Me 163B "White 05" of Erprobungskommando 16

PK+QP being driven away on its inflatable balloon Scheuch-Schlepper. Note the dark rear cockpit bulkhead and light-colored headrest. Just above the left 30 mm cannon opening, another, smaller opening can be seen. This is used for the boresighting device.

Source: "Messerschmitt Komet - Entwicklung und Einsatz des ersten Raketenjägers" by Jeffrey L. Ethell