Portal:Civil Aeronautics Board

“ If the fuel lines are moved inboard toward the center of the airplane, they will then be susceptible to rupture by items in the cargo compartment in the event of a belly landing which is the more conventional type of damage anticipated in emergency landings. We note in the Salt Lake City accident that the bottom of the fuselage was crushed upward approximately 20 inches. It is for this reason that the fuel lines were initially located in their present position. It is recognized that the fuel lines can be strengthened and their resistance to impact or shearing type failures can be improved. ”

“ From the foregoing, I believe you will agree that evaluation of the need for corrective action on the Boeing 727 series aircraft is well underway. I would also like to make it clear that while the attention is focused on the Boeing 727 series, our consideration will also be given to other transport aircraft. Reassessments of transport aircraft with engines mounted in the rear are presently in process and may well lead to their further improvement.
Every effort is being directed by the Agency to continuously seek improvement of crashworthiness safety features. ”

“ With reference to your recommendation to relocate the generator leads, the present electrical leads in the area of the fuel line will be rerouted to a near center position in the fuselage to separate them as far as practicable from the fuel lines. A teflon type cover is being considered for the generator leads so that even if the bus is ruptured due to an impact load, the flexible cover will remain intact under deflection and thus reduce the likelihood of ignition of a fire.
We note your observations concerning landing gear failure on the Boeing 727. ”