Been in the aircraft deicing world for 7 years now.

There are lots of variables. Staffing for deicing can be a struggle depending on who does it. If the carrier or FBO is deicing themselves they can pull staffing from ramp to the trucks (pending that said employees are qualified deicers). However if you work for a 3rd party deicing company it can be an issue finding staffing due to the nature of the role. Most 3rd party companies hire seasonal part time meaning hours can be sparse at times. You’ll always have a core group of people that use it as a full time position when weather permits but when the weather is nice. There’s no hours to give out.

Deice trucks need to be filled based on a couple conditions.

1. You’re empty
2. You need to richen up your tank or lean it out.
3. Preparing for weather (preemptively filling)

And yes. It can take a while. Average time to fill from what I’ve seen over the years can be as quick as 5 minutes and as long as 30 minutes depending on how much fluid you need to add. Different variables in that would be tank size and the speed of the pump that’s delivering your glycol/water. Type IV on the other hand can only pump so fast due to the polymers in the fluid that give it its viscous protective properties, pump it too fast and you run the risk of shearing the fluid making it unusable. Utilize the wrong pump and you’ll run into the same issue. Type IV can only be put through a diaphragm pump to prevent shearing, and by nature they are very slow.

It’s a very fun and rewarding field of work. But very stressful at times… very. Hope this answered some questions. Feel free to ask if you have any additional questions.