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Earlier investigations have shown that the introduction of linear sidegrooves with a depth of 100 ìm over the full width of centre cracked tensile (CCT)specimen of AA5083 does not affect the crack growth rate. It was shown that the sidegrooves suppressed the formation of shear lips. The aim of the present study is to forcethe crack path in a certain direction by introducing deliberate defects, i.e. curved sidegrooves, to increase the crack path and thus the fatigue life. Constant amplitude fatiguecrack growth tests at the same load ratios and a frequency of 1 Hz are performed on AA2024 CCT specimens. Some test specimens have side grooved (curved and linear), otherspecimens are standard and serve as control. The loads on the side grooved and non-side grooved specimens is identical. The curved side groove causes two effects: Firstlythe crack is forced at the surface from flat to slant while the crack in the middle of thespecimen remains flat. This causes a small retardation in the crack growth rate.Secondly the crack is suddenly breaks away from the path it was forced into. Thisresults in a morphological change in the crack surface from artificial into natural shearlip. This ‘breaking out’ process introduces a large amount of crack closure. The resultof the combined effects is a significant retardation of the fatigue crack growth rate.