CRJ air cond w/huffer cart?

[Papa Woody]

Yep. And when you finally apply take-off power, the ducts purge into the cabin and it smells like something is burning, big time.

(so I've heard)

Clapped-out air-start machines like the ones typically inherited by the "regionals" have seals from about 1972 which seal......um......nothing.

Thus, the combustion fumes make their way from the pistons all the way thru the crankcase seals into the compressor where they infuse the pack air with the concentrated aroma of an oily diesel clanker.

 

[yournextFO]

This exact topic came up today in training. Straight from the Bombardier man himself, he said not to do this as it is too much pressure for the packs to handle. He also said it smells like dirty a$$!

Too much pressure? The engines on a CRJ200 at take-off power produce over 100 psi on the 10th stage, which is far more than any huffer I've ever seen. It's also why the packs have Pressure Regulating Shut-Off Valves (PRSOV's) which maintain about 30 psi normally.

I'd agree using a bottle to run the packs smells bad, but I've never had a problem with a huffer unless it was poorly maintained.

Tell your Bombardier man to try again.

 

[Papa Woody]

but I've never had a problem with a huffer unless it was poorly maintained.

I've never had a huffer that was maintained!

 

[91100 100 set]

If you really want to try something fun, run the packs off the bottle! Yah 45 min. to recharge.


....and no it was not me.

I know a guy who did that once.

 

[Rally]

What bottle are you guys talking about? Oxygen bottles/fire surpression bottles? (not that I think that) Just a little confused.

 

[CA1900]

What bottle are you guys talking about?

Air start bottles. A big air tank on wheels, used to air-start the engines when the APU is inop. It uses a smaller air compressor that wouldn't be strong enough to start the engines on its own, but is used to charge up the big air bottle, which is used for engine start. Then it has to be recharged, which takes a while...

 

[Rally]

Air start bottles. A big air tank on wheels, used to air-start the engines when the APU is inop. It uses a smaller air compressor that wouldn't be strong enough to start the engines on its own, but is used to charge up the big air bottle, which is used for engine start. Then it has to be recharged, which takes a while...

Ok what happens if they have a double and its not recharged? Thats crazy

 

[CA1900]

Ok what happens if they have a double and its not recharged?

Somebody's probably going to be delayed, but not by 45 minutes, especially if it's a small airplane. An RJ isn't going to deplete the whole air charge.

The odds of a small outstation handling two planes with inoperative APUs at the same time are pretty slim anyway. And a bigger station/hub will have multiple air bottles, a huffer cart (which has a much more powerful compressor that can supply that air continuously), or both.

Thats crazy

No, that's balancing cost versus benefit. (Same reason I don't drive an Excursion around, just in case I might want to buy a boat some day.) A huffer cart is a lot more expensive than an air bottle.

 

[shamrock]

Ok what happens if they have a double and its not recharged? Thats crazy

You get one plane started up then hook a hose up between the two to "jumpstart" the second plane.

 

[Stifler's Mom]

You get one plane started up then hook a hose up between the two to "jumpstart" the second plane.

I'd forgotten about that option. Has anybody actually done this yet.

Too bad the RJ doesn't have a hood on the nose that you can prop up just for asthetics.

 

[Kneeboards Rock]

I was told by MX not to do this since the huffer cart does not care about the quality of the air it puts out, hence the bad smell. An engine will start with air pressure alone. An AC cart is designed to only blow fresh air and not possibly toxic fumes into the cabin.

 

[Flyin2low]

I'd forgotten about that option. Has anybody actually done this yet.

We had a 700 stuck in the Bahamas because the crew shut down both engines with an inop APU and the station didn't have an airstart cart. We flew in another 700 and did the 'jump start' via hose method. Well, the hose split during the start and it stayed there for another day. Our company had to charter a plane to fly in a huffer cart to get them out of there. It's must be pretty bad to be stuck in the Bahamas for a few days.

 

[shamrock]

We had a 700 stuck in the Bahamas because the crew shut down both engines with an inop APU and the station didn't have an airstart cart. We flew in another 700 and did the 'jump start' via hose method. Well, the hose split during the start and it stayed there for another day. Our company had to charter a plane to fly in a huffer cart to get them out of there. It's must be pretty bad to be stuck in the Bahamas for a few days.

Tip for ramper who "accidentally" split the hose: $50

Mini-vacation in the Bahamas: Priceless

 

[BLing]

Too bad the RJ doesn't have a hood on the nose that you can prop up just for asthetics.

Just pop the radome up...

 

[Stifler's Mom]

There you go.

 

[atrdriver]

why not just get an air cart? or is this just a hypothetical question?

Not all CRJs have the low pressure A/C connector. For instance, the ones that came from ACA didn't have that option.

 

[Stepclimb]

We had a 700 stuck in the Bahamas because the crew shut down both engines with an inop APU and the station didn't have an airstart cart. We flew in another 700 and did the 'jump start' via hose method. Well, the hose split during the start and it stayed there for another day. Our company had to charter a plane to fly in a huffer cart to get them out of there. It's must be pretty bad to be stuck in the Bahamas for a few days.

Does the hose have some sort of mechanism for holding open the check valve on the external 10th stage connection? It would appear to me, that the plane donating the air would not be able to get air out unless there is a way to force the one way valve to stay open....

 

[Stepclimb]

Just pop the radome up...

The radome on the CRJ goes to the side......You could always pop up one or both of the doors to the T/R's though.

 

[yournextFO]

Not all CRJs have the low pressure A/C connector. For instance, the ones that came from ACA didn't have that option.

They do now. And they also have conditioned air in the cargo compartment.