Amazon is expanding its own delivery network into the sky, part of a deal with Air Transport Services Group that will use 20 Boeing 767s to serve the e-commerce company’s US customers. The 767 is a workhorse of the air shipping industry; FedEx announced last July it was buying another 50 of them.

Amazon’s agreement—which has been in the works

since summer 2015—is initially set to last five years and is part of the

company’s larger effort to gain more control over its own logistics

network. Rumors about the addition of jets to its delivery network have been swirling since December 2015, under the rumored codename “Aerosmith.”

Amazon has been working to remove middlemen from its delivery channels, which can both cut its costs and shorten delivery times. In January, the company’s Chinese arm registered to deliver its own products to seaports for ocean shipping. Dave Clark, Amazon’s vice president for worldwide operations, said in a statement the jets will be used for ultra-fast delivery to the company’s growing Amazon Prime membership.