  The Scientific objectives of the LOFT mission, e.g., the study of the Neutron
Star equation of state and of the Strong Gravity, require accurate energy, time
and flux calibration for the 500k channels of the SDD detectors, as well as the
knowledge of the detector dead-time and of the detector response with respect
to the incident angle of the photons. We report here the evaluations made to
asses the calibration issues for the LAD instrument. The strategies for both
ground and on-board calibrations, including astrophysical observations, show
that the goals are achievable within the current technologies.
