Excerpt from book: "crew said they slowed airplane to gust penetration speed 150 KIAS. However ATC radar plotted ground speed of 200 knots." (some airframe damage resulted). Question: Thinking about maneuvering speed or gust penetration speed, I always thought that you fly based upon KIAS not ground speed. So in this case since gust penetration speed is 150KIAS should the pilot have flown at 100 KIAS to achieve gust penetration speed of 150 knots to account for the 50 knot tailwind? (200 knot ground speed puts airplane at 50 knots above 150 KIAS or stated another way: 150KIAS + 50 knot tailwind = 200 knot GS) Thanks for the feedback.