Take a look inside an Amazon Air Boeing 737, the latest weapon in Jeff Bezos' master plan to win the delivery wars

Amazon promises speedy delivery on millions of items, and launched its own airline in 2016 so it could have its own cargo planes to fulfill that promise.

It has expanded that fleet since, most recently with an announcement in February that it will fly 85 planes by the end of 2022.

Amazon will be using the 15 new planes after they were bought by GE Capital Aviation Services (GECAS).

The cargo planes are actually converted Boeing 737-800 passenger planes, which Boeing calls “BCF”s, or Boeing Converted Freighters. You can see the passenger windows blocked out on the side of the plane.

But Boeing also created a whole new door on the side of the plane to install cargo, which is hydraulically operated.

Crew enter the plane by the smaller side door, where they enter a space between the cockpit and the cargo hold.

The cargo hold is separated from the crew area, but is accessible through a small door. The wall protects the crew from the force of the cargo, in case it moves.

The hold is pressurized, so animals can travel in the space.

The ground is reinforced, and more cargo is stored underneath. It can carry almost 23 tons of freight.

Only two people can enter the area at a time during a flight to handle cargo, including animals and perishable goods like food.

The floor is made up of clips and rollers to move and secure cargo.

Dave Clark, Senior Vice President of Worldwide Operations at Amazon, said that the new planes “create additional capacity for Amazon Air, building on the investment in our Prime Free One-Day program.”

Amazon has been delivering more of its products itself, investing in a vast network of transport systems.

This plane originally entered service in 2004, and was recently converted. Alvey Pratt, the director for converted freighters at Boeing Global Services, said the conversion process is “relatively straightforward” and takes around 90 days.

Converting a plane costs around $5 million for planes that don’t require additional maintenance or extra features, Pratt said.

Boeing is ramping up the rate at which it converts 737-800s into BCFs, Pratt said, going from eight planes in 2018 to 17 in 2019.

Pratt said that a 15 to 20-year-old plane is a good age to convert into a cargo plane, and said that some companies were buying older planes to convert them as an “asset.”

He said that this conversion process can “add decades” on to the lifespan of a plane.

Boeing is predicting that it will deliver 2,650 freighters between 2018 and 2037, and that more than 60% of these will be converted from passenger planes.