One PACK off for fuel savings question
05-24-2009, 09:55 AM
#1
Gets Weekends Off
Thread Starter
Joined APC: May 2006
Position: Admiral's club lounge
Posts: 631
One PACK off for fuel savings question
Are there any Airbus 320 series operators out there running One PACK in the off position for fuel savings?
If so, has it been determined safe and effective?
If so, has it been determined safe and effective?
05-26-2009, 07:04 AM
#2
Line Holder
Joined APC: Jan 2008
Position: B747-400 Captain
Posts: 54
I would suggest that it is safe - after all you can dispatch with one pack inoperative and are limited to FL315 (from recollection). Whether or not is is effective, I don't know, but on the B747-400 with one pack inop, the other two packs run permanently in 'high flow' mode, and the MEL suggests that two packs in high and 3 packs in normal flow result in no discernable fuel consumption difference.
05-29-2009, 05:34 PM
#3
Banned
Joined APC: Aug 2006
Posts: 258
Myth: Pilots turn off air conditioning packs to save fuel.
Fact: While the flight deck does have the capability to shut down an air conditioning pack in the event of a malfunction or abnormality, this is not intended for fuel-saving purposes. In fact, on many Boeing airplanes, when one pack is shut down the remaining air conditioning system automatically goes into a high-flow mode to compensate for much of the capacity of the unit that is turned off. Of course, that means that more air is being taken from the engine compressors by the portion of the system still operating, so there is little to be gained from a fuel-efficiency standpoint. Some early 747s (not 747-400s) do have an economy setting that can be used to save fuel through reduced air flow. This is intended for use at operator discretion when passenger loads are light. However, that feature is no longer offered and, in any case, Boeing recommends all packs be operated at the normal standard setting whenever passengers are on board.
Work same on Airbus. Remaining pack which was at 68% is now at 100%.
from boeing.com airconditiong myths and facts
Fact: While the flight deck does have the capability to shut down an air conditioning pack in the event of a malfunction or abnormality, this is not intended for fuel-saving purposes. In fact, on many Boeing airplanes, when one pack is shut down the remaining air conditioning system automatically goes into a high-flow mode to compensate for much of the capacity of the unit that is turned off. Of course, that means that more air is being taken from the engine compressors by the portion of the system still operating, so there is little to be gained from a fuel-efficiency standpoint. Some early 747s (not 747-400s) do have an economy setting that can be used to save fuel through reduced air flow. This is intended for use at operator discretion when passenger loads are light. However, that feature is no longer offered and, in any case, Boeing recommends all packs be operated at the normal standard setting whenever passengers are on board.
Work same on Airbus. Remaining pack which was at 68% is now at 100%.
from boeing.com airconditiong myths and facts
05-29-2009, 08:26 PM
#4
Gets Weekends Off
Joined APC: Jul 2008
Position: 747 Captain (Ret,)
Posts: 804
At "my house", on the 727 we were directed to turn one pack off for takeoff and climb thru 25,000'. Some crews simply ignored the directive, and others made PA announcements that the cabin was uncomfortably hot because management had directed us to only use half of the air
conditioning system to save money. With the number of complaints from irate pax, this idea did not last long.
Joe
conditioning system to save money. With the number of complaints from irate pax, this idea did not last long.
Joe
05-30-2009, 04:20 AM
#5
Gets Weekends Off
Joined APC: Dec 2007
Position: retired
Posts: 992
Originally Posted by joepilot
At "my house", on the 727 we were directed to turn one pack off for takeoff and climb thru 25,000'. Some crews simply ignored the directive, and others made PA announcements that the cabin was uncomfortably hot because management had directed us to only use half of the air
conditioning system to save money. With the number of complaints from irate pax, this idea did not last long.
Joe
conditioning system to save money. With the number of complaints from irate pax, this idea did not last long.
Joe
Thread
Thread Starter
Forum
Replies
Last Post
RVSM Certified
Flight Schools and Training
22
02-27-2009 12:04 PM
