Some airline pilots carry plane trading cards — here's how to get one

• Many people have learned through viral social media posts that Delta Air Lines and Frontier Airlines' aircraft trading cards.
• Delta told Business Insider the program was created to share a passion for aviation with customers.
• Wider knowledge of the program could cause issues for flight crew.

Many people are finding out about aircraft trading cards from viral social media posts, but some enthusiasts have collected them for years.