During 1996, "Charles Upham" made two operational voyages to test the ship's capabilities. The first was between Napier and Lyttelton, then on 24 June, the vessel sailed from Auckland to Fiji as part of Exercise Tropical Dust. En route to Fiji, the lightly laden "Charles Upham" showed a propensity to roll, and reached 37 degrees from centre during one heavy storm; the degree of roll caused the main fuel pump to fail and the ship experienced a broaching effect. The conditions led to the ship being nicknamed "Charles Chuckam" and "Chuck-Up", and the commanding officer was so concerned for the safety of the ship and his personnel that on return to New Zealand on 3 August, "Charles Upham" was withdrawn from service until modifications could be made to improve stability. Other alterations planned as part of this conversion included the installation of a flight deck and facilities for two mid-size helicopters, and an increase in soldier accommodation by 100, bringing the number of available berths for ship's personnel and passengers to 215. Investigation found that up to of cargo or ballast (half the ship's designed load) was required to minimise excessive motion, and operation of a helicopter in even these conditions would be limited. Cargo unloading capability at undeveloped or damaged wharves was also found to be poor, with cranes unable to be fitted because they would further compromise stability, and container forklifts were too heavy for the ship's -per-axle deck weight limit.