Historical clue formulations

• Pilotless planes — 2013-05-21
• Unmanned aircraft — 2013-04-30
• Some reconnaissance craft — 2007-01-21
• Bagpipe sounds — 2006-08-17
• Pilotless planes — 2003-10-14
• They have no sting — 1998-10-11
• Boring lecturers — 1996-03-08
• Hive loafers — 1995-03-17