Why are manufacturers so coy about o.w.e.?
 

I was looking back at some old books and magazines and had no trouble finding a published figure for operating weight empty or basic operating weight for most aircraft types. This seems to be very difficult to find these days - I've managted to find a few references on websites. Why is this? I can think of three possible reasons:

- Manufacturers may be not wish to publish figures as they are concerned about not meeting targets and the consequential contractual liabilities.

- The weight may change (hopefully reduce) during the life of the product

- The weight of airline specified cabin fittings may vary so much that it makes a single published figure meaningless

There may be other reasons I haven't thought of. Does anyone have any thoughts.

If it is not confidential could people let me have figures for recent types if possible stating airline.

Manufacturers may be not wish to publish figures as they are concerned about not meeting targets and the consequential contractual liabilities.

Such would relate to a specified build state. Even then, the figures will vary. I spent some years looking after a squadron of nominally identical aircraft .. while the equipment list etc confirmed that, the weights/CGs gave the lie to the fiction.

The weight may change (hopefully reduce) during the life of the product

Rarely reduces. Invariably, in normal service, the empty weight increases, due mods, repairs, general dirt and rubbish and so forth. One usually only sees a reduction of note associated with a significant mod program (eg change a bunch of ancient valve kit to you beaut electronic stuff or, more commonly, a good clean out). I recall a DC3 I used to look after many years ago - had a real good clean out during a major and shed several hundred pounds in the process

The weight of airline specified cabin fittings may vary so much that it makes a single published figure meaningless

For a fairly common fleet, one might use fleet average weight data to save some dollars on reweighs. However, usually it is preferable just to run with the individual hull data to minimise any required ballast fudging and, in consequence, maximise useful (ie dollar producing) payload.