Quantas 744 Depressurisation
Forget Fairing failure initiating this amount of damage. Skin is the old waffle doubler construction I believe. Two sections of frames missing and the remains of at least two stringer repairs obvious. Other stringers seem to have failed pretty cleanly each side of the hole ? and the fwd frame has failed at some frame joint ?. And why the fillers under the frame feet ? Usually only do this if you replace a frame or skin. The remaining protruding forward Lap joint is very interesting as the lower skin is not connected to it ! And can you see the edge of a Lap joint scab repair ? Looking for the broken bits of frame or frame chord or safety chord but can’t see any - I believe that’s an intercostal sticking up in the lower part of the hole. This looks awfully like a structural failure, with some collateral damage. Don’t see any clues as to where the failure started but the experts will.
At a guestimate of 80,000 hrs and 12,000 cycles this aircraft would be deep into its ageing aircraft and corrosion control inspection programmes plus a whole raft of SB and AD inspections.
Shrewd observations enchrisg and others,
If I am not mistaken, this whole area is the notorious section 41, section 43 mod vicinity. These mods were carried out in the late 80's-90's because it is very easy to pressurize a cirular airframe shape, but very difficult to pressurize an egg shape as the 747 is. Circular structure is more predictable in stress anyalysis, load bearing risk, not to mention repair. Add to this cocktail the persistent corrosion issues under galleys or lavs; and then factor in management's ability to postpone mandatory million dollar repair programs for years and you have all the ingredients necessary for a drink called a widowmaker at midnight on the figurative airframe clock.
Every time a loud "oil-can" noise went off on climbout, the two guys up front looked at each other like: Is this the big one?
The fix they said? "Just write it up."
"Ground checks O.K! O.K to continue..."
BONG, BONG, BONG....
Ask not who the BONG tolls for. The BONG tolls for you..... The BONG tolls for me.
