Cool Aviation Stuff For Sale

EAA Chapter 517 in Missoula, Montana has a bunch of cool aviation items for sale that were donated to the Chapter. All items can be shipped at the buyers expense. We'd love to have you come by and pick them up and check out our hangar. Check the Sales page on the Chapter website: www.eaa517.org

All right, three neat things on that page: The "Closing Speed" instrument, the "Lead Trail" instrument, and the "Time of Fall" instrument.

I'd never heard of any of these. Can anyone tell me what they did, how they worked, and what they were installed on?

Ron Wanttaja