re: F-35 Joint Strike Fighter Thread
Of course they don't carry unneeded equipment, but the structures are largely compromised. They have the same components, but strengthened for the specific requirements, while designing the aircraft for the specific function might lead to a different arrangement of parts that would lead to less fatigue problems. Remember, as the most obvious example, that the design vertical velocity of an aircraft recovering to an aircraft carrier is twice that of an air force aircraft, meaning that the forces will be about four times as large not only on the undercarriage but also on the anchoring of the undercarriage to the fuselage bulkhead concerned and the structure round about. So a different structural arrangement might be advantageous but contrary to the concept of the common basic plane. It is there that you loose compared with designing the aircraft specifically for its function.
