A much-discussed topic here if you search. It WAS done, quite safely and successfully, with all the caveats JT and others mention, and frequently avoided waiting for ice to melt where there was no de-icing. I believe the introduction of the 'FFIcing' lines on the wings made it no longer necessary.
If anyone cares to study 737NG weight and balance/limitations they will understand how it was done (or read the threads). It was not that difficult to understand.
Forgot to mention - it was written into a CAA approved Ops Manual.
Last edited by BOAC; 14th Jun 2012 at 15:43.