This is where Yuna tries to fix the hole in Nightstar's wing in The Alliance of Berk and Equestria.
[it is now nighttime and we view Princess Luna, Snowdrop, Nyx, Skyla, and Yuna in the Canterlot library.]
Princess Luna: And then, he twisted off his wing and swallowed it whole!
Princess Luna: Golden Spear then take a look at the Dragon's eye and could read what he was thinking. "He tasted good."
Skyla: What else?
Princess Luna: The next day, another Dragon came and took his right arm!
Nyx: Isn't it something to think your hoof is inside a dragon so you could still have control of it? Like Potato Head's arms, then you could kill the dragon from the inside.
Luna's Royal Guard: It makes me so angry! I'll avenge his arm! I'll tear one off every dragon I see!
Skyla: Oh, my.
Princess Luna: No, it's the wings you want. If it doesn't have them or has a injured to them, it can't fly away. Then it's as good as dead.
Yuna: [in her mind] So that's why that Night Fury doesn't just fly out!
Princess Luna: Yuna?
Princess Luna: Is something on your mind?
Yuna: Oh no, I'm just fine.
Princess Luna: Okay. [gets up] Alright, it's time for you foals to head to bed. There's a whole new day ahead.
[but we see Yuna has already left]
Skyla: [watches Yuna race off] Hmm.
Yuna: [takes out her sketchbook and then draws a patch for the hole on the dragon's wing. She then constructs a patch]
[back at the cove]
Yuna: Hey, Nightstar. I brought breakfast, hope you're hungry. [dumps out a basket of fish]
Nightstar: [eats the fish]
Yuna: Yeah, that's it. Don't mind me. I'll just be over here minding my own business. [she then takes the patch and begins putting it on the hole in Nightstar's wing]
Nightstar: [brings her head up as Yuna continues]
Yuna: Let's see.
Nightstar: [feels Yuna putting the patch on]
Yuna: It's okay. Okay... okay... There. That's not too bad. It works.
Nightstar: [takes off with Yuna literally on her back.]
[Nightstar then starts to ascend into the sky but then the patch starts to come loose]
Yuna: [uses her magic to hold it in place] Oh my, it's working!
[But then, as they fly above the pond in the cove, Nightstar realizes Yuna is on her back and throws her off]
[but then the patch comes off and Nightstar crashes into the pond]
Yuna: Alright, this is gonna be more tougher than I thought.
[later that day, Yuna constructs a saddle]
Yuna: Here we are. [she then returns to the cove]
[Nightstar playfully runs away from Yuna]
Yuna: Hey! Come back!
[we now see Yuna riding Nightstar in the saddle but she falls off]
[then Yuna constructs a safety harness for the saddle]
[we then see Yuna flying on Nightstar again, but then they get caught in a wind current and they crash, which causes one of the safety hooks to bend]
Yuna: Oh great.
[Then we see Yuna sneaking Nightstar to the shop to remove the connecting cord.]
[Nightstar then bumps a bucket and Skyla hears it]
Yuna: [fixes the connecting hook]
Skyla: Yuna? Is that you?
Yuna: [gasps] Skyla!
[she then comes out the door, making sure to hide Nightstar from sight]
Yuna: Oh, hey Skyla.
Skyla: Are you up to something?
[as they talk, Nightstar sees a crystal sheep]
Yuna: [sheepishly] Uh, what are talking about?
Skyla: Because you're acting weird-ish.
[Yuna is pulled through the shutter doors. Skyla tries to see what happened, but doesn't notice Yuna flying away with Nightstar.]
Skyla: Huh? Hmm.