It's precisely because of the MLA issue MG that I thought to investigate this issue further - Initial informed advice given to us about 18 months ago was that the main tank contents would be available to just below 100kgs - clearly this is not the case! And I must thank those people who have posted informative, helpful and non-vituperative replies for their efforts. In the light of this however, I do wonder though why the MEL allows the Ac to fly with one Tx pump U/S?