# Need help calculating the odds on a falling object.

1. Sep 22, 2011

### freerangequark

I am working on a product development project for an aircraft application.

I need a rough calculation of the odds of a particular part falling off a particular aircraft during a particular emergency of hitting a person(s) on the ground. This is to cover the contiguous United States.

Variables I have:

1. Population density of the contiguous United States, 79.6 people per square mile (79.6 people per 27,878,400 sq. ft.)

2. Land area of the contiguous United States, 3,043,615 sq miles (84,851,116,416,000 sq. ft.)

3. Average area per person, 3.7 sq. ft.

4. Max. size of the falling part. 3' X 9' (27 sq. ft.)

5. Frequency of the emergency. 1 instance per 96,429 flight hours

How can I determine the chances per occurance (or per flight hour) of this falling part hitting a person(s)?

I realize there are many other variables to consider such as the population density of a given geographic area, but all I need is an average.

Any help is greatly appreciated.

Thanks,
Glenn

Last edited: Sep 22, 2011