Pellerin was originally scheduled to fly in this mission, as he had done on the 17 June flight, but he was unavailable for the 24 June flight and Wolff was selected as the replacement aircrew member. Due to the short notice of his assignment to the mission, Wolff did not participate in the pre-flight briefing and boarded the aircraft after the engines were started. He was therefore unaware of the planned mission profile and had no opportunity to raise any objections before take-off.[1][page needed]