Exporting as .FBX from Blender to Unity explodes model

Overview of the situation
I've rigged the wheels of an airplane using Blender so that the airplane can drive on the ground in Unity. I tested the rig in pose mode, and the wheels rotate with their bones. The tutorial I used is Rigging a simple airplane.

Here's what the rigged model looks like in Blender:


The problem
When I export the plane as .FBX, Blender explodes the model. This is what I see:

When I import the .FBX file into Unity, the plane appears in the same exploded view, and when I try to transform the wheels so they're in the right position, the transform coordinates change in the inspector, but the wheels doesn't move in the scene view.



My questions for you
1. How can I stop the model from exploding when I export as .FBX?
a. If I can't stop the model from exploding, how can I fix the wheel positioning once the model is in Unity?

 

I fixed my problem by exporting as FBX using the steps in this video!

https://www.youtube.com/watch?v=ktwo4_6yXmM&t=637s