Part 1 > https://www.furaffinity.net/view/62837135/
Here helping  SpiritDerggie with making his mask

In case a transformation is needed a TF gas mask will be available for you.
Take your mask and pull it toward you. Place it on your snout and breath normally. The gas will start flowing automatically.

Your belly will start transforming and growing first: be sure there's enough space around tou to make it expand.
Your wings will transform if you already have some. If you don't have, new plane wings will grow on your back.
Your tail will grow too and elevators will grow on its sides.
Your hands and feet will turn into rubber and grow until they reach the correct size.
Your snout and head will transform and grow together with the body. The transformation will continue even if the mask become too small to cover your snout completely.
Extra plane parts, such as the radar, will grow at last if needed.

Make sure to help others doing their masks once your transformation is complete.