While I can't speak to the specific aircraft, this is not at all an unusual approach to the CG control problem.
In general, if fuel is to be used as ballast (eg for CG control or wing bending relief requirements) then it has to be surplus to the fuel burn requirements either for the relevant stage of flight or, more generally, for the entire flight.
For a specific aircraft, if a ballasting procedure is described in
(a) the AFM or OEM Weight and Balance Manual (this may be done explicitly or implicitly), or
(b) other approved documents (eg approved Loading System)
then it is reasonable to presume that it is OK.
Last edited by john_tullamarine; 20th Feb 2004 at 10:52.