So, just how did Mortal Engines rip off Star Wars and Han Solo? Actually, let's word that in a nicer way: How did Star Wars inspire the Mortal Engines book series?
Here's a passage from the novel:
The ship that hung at anchor there was not the elegant sky-clipper Tom had been expecting. In fact, she was little more than a shabby scarlet gasbag and a cluster of rusty engine pods bolted to a wooden gondola.
“It's made of junk!” he gasped.
“Junk?” Miss Fang laughed.
“Why, the Jenny Haniver is built from some of the finest airships that ever flew! An envelope of silicon silk from a Shan Guo clipper, twin Jeunet-Carot aero-engines off a Paris gunship, the reinforced gas cells of a Spitzbergen war balloon…”
It strongly echoes what Luke Skywalker says to Han Solo in A New Hope to which Han retorts: “She'll make point five past lightspeed. She may not look like much, but she's got it where it counts, kid. I've made a lot of special modifications myself.”
Fang's point about the makeup of her ship sounds much the same.
There's also a second key Star Wars moment in Mortal Engines and that's the beginning. Star Wars famously opens with Darth Vader's Star Destroyer pursuing Princess Leia's Corvette, The Tantive IV. It's a desperate chase, one of life and death.
“It was a dark, blustery afternoon in spring, and the city of London was chasing a small mining town across the dried-out bed of the old North Sea.”
London (Vader's ship) eventually catches up with the Mining Town (Leia) and consumes it for its resources. Different circumstances but it's undoubtedly the same beat – and that's how Mortal Engines ripped off Star Wars and Han Solo.