structures (e.g., munition storage bunkers and seismically qualified process and
storage buildings), extremely rocky terrain, soft soil, dense forests, ravines, and
canyons. These special conditions could permit the analyst to reconsider the angle of
impact and the skid length for the aircraft of interest. If, for example, the nearby robust
structure is tall with respect to the facility, the angle of impact might be considerably
larger than the mean value recommended, resulting in a substantially smaller effective
target area. The higher angle of impact may result in a reduced or negligible skid
length, which could also reduce the effective target area. In addition, if the facility is
surrounded by other buildings, the skid distance will not be greater than the largest
distance between these buildings and the facility.
Sample Problem. The following sample problem will take the reader through the steps
described in Section 5.3 of the standard. A facility with three airports within a 22-mile
radius will be considered, as shown in Figure B-4.
FIGURE B-4. Pictorial representation of sample facility and airport locations