Database modeling question

I have "Airplanes" & "Weapons" (and specialized weapons such as Guns, Bombs and so on that "extend" from Weapons). What I need to do is to describe "Configurations" of weapons, such as:

1. An "Airplane" can have 0 to many "Configurations" (0 means unarmed Airplane)
2. A Configuration is composed by 1 or more Weapons
3. I have to keep track of some attributes for each weapon in a given
   "Configuration". These attributes are not related to the weapon itself
   as they are related to the particular "Configuration" they're being used into.

For example: we have "Airplane" A and weapons B,C and D.

"Airplane" A has 2 "Configurations"

1) B and D
2) B and C

In 1) B has 100 rounds and D has 200 rounds In 2) B has 150 rounds and D has 90 rounds

Now, how can i realize it in a pratical way?