Operating air conditioning on ground

[killairbus 3]

It's 84 degrees outside and my passengers are cooking at 90. I've got master temp at 65 and the temperature doesn't seem to be getting lower. I have external air conditioning connected packs and air circulation off. Is there anything else I can do cool this jet faster?

 

-Angelo Busato

[Captain Kevin 586]

Turn air circulation on?

[killairbus 3]

The manual said to keep it off

 

-Angelo Busato

[skelsey 765]

Fire up the APU and turn on the packs.

LP pre-conditioned air doesn't always have a lot of puff, especially if outside temperatures are high.

[Captain Kevin 586]

I'm not sure then. I assume you have the APU off. Do you have the packs running at all?

[killairbus 3]

Packs off as instructed in the manual. I could try the APU but I'm refueling at the moment. 

 

-Angelo Busato

[Captain Kevin 586]

Forgive me if this is a stupid question, but is there anything that says the APU can't be running when you're refueling?

[killairbus 3]

No but I always assumed it was a bit of a hazard. 

 

-Angelo Busato

[mwilk 1,106]

3 minutes ago, killairbus said:

No but I always assumed it was a bit of a hazard. 

 

-Angelo Busato

It's not. There was a time when we would fuel with an engine running. Inop APU and no air start available.

[G550flyer 1,013]

Only time APU is off during refueling is when saving fuel. I refuel all the time with the APU running. The only things that's frowned upon when refueling is operating things with high electrical loads and transmitters. Back in my military flying days, rule of thumb was, if its on, leave it on or if it's off, leave it off.

[DaveCT2003 1,820]

What I'd recommend is to stop looking at the procedures from a "All or Nothing" approach, and instead take a situational operational systems approach. The first step is understanding what the systems do/what they're purpose(s) are, how they interact with one another, and how to use them.  By doing this, you can overcome all sorts of situations such as the one you're working to figure out.

The PMDG documentation explains everything you need, however you might also want to check out the Smart Cockpit website which will provide you with specific information on different systems.

Best wishes!

 

[Qavion2 39]

11 hours ago, killairbus said:

No but I always assumed it was a bit of a hazard. 

According to the Maintenance Manual, it's ok to start the APU if it hasn't previously shut down for abnormal reasons. If it does shut down for abnormal reasons, refuelling must be stopped and the refuel hoses disconnected. You must not attempt to restart the APU with the hoses connected.

If there has been a fuel spill, the APU must be shutdown. However, I would say common sense applies. Only a small quantity may have been spilled.

Engineers... Refer AMM 12-11-01 Task 12-11-603-001-001 (paragraph G)

[scandinavian13 5,192]

9 hours ago, DaveCT2003 said:

What I'd recommend is to stop looking at the procedures from a "All or Nothing" approach, and instead take a situational operational systems approach. The first step is understanding what the systems do/what they're purpose(s) are, how they interact with one another, and how to use them.  By doing this, you can overcome all sorts of situations such as the one you're working to figure out.

This! Well said Dave.

I'll echo the earlier comments that the low pressure air isn't the best if it's not within a range of temps. When I worked ramp at IAD, we always had pilots asking if the air was working if it was too cold or too hot outside. It wasn't that the air wasn't working. It was simply an issue where the unit didn't have the power to heat/cool the air fast enough before throwing it at the plane. On cold days, it just just blowing slightly less cold air into the plane. On hot days, it was just blowing less humid, slightly less hot air into the plane.

Throw the APU on and get the thing cool.

[77west 139]

Reminds me of portable aircon units; useless most of the time!

[killairbus 3]

Hey I just thought of using the air starter for running the packs, is that unusual with a functioning APU?

 

-Angelo Busato