Multiply the ordinate of this curve (i.e., mass per unit length) by the following,
total weight of the subject aircraft;
total weight of the similar class aircraft;
length of the subject aircraft;
length of the similar class aircraft.
Make the necessary adjustments to this curve based on the known differences
between the weights of major components and segments of the two aircraft, but
keep the total weight of the subject aircraft Wa unchanged.
If Pc (fuselage buckling or crushing load) cannot be obtained from the aircraft
manufacturer, it can be estimated as follows:
From published literature, obtain the Pc distribution and the crush interface area
(A) distribution of a similar category or subcategory of aircraft, the shape and
configuration of which have some similarity to the subject aircraft.
Multiply the ordinate of this curve (i.e., crushing strength) by the following factor,
which varies with the distance, x, from the nose to the crush interface: