Complex sentence: The aircraft had a typical endurance of 5-6 hours and a maximum altitude of 25,000ft; the Double Mamba powerplant tended to be used singly in cruise mode, with engine use alternated between either of the two engines every half an hour.
Split into simpler sentences: The aircraft had a typical endurance of 5-6 hours and a maximum altitude of. The Gannet tended to cruise on just one engine of the Double Mamba powerplant; alternating between the two engines every half an hour.