Here is how Tigatron and Airazor on the search goes in Fantasyland Rescue.
Tigatron: Princess Celestia? Princess Luna?
Airazor: You two wish to see us?
Princess Luna: Yes, Yuna, Dusty and Duck are missing.
Princess Celestia: You two go out there and find them and make sure they're safe at home.
Tigatron: We will. (goes into Beast Mode)
Airazor: Don't worry, We'll get them back. (goes into Beast Mode)
Princess Luna: (crying) I just wanted her in my hooves again!
Princess Celestia: (comforts her sister) It's going to be alright, Little Sister.
Casey Jr.: So, This is how we work hard.
Princess Yuna: Amazing.
Azul: Let's hope we'll find a way to get you guys home.
Dusty Crophopper: (spotted the Jobi Logs) Guys! Look!
Princess Yuna: Jobi Logs!
Duck: That's just what we need for the new Search and Rescue Center in Ponyville!
Tom Jerry: What is the Search and Rescue Center in Ponyville?
Princess Yuna: I'll tell you.
So, Yuna began to tell the Fantasyland Engines and the Human Counterparts about the Rescue Center.
Princess Yuna: The Rescue Center is the base where the rescue team begin the search for anyone who're lost and wounded when being stuck in the wilds.
Human Rarity: You mean...?
Princess Yuna: Yup.
Human Rarity: My word!
Human Sunset Shimmer: Did she know about our pony counterparts?
Princess Yuna: Princess Luna is my mother.
Dusty Crophopper: You know, Vice Principal Luna's Princess and Pony Counterpart?
Casey Jr.: We know what you mean. It's just that there is a tunnel that leads to Equestria.
Duck: The tunnel to Equestria?
Casey Jr.: That's right, It's the only one that no one has used for centuries.
Dusty Crophopper: Tell us more, Casey Jr..
In the flashback.
Casey Jr.: (narrating) Long ago, Many of us engines had gone through tunnels from our home to wherever it would lead us. Suddenly, An Earthquake shook in Fantasyland and the Tunnel was blocked.
Back in present.
Casey Jr.: And no one was able to use it again.
Princess Yuna: That's sad.
Dusty Crophopper: Too bad.
Duck: What if we are to dig the old tunnel?
Azul: Not a bad idea.
Greendale Rocket: What do you think, Tootle?
Tootle: Great idea.
Johnny: I like that too.
Human Twilight Sparkle: I hope this will work.
Dog Spike: So do I.
Casey Jr.: Doogal, What do you think?
Doogal: I thought so too. Because my friends and I've been here before.
Princess Yuna: Wait! You lived in Fantasyland too?
Dusty Crophopper: No kidding.
Train: I came to Equestria before. Then other worlds not far from here.
Princess Yuna: So, You guys can help us with the tunnel?
Ermintrude: You bet, Princess Yuna!
Dylan: Yeah, That's what friends do.
Dylan: So, What's the plan?
Brian: We dig up the tunnel so Yuna, Dusty and Duck can make it back to Equestria.
Doogal: One of them stays here. In case of it happens...
Train: He's not a dog. He's a chicken.
Doogal: All right, all right.
Casey Jr.: We're with you no matter what.
Princess Yuna: Let's go!
Human Twilight Sparkle: Alright!
Dusty Crophopper: We got us a tunnel to dig!