Fuel tanks installation of AW139
Does anybody know the reason why fuel tanks of AW139 are located not under the cabin floor like other helicopters?
I found a regulation in Easy Access Rules for Large Rotorcraft (CS-29) (Amendment 4) as follows, but I couldn't find a regulation which cleary describes to prohibit fuel tank installation undert the cabin floor.
CS 29.952 Fuel system crash resistance
(e) Separation of fuel and ignition sources. To provide maximum crash resistance, fuel must be located as far as practicable from all occupiable areas and from all potential ignition sources.