An aircraft's tail compartment where air conditioning equipment, bleed air ducting, hydraulic reservoirs and filters, the APU, and other equipment are usually located. Named so because they're universally cramped, with parts placed in often devilish locations by engineers seemingly solely to screw over the A&P working on it. You will often find yourself working blind or being a contortionist because absolutely everything is in the way. In addition, they're hotter than hell when outside the hangar in the summer, especially when the APU was just run.
Dude, I gotta go in that G4's hell hole and change the rudder actuator. I'm gonna be soaked in sweat and Skydrol.
Send the new guy in the hell hole to change those filters.
I was working in the hell hole and cut the shit out of myself on a fucking cotter pin!
(Referring to the game Minecraft)
A one by one hole that goes extremely far down, usually enough to kill someone with fall damage. The hole is usually in a random and unusual spot.
Person 1: *Falls to their death*
Person 2: "What the heck did you die to?"
Person 1: "There was a random Sims Hole here!"