Boeing is going to use a 747-400 testbed rigged out with sensors to get wing-loading data for its new 747-8.
It's going to have to lease the aircraft from Malaysia Airlines because Boeing doesn't keep prototypes of its airliners anymore, unlike Airbus, which has an A320, a couple of A340s and an A380 in its own "fleet", which come in handy for testing out new gadgets like winglets and laminar flow wings.
I guess there's only so much you can find out in the windtunnel, as my recent picture of the 747-8 Freighter model at Farnborough shows.
