Pressurization Systems

[81Horse]

Yes, your absolutely right, I should have posted this thread under training.

And yet ...

 

[rfresh]

6. When automatic and semi-automatic control of the pressurization system is lost, most airliners can legally dispatch a line trip using the manual system. This means one of the pilots must manually control the pressurization outflow valve to control pressurization - however, many airlines will not dispatch this way - Why? Because the precious FE is no longer around.

I see you have a sense of humor. No, actually, the real reason many carriers won't dispatch with manual pressurization control only (even tho it is FAA legal to do so) is because with only two pilots in the cockpit, the manual pressurization control takes so much constant attention, the PNF (pilot not flying) is almost completely consumed with fiddling with the manual controls for most of the trip. However, almost all carriers *will* dispatch this way if it's a ferry flight with no revenue passengers to get the plane to a repair facility.

 

[HawkerF/O]

Rfresh, keep it up. Don't let the losers on here that want to make fun and flame you keep you from sharing this type of useful info. Those are the types that think they know it all and the 1st ones you read about in an NTSB report.

The info is great that you posted. Most of the true professonals have no problem with system reviews from time to time. It keeps a fella sharp. If they don't want to participate, they should skip the thread.

Thanks for posting and in response, I'll post some stuff on icing to see if we have any takers. Thanks again for your post. It was a great review and I'm sure most of us appreciate it, especially the guys about to transition to jets or T-Props. Look for my post on Icing, and I'll look for some of your knowledge on the subject. Thanks again.

 

[Panel Monkey]

rfresh, your systems description is very good, but not all of your information is applicable to all jet aircraft, not even all widebody transports. In addition, the nomenclature used to describe various valves and other parts varies considerably between the manufacturers. Can you share with us please which type aircraft environmental system you're describing for us?

 

[HawkerF/O]

rfresh, your systems description is very good, but not all of your information is applicable to all jet aircraft, not even all widebody transports. In addition, the nomenclature used to describe various valves and other parts varies considerably between the manufacturers. Can you share with us please which type aircraft environmental system you're describing for us?

That's the kind of $hit I am talking about. Who cares what kind of aircraft this is. He is not teaching an aircraft specific type class. He is simply giving a basic systems description on how those items operate. I don't recall him ever saying this is how all aircraft work and there is no deviating from it. Just because you are a PFE, we are sure you know all about this stuff, but getting on here to show everyone how much you know and how wrong this guy is not what his posted was intended for. Just say thanks or since you already know all of this, start your own post like I did on something else. Come on man, you are better than this.

 

[been-there]

Definately one of the best responses on FlightInfo EVER!

a) The Carbon-based Interactive Flightdeck Monitoring Units (CIFMU's).



a) "Air" derives from the Big Bang, which created the universe approximately 13.7 billion years ago; an alternate "theory" is that air was created about 5000 years ago, on a Monday, by an Intelligent Designer. <discuss>



a) Air Conditioning System won't have a thing to do with Pressurization System since that big brouhaha at Hydraulic and Fuel Systems' party last Saturday.



a) Yes, the Jet Engines still call Pressurization occasionally to play nine holes.



a) Cabin differential pressure is a measurement of the hostility and aggression created when passengers on a given flight compare actual individual airfares paid; it's not important for the CIFMU's to know about it, as they have no control over route structures, pricing, marketing, strategic planning, or management compensation.



a) CIFMU control of the pressurization system can result in deployment of the Rubber Jungle, and is therefore not cost-effective.

 

[Petrov]

Thanks rfresh very interesting thread.

 

[81Horse]

Aw, shucks, been-there -- thanks. I was drunk ... I mean inspired.

 

[Amish RakeFight]

I learned a little something. Thanks.

 

[Panel Monkey]

That's the kind of $hit I am talking about. Who cares what kind of aircraft this is. He is not teaching an aircraft specific type class. He is simply giving a basic systems description on how those items operate. I don't recall him ever saying this is how all aircraft work and there is no deviating from it. Just because you are a PFE, we are sure you know all about this stuff, but getting on here to show everyone how much you know and how wrong this guy is not what his posted was intended for. Just say thanks or since you already know all of this, start your own post like I did on something else. Come on man, you are better than this.

Relax, dude. I just curious what aircraft he's describing. I didn't mean any offense to anyone. I just wondered what airplane he's describing. I am familiar with several different types of environmental systems, and I like to compare and learn.

 

[dsee8driver]

Yes, you must be on a twin-engine wide body. That would make sense. I probably should have been more clear when I said that; I was referring to 3 and 4 engine wide bodied jets. They are the ones who have 3 packs.

Any twin engine airliner is going to have only 2 air conditioning packs because one engine cannot feed more than one pack.

I'm on a 4 engine jet and we only have 2 packs...

 

[Gulfstream 200]

Relax, dude. I just curious what aircraft he's describing. I didn't mean any offense to anyone. I just wondered what airplane he's describing. I am familiar with several different types of environmental systems, and I like to compare and learn.

Dont worry about Hawker F/O....he's just a bit "on edge"......

today, after landing, he used the brakes and his boss nearly fired him.

 

[rfresh]

rfresh, your systems description is very good, but not all of your information is applicable to all jet aircraft, not even all widebody transports. In addition, the nomenclature used to describe various valves and other parts varies considerably between the manufacturers. Can you share with us please which type aircraft environmental system you're describing for us?

That is correct, I'm not trying to say this is the way the systems are on all jet aircraft.

Also, as you point out, the names to describe these parts can differ from manufacturer to manufactuer.

The jets I'm describing these systems which operate in the same manner and have the same component names or close to the same component names are the B-727, B-737, B-747, L-1011, DC-10, MD-80 and MD-90 aircraft.

There will always be exceptions as someone pointed out he flys a twin wide body with only 2 packs and recently someone pointed out they fly a 4 engine jet with only 2 packs.

That's what is great about a place like this, even I learn something everyday when others can share about what equipment they are flying on. I find it all very interesting; 4 motors 2 packs, 2 motors on a wide body 2 packs - interesting indeed!!

 

[rfresh]

I'm on a 4 engine jet and we only have 2 packs...

Very cool - that is a DC-8 yes? I imagine because that jet is so old that the engines combined don't have enough bleed air capacity to feed 3 packs?

Does that change if the -8 has had the engine mods to the larger CFM engines I see a lot of freighters using? I'm just wondering if they modified the FE panel and A/C system to handle a 3rd pack or not? Thanks.

 

[dsee8driver]

Very cool - that is a DC-8 yes? I imagine because that jet is so old that the engines combined don't have enough bleed air capacity to feed 3 packs?

Does that change if the -8 has had the engine mods to the larger CFM engines I see a lot of freighters using? I'm just wondering if they modified the FE panel and A/C system to handle a 3rd pack or not? Thanks.

Well the 70 series with the cfms put out plenty of air. I can't answer about the 3rd pack or not since I don't know how much demand a third pack would require. It is better then the NASI system with the 60 series birds.

 

[HawkerF/O]

Dont worry about Hawker F/O....he's just a bit "on edge"......

today, after landing, he used the brakes and his boss nearly fired him.

Of course I am on the edge. Wouldn't you be if your boss came up front everytime you turned final with a cattle prod to make sure those brakes do so much as get tapped? And now you know the rest of the story.

Now Mr. G200, how about that shine box I've been telling you to go home and get???????

 

[sky37d]

While you could question his antics, many people don't know this stuff.

And, some, actually, could care less. Well, that's not the case, it's not that I don't care, it's just intellectual trivia, and quite frankly Charlotte, I don't give a darn. I have enough intellectual trivia to occupy me today, thank you.

I would care, if it was worthwhile to do so, but since it isn't, I don't.
uke: :beer:

 

[Amish RakeFight]

Here's some trivia for ya

And, some, actually, could care less. Well, that's not the case, it's not that I don't care, it's just intellectual trivia, and quite frankly Charlotte, I don't give a darn. I have enough intellectual trivia to occupy me today, thank you.

I would care, if it was worthwhile to do so, but since it isn't, I don't.
uke: :beer:

It's Scarlett

 

[Dangerkitty]

Any twin engine airliner is going to have only 2 air conditioning packs because one engine cannot feed more than one pack.

Actually, I dont think your above statement is true. If I remember correctly the B-757, B-767, and the B-777 all have three packs.

 

[-Xavier-]

Actually, I dont think your above statement is true. If I remember correctly the B-757, B-767, and the B-777 all have three packs.

...and like he said, every aircraft is different and each is tailored to their own specs.

Thanks for the thread Ralph. I've learned some new things.