Historical clue formulations

• Airplane course — 2018-08-15
• Airplane's direction — 2017-01-03
• Missile heading — 2012-09-25
• Course taken by a plane or missile — 2011-10-24
• Airplane heading — 2010-07-29
• What an arrow may represent — 2009-11-19
• Missile's course — 2008-07-06
• Missile datum — 2005-12-09
• Missile's heading — 1996-09-29
• Missile's heading — 1996-01-18