Before going any further, it is very important for you to know that this photograph of the passenger cabin of tanker 62 was taken before the ballast items were loaded.
Ok, moving on, do you notice the box like structure running across the cabin floor? That is, according to Larry, the floating beam. The floating beam secures the retardant tank to the aircraft. But Larry says that it is another important purpose, it helps to distribute the "considerable weight of the retardant tank (1,500 lbs.) and the retardant (27,000 lbs.) across the front and rear wing spars." Larry told me later that the floating beam acts like a shock absorber. As I understand it, by acting like a shock absorber, the floating beam will absorb the shock as the tanker is taking off, flying, and landing.
Not only is the retardant tank, located below the floor of the passenger cabin (in the belly of the tanker), attached by means of the floating beam, there are attach points fore and aft. Larry explains:
Along with the floating beam, the tank has attachments at the forward and aft ends as well. The four attach points at the floating beam distribute the majority of the weight of the tank and retardant to the wing spars, but there are also two attach points near the front of the tank on top near the outboard corners.
These attach to a reinforced area of the fuselage where the forward baggage compartment and the hydraulic compartments meet in a bulkhead. There are two similar mounting attach points at the other end of the tank where the rear baggage compartment meets the heater and air conditioning compartments All of these are belly compartments below the floor of the passenger compartment.
These mounting attach points don't have the shock absorbing qualities of the floating beam and I've seen individual mounting bolts break on a couple of occasions. Nothing serious, but on a preflight check you can see the tank sag near the broken bolt when it's loaded. On the plus side, I haven't seen one break in the last 15 years.
No comments:
Post a Comment