SHORTCOMINGS of the converted passenger plane are at least 10 in number, says Mr. Froesch, classifying them as follows: (1) floor slope and irregularity of floor at door causing concentration of load at that point; (2) floors too weak, requiring reinforcing; (3) doors too narrow for entrance of bulky loads; (4) no anchorage for load fasteners; (5) no provisions for cargo handler station; (6) hard to distribute load so as to give a satisfactory center-of-gravity location; (7) lavatory in the wrong place; (8) insufficient fire extinguisher protection; (9) door sill heights too variable; (10) circular or oval fuselage shape, which cannot be used effectively.
A big problem is to get the rate down to the point where repeat business will follow. Eventually this might mean a 10 to 12¢ per mile rate under proper designing, Mr. Froesch declares. But, he says, size and capacity of the cargo plane cannot be predicted until a thorough analysis of the air express and freight market has been made.
A density-volume ratio of 8 to 9 lb per cu ft can be used, Mr. Froesch says, as a design criterion in figuring size of compartment. He points out heating and ventilation aspects of the cargo compartment and explains desirability of having a small compartment for protection of valuables close to the cockpit. The airplane should also be designed so that preventive maintenance and service methods can be best applied.
