The invention relates to methods of measuring an aircraft under simulated flight-loads while the aircraft is not in-flight. In accordance with the invention, a control is provided which sets the desired system pressure during operation in dependence on an operating parameter of the hydraulic motor. A gradient magnitude and angle are determined for each pixel of the image. In subsequent steps, discrete absorbent pants articles are shaped from the finished web. More particularly, this invention relates to the protection of submerged surfaces with new isonitrile, formamide, isocyanate and isothiocyanate anti-fouling agents. Moreover, the well dopant species is implanted after the recessing, thereby avoiding undue dopant loss.