Hydrogen Alpha
9th May 2012, 19:51
I'd appreciate some guidance from anyone who has experience of load planning within A340-600 cumulative shear load limits.
As understand it from the WBM, there is a certified ZFW cumulative load limit applying to the entire fuselage cantilever section forward of Frame 40, and another certified limit applying to the entire cantilever section aft of Frame 47. The forward limit is independent of CG, while the aft limit is CG-dependent. I assume these are the shear load limits which were increased about 4-5 years ago, resulting in operators demanding compensation from Airbus.
In the WBM I am looking at, the Frame 40 forward limit is about 28 tonnes, and the aft limit is 33.5 tonnes at 22% RC, increasing to about 43.6 tonnes at 41% RC. My reading is that these limits include not only passenger and cargo weights, but also all variable operator items and cabin installations, including seats - in fact everything apart from overhead bins and PSUs, bin supporting structure, and sidewall/ceiling panels.
So on the face of it there is a load limit of 28 tonnes which must include all the above categories of cabin and cargo loads in the 26 metres of the fuse ahead of Frame 40 (which includes 8 PMC pallet positions), and a limit of up to 44 tonnes (CG at 41%RC) to cover everything in the 27 metres or so of fuse aft of Frame 47 (which includes only 6 PMC pallet positions).
Is this correct? Is so, does this mean in practice that you would have to fill the aft hold with about 20 tonnes of bins to exhaust the available payload, but that you'd only have about 12 tonnes to play with in the larger forward hold? The WBM I have is for a WV 001 aircraft (2003); do these limits increase in the WV 101 later production A340-600s?
Any feedback from the Real World much appreciated. :ok: I'm working with some people who are looking at A340-600 at the moment, so if I've got this all wrong now would be an excellent time to find out!
As understand it from the WBM, there is a certified ZFW cumulative load limit applying to the entire fuselage cantilever section forward of Frame 40, and another certified limit applying to the entire cantilever section aft of Frame 47. The forward limit is independent of CG, while the aft limit is CG-dependent. I assume these are the shear load limits which were increased about 4-5 years ago, resulting in operators demanding compensation from Airbus.
In the WBM I am looking at, the Frame 40 forward limit is about 28 tonnes, and the aft limit is 33.5 tonnes at 22% RC, increasing to about 43.6 tonnes at 41% RC. My reading is that these limits include not only passenger and cargo weights, but also all variable operator items and cabin installations, including seats - in fact everything apart from overhead bins and PSUs, bin supporting structure, and sidewall/ceiling panels.
So on the face of it there is a load limit of 28 tonnes which must include all the above categories of cabin and cargo loads in the 26 metres of the fuse ahead of Frame 40 (which includes 8 PMC pallet positions), and a limit of up to 44 tonnes (CG at 41%RC) to cover everything in the 27 metres or so of fuse aft of Frame 47 (which includes only 6 PMC pallet positions).
Is this correct? Is so, does this mean in practice that you would have to fill the aft hold with about 20 tonnes of bins to exhaust the available payload, but that you'd only have about 12 tonnes to play with in the larger forward hold? The WBM I have is for a WV 001 aircraft (2003); do these limits increase in the WV 101 later production A340-600s?
Any feedback from the Real World much appreciated. :ok: I'm working with some people who are looking at A340-600 at the moment, so if I've got this all wrong now would be an excellent time to find out!