 Complete the following phrase:  The supply of the He 162 was difficult. A few examples began to trickle through to Parchim from the factories to 1., 2. and 3. Staffel. II. Gruppe was still without the type by the first week of April 1945. On 11 April II. Gruppe transferred to Warnemünde to begin training. I. Gruppe had worked its way up to 13-16 aircraft at this time, 10-12 were operational. Its 40 pilots was in contrast to II. Gruppe which had only 19 with no He 162s. I. Gruppe was making approximately ten flights per day. It is thought that JG 1 had 45 He 162s on strength by 1 May 1945 at Leck, though it lacked equipment. Combat operations were few as the Western Allied invasion of Germany collapsed the Western Front and the imminent Battle of Berlin brought the war to an end. Of JG 1s pilots, among the most successful on the He 162 was Feldwebel Friedrich Enderle, who was killed when his He 162 crashed an exploded on take-off. Enderle had three B-17s to his credit. Oberleutt Emil Demuth led his gruppe on a retreat to Leck by the Danish border in an attempt to keep it from the British 21st Army Group for as long as possible and to begin operations. On 20 April, with the 