisoning events from fixed and rotary wing aircraft. Fuel Jettisoning SIMulation (FJSIM) for Prediction of Groundfallįuel jettisoned from aircraft in flight may pose a health and environmental hazard at the surface.