A closed metal tube in the air in the Walking Dead world means a zombie buffet. Want more Walking Dead? Well AMC is going to give it to you. There will be a 30 minute episode filmed that should air during the Walking Dead, but connect to Fear the Walking Dead. The short episode will take place on an airplane that has an outbreak during the start of the zombie infection.
During the crash, one of the passengers will end up joining the cast of Fear the Walking Dead in season 2 next summer. While not a direct crossover, this will connect the two series a little.
Source: Hollywood Reporter