The door to door safety.

The rear door is what you must be most careful with. It's spring-loaded and heavy and can leave you permanently speaking in a higher octave. Check that the glove access door is closed before you open the bottom half. If you forget, the glove access will be damaged and the Fox is NMC.

Push the bottom half down until you hear it click. That means it's locked. Push the top half up until it clicks, too.

When you get ready to close the bottom, brace it with your foot before you unlock it. That keeps it from flying up.

Before you crank open the M21 hatch, make sure you've unlocked the hatch's handle. If you don't, you damage the crank.

To lock the two top hatches, push the locking handles all the way to the closed position while pulling down on the latch. If you don't, the hatches aren't locked shut and they will leak.

A good BEFORE PMCS check is to eyeball the hatches for anything that could prevent a good seal. Mud and twigs sometimes keep the hatches from sealing tightly. Clean out any problems.

Don't let the grille doors for the engine compartment slam down. That ruins the detents that let you lock the doors down. Lower the doors all the way down.

Don't use the rear surveyor hatch except in an emergency. It's difficult to climb in and out of it without stepping on the MM1 probe, which is fragile and expensive.