146 Tops
Guest
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Van Goff,
It actually depends on the pressurisation controller fitted: one is good for FL310 but the old one is only good for FL300.
As Clarrie said, they will go there but more often than not the icing limitation will keep you down to FL260.
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Stay Alive,
[email protected]
It actually depends on the pressurisation controller fitted: one is good for FL310 but the old one is only good for FL300.
As Clarrie said, they will go there but more often than not the icing limitation will keep you down to FL260.
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Stay Alive,
[email protected]
Guest
Posts: n/a
A pinch of salt to the soup... on our RJ100 mark II, digital pressurization allow us to climb to FL350, which we sometimes do. Our SOP have tables showing max weight (acc to OAT) for certain levels and 350 will only be reached if around (don't have the figures here right now) 38 or 39T. Routing say from GOT to ZRH will reward you with savings of approx 250 kg of fuel 
On the other hand we do routinely climb to 310 with the "standard" RJ85/100 series. This mostly for fuel savings, but depending on the situation also to fly above wx or enjoy tailwinds
The more I fly it the more I like it
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... cut my wings and I'll die ...
On the other hand we do routinely climb to 310 with the "standard" RJ85/100 series. This mostly for fuel savings, but depending on the situation also to fly above wx or enjoy tailwinds
The more I fly it the more I like it
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... cut my wings and I'll die ...
Guest
Posts: n/a
To further clarify my post, I'm operating 146 only and usually at ISA+15 to ISA+20.
In fact I've forgotten what ISA is!
(edited because I'm pathalogically unable to proof read from the submit page!)
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bottums up !
[This message has been edited by Capt Claret (edited 22 February 2001).]
In fact I've forgotten what ISA is!
(edited because I'm pathalogically unable to proof read from the submit page!)
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bottums up !
[This message has been edited by Capt Claret (edited 22 February 2001).]
Guest
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4 Dogs. I think you will find it has more to do with the aircraft having auto-drop down capability of the oxygen masks rather than the pressurisation controller. If an a/c does not have auto drop down oxygen i.e. when the cabin reaches a pre-defined altitude (which in the RJ/146 is 13,250' to 14,500', the oxy masks should drop down automatically) then it is restricted to 30,000'. The older pressurisation controllers are quite capable of selecting a cabin altitude of 8000', or higher if required for zero differential at 10,000'.
The time and fuel it takes to get a heavy 146 up to that altitude sometimes negates the benefit of being up there. The loss of TAS with those poor old 502 engines above 26,000' to 27,000' can also be relevant. Unless we are doing longer sectors i.e. in excess of 1 hour 30 mins, it is hardly worth the time or effort to go to those levels, particularly when it is warmer.
I recently had the opportunity to fly a 300 nm sector out and back with little or no wind effect. We cruised at 26,000' going over and due to ATC restrictions, at 19,000' going back. We burned 20 kg's more fuel at 19,000' and got there 3 minutes earlier. So much for the benefit of climbing a 146 to altitude hey? Obviously over longer sectors there are tangible benefits at altitude.
Other considerations are temperature, headwind and icing. Godbless the poor old 146!
We could discuss this topic for quite an extended peroid of time without resolution so I will leave it at that.
[This message has been edited by shakespeare (edited 25 February 2001).]
The time and fuel it takes to get a heavy 146 up to that altitude sometimes negates the benefit of being up there. The loss of TAS with those poor old 502 engines above 26,000' to 27,000' can also be relevant. Unless we are doing longer sectors i.e. in excess of 1 hour 30 mins, it is hardly worth the time or effort to go to those levels, particularly when it is warmer.
I recently had the opportunity to fly a 300 nm sector out and back with little or no wind effect. We cruised at 26,000' going over and due to ATC restrictions, at 19,000' going back. We burned 20 kg's more fuel at 19,000' and got there 3 minutes earlier. So much for the benefit of climbing a 146 to altitude hey? Obviously over longer sectors there are tangible benefits at altitude.
Other considerations are temperature, headwind and icing. Godbless the poor old 146!
We could discuss this topic for quite an extended peroid of time without resolution so I will leave it at that.
[This message has been edited by shakespeare (edited 25 February 2001).]
Guest
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Shakey,
You are quite right, I was being a bit brief. What I call the "old" controller is that for the the manual deployment system which is limited by certification rules to 30000'.
I am not aware of the "new" controller being associated with any system other than the auto deployment system. Are you?
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Stay Alive,
[email protected]
You are quite right, I was being a bit brief. What I call the "old" controller is that for the the manual deployment system which is limited by certification rules to 30000'.
I am not aware of the "new" controller being associated with any system other than the auto deployment system. Are you?
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Stay Alive,
[email protected]
