Crack growth tests at 150-degrees-C under constant load conditions were performed on compact tension specimens of 7050-T73651 aluminium alloy. The d.c. potential drop method was employed to monitor crack lengths throughout the tests. Fracture mechanics parameters such as the stress intensity factor (K) and energy-rate line integral (C*) were used to establish correlation with the crack propagation rates. As a result of experiments it was found that crack growth rates (da/dt) versus K, over discrete ranges of rates, can be described as a power-law equation in the form da/dt= AK(n). The parameter C* appears to correlate well with the crack propagation rates through a single power law over a wide range of rates.