747 Classic question
Thread Starter
Joined: Aug 2007
Posts: 31
Likes: 0
From: No Way
747 Classic question
I never flew the classic, so I have no clue. Saw this on fb:
“On long range sectors, where fuel could be critical, and dodgy weather they (a kangaroo airline) would fly single pac, the air became very stuffy, it was hard to breathe when working, a quick visit to the flight deck confirmed it, only one pac running, they weren't supposed to do it, but they did.”
Could it fly with one pack ops?
“On long range sectors, where fuel could be critical, and dodgy weather they (a kangaroo airline) would fly single pac, the air became very stuffy, it was hard to breathe when working, a quick visit to the flight deck confirmed it, only one pac running, they weren't supposed to do it, but they did.”
Could it fly with one pack ops?
Joined: Jun 2001
Aviation Qualifications: ATPL
Posts: 1,187
Likes: 59
From: OZ
Nope.
For the B747-300 I think there was a "half flow" option on the pack controllers for use in crz. SOP's mandated what pack selection was used and 1 pack was not one of them. Personally I, FEO, only ever used half pack on the Capt direct instructions coz it saved 3/5 of 5/8 of FA fuel. The possible fuel savings disappeared in the static like heavy airframes - OJU was heavy and always had difficulties BKK-FCO while other aircraft made it OK.
For the B747-300 I think there was a "half flow" option on the pack controllers for use in crz. SOP's mandated what pack selection was used and 1 pack was not one of them. Personally I, FEO, only ever used half pack on the Capt direct instructions coz it saved 3/5 of 5/8 of FA fuel. The possible fuel savings disappeared in the static like heavy airframes - OJU was heavy and always had difficulties BKK-FCO while other aircraft made it OK.
Thread Starter
Joined: Aug 2007
Posts: 31
Likes: 0
From: No Way
Nope.
For the B747-300 I think there was a "half flow" option on the pack controllers for use in crz. SOP's mandated what pack selection was used and 1 pack was not one of them. Personally I, FEO, only ever used half pack on the Capt direct instructions coz it saved 3/5 of 5/8 of FA fuel. The possible fuel savings disappeared in the static like heavy airframes - OJU was heavy and always had difficulties BKK-FCO while other aircraft made it OK.
For the B747-300 I think there was a "half flow" option on the pack controllers for use in crz. SOP's mandated what pack selection was used and 1 pack was not one of them. Personally I, FEO, only ever used half pack on the Capt direct instructions coz it saved 3/5 of 5/8 of FA fuel. The possible fuel savings disappeared in the static like heavy airframes - OJU was heavy and always had difficulties BKK-FCO while other aircraft made it OK.
Is half pack similar to low flow on the -400? and was that with 3 or 2 packs ON?
cheers
Joined: Nov 2001
Posts: 2,412
Likes: 17
From: Delta of Venus
Some airlines had an SOP to switch off ONE pack in the cruise ( so 2 packs still running) to reduce fuel burn, in theory, by a small percentage.
Yes, the -300's had a half pack setting as well & low flow on -400. Personally I thought the air on a highly populated 747 was never great in terms of quality or quantity even with 3 packs running.
Yes, the -300's had a half pack setting as well & low flow on -400. Personally I thought the air on a highly populated 747 was never great in terms of quality or quantity even with 3 packs running.
Joined: Feb 2018
Posts: 800
Likes: 279
From: East of Westralia
On the 747-400 we used to have cabin crew ring up / visit the flight deck and ask for more oxygen.. They would not believe that we had no such control.. I’d take the original post with the required pinch of salt... 
Joined: Apr 2004
Posts: 2,166
Likes: 86
From: Planet Earth
In the account of the Qantas 744 that flew non stop from London to Sydney many different fuel saving techniques were used
One of them was to use only one pack for
the entire journey, towards the end of which
they were at FL450
Of course I don’t think they had any more than 20 people on board including pax and crew
One of them was to use only one pack for
the entire journey, towards the end of which
they were at FL450
Of course I don’t think they had any more than 20 people on board including pax and crew
