Historical clue formulations

• Wash with a glycol spray, as an airplane wing — 2026-06-02
• Prep for the runway, maybe — 2017-10-01
• Clear for takeoff? — 2016-06-26
• Clear for takeoff? — 2014-10-14
• Unfrost — 2014-01-05
• Take a coat off — 2012-07-12
• Clear, as a windshield — 2010-09-09
• Make ready for winter flight — 2009-11-18
• Clear, in a way — 2009-10-08
• Make less chilly — 2009-03-24
• Pour salt on, perhaps — 2007-12-18
• Clear, as a winter windshield — 2007-08-21
• Prepare for winter takeoff — 2006-04-18
• Unfreeze — 2005-02-27
• Clear for takeoff — 2005-02-05
• Clear for takeoff? — 2004-08-08
• Clear in the winter — 2003-12-28
• Prepare wings, perhaps — 2002-05-18
• Spread salt on, perhaps — 1999-09-07
• Clear, in a way — 1998-01-23
• Heater setting — 1998-01-15
• Winter windshield setting — 1997-07-07
• Car heater setting — 1996-11-27
• Clear, in a way — 1996-04-12
• Clear, in a way — 1995-09-17
• Clear the winter windshield — 1994-12-12
• Heater setting — 1994-01-28