 However, this was dependent upon two factors, the serviceability of aircraft – arising from both battle damage and from damage to aircraft on the ground from bombing and strafing – and the serviceability of the runway due to bomb damage.Prior to the arrival of its Spitfires, on several days in April and early May the squadron could only muster 3 or 4 serviceable Hurricanes for scrambles.On 17 March Lawrence was promoted to Flight Lieutenant.