I suspect your two very cold examples were due to a stuck mixing valve in max cold. The Citation controller tends to operate quite far from the freeze point to avoid freezing up the separator sock. It is a bit too conservative, especially compared to what my MU2 did. Maybe we just need a redesigned controller.


Maybe, but it sure is nice to turn on that freon with GPU and/or right after engine start to get cold air moving.


They are outrageously heavy, like 45 lbs each for mine with the lateral translate option.

But this will make the tail heavy tendency worse, alas. Still a win since you can save 200 lbs in seats and replace that with about 60 lbs in ballast.

Now about that 110 lbs galley cabinet I have up front that I don't use, I'd love to get rid of it and just have a baggage bin or empty space.

Sadly, the majority of these changes make the plane more tail heavy.

Mike C.

I love TRs, but lose that 200# and battery and AC are fine. Just stock extra tires and brakes.

And land only on dry runways.

Mike C.

If it is shooting out ice pellets, then it is not working correctly. That will freeze up the water separator and then things will get difficult since that's your source of pressurized air. The bypass valve will open, but then you are sending water into the cabin.

The main issue with ACM is that it doesn't work to precool the cabin on GPU, and it doesn't work well on the ground with engines at idle, so your passengers suffer a sweaty hot box until you get flying. I had this a lot in the MU2 and it was annoying, despite the fact the MU2 had a really cold ACM output.

My plane has a ground mode that runs more air into the ACM on the ground at idle, but that doesn't make it work that much better.

Mike C.

If it is shooting out ice pellets, then it is not working correctly. That will freeze up the water separator and then things will get difficult since that's your source of pressurized air. The bypass valve will open, but then you are sending water into the cabin.

Mike C.

As Mke C said, being able to cool the cabin via GPU is huge here in the South. Every year we spend the 3rd week of July in Destin, FL with another family. On the day of departure, my son and I arrive ahead of everyone else to prep the plane and load the luggage. Even with the plane sitting on the ramp in direct sun and 100% humidity, the freon AC will keep the cabin at 80F. That is well worth the price of admission (and price of the GPU from those thieves at Atlantic).

The ACM can spit out ice pellets under certain situations.

Mike C.

Mike, were you able to look at those two that worked and define what the difference was?

As Mke C said, being able to cool the cabin via GPU is huge here in the South. Every year we spend the 3rd week of July in Destin, FL with another family. On the day of departure, my son and I arrive ahead of everyone else to prep the plane and load the luggage. Even with the plane sitting on the ramp in direct sun and 100% humidity, the freon AC will keep the cabin at 80F. That is well worth the price of admission (and price of the GPU from those thieves at Atlantic).

Yes.

Runs well on GPU.

Mike C.

Yes.

Runs well on GPU.

Mike C.

We have several $200 portable A/C units that work WAY better than the installed one for ground cooling; especially if you have your own hangar.

Tom, I believe there's some confusion.

Mike will clear this up if I'm wrong, but:

The electric air conditioning works reasonably well plugged into a GPU and without the engines running. No bleeds required.

The Air Cycle Machine (operated with one or both engines running) doesn't work that well on the ground even though it has GND setting that ups the flow from 6lbs per minute to 18lbs per minute. Still isn't up to much on the ground.

So both statements are correct. The same airplane has A/C that works well on the ground and A/C that doesn't work well on the ground.

Do you take them with you on trips?

Example unit?

Mike C.

Tom, I believe there's some confusion.

Mike will clear this up if I'm wrong, but:

The electric air conditioning works reasonably well plugged into a GPU and without the engines running. No bleeds required.

The Air Cycle Machine (operated with one or both engines running) doesn't work that well on the ground even though it has GND setting that ups the flow from 6lbs per minute to 18lbs per minute. Still isn't up to much on the ground.

So both statements are correct. The same airplane has A/C that works well on the ground and A/C that doesn't work well on the ground.