Travel Secrets you might not want to know Luke MacGregor/Bloomberg via Getty Images Share this story One user shared information gained from a flight attendant that, if passengers are told to brace for impact, they should place one hand over the other—not interlace fingers. The top hand will protect the bottom hand from injury during impact. If possible, place the dominant hand beneath. And then things got fun. One user informed everybody that tray tables are rarely sanitized.