Introduction - std30140042

DOE-STD-3014-96

each method is needed. Neither this standard nor the modeling and data technical

support documents contain site-specific information; rather, they provide guidance on

what site-specific information is necessary and how to develop it.

Aircraft crash frequencies are estimated using a "four-factor formula" which considers

(1) the number of operations, (2) the probability that an aircraft will crash, (3) given a

crash, the probability that the aircraft crashes into a 1-square-mile area where the facility

is located, and (4) the size of the facility. In this standard, the four-factor formula is

implemented in two different ways, depending on the flight phase:

For near-airport activities, which consist of takeoffs (i=1) and landings (i=3), the

four-factor formula is implemented through a combination of site-specific

information and data obtained by the user of the standard, and a set of tables

(whose origins are discussed in Reference 2) provided in Appendix B of this

standard.

For nonairport activities (i=2), DOE site-specific values, as well as reasonable

estimates applicable throughout the continental United States, for the expected

number of crashes per square mile per year in the vicinity of the sites (i.e., the

value of the product NPf(x,y)) are provided in Appendix B of this standard; the

four-factor formula is implemented by combining these with the facility effective

areas to assess frequencies.

Mathematically, the four-factor formula is:

Nijk

Pijk

fijk(x,y)

Aij

(5-1)

i, j,k

where:

estimated annual aircraft crash impact frequency for the facility of

interest (no./y);