View Full Version : 737 Left or Right Pack

18th Mar 2003, 19:32

I have just got my rating on the 737-300 recently and wonder if there is any preference on selecting which pack to on during the parking scan.
I was told to use left pack as we can preclude FOD digestion into airconditioning intake duct during cargo loading on the right side of the aircraft.
Has anyone experience this?

On the other hand, if we use left and right pack on alternate transit, we can have more or less the same wear and tear for the packs.

Would appreciate if someone can enlighten me on this.

18th Mar 2003, 23:26

I'm not so experienced, but never heard about FOD ingestion on the pack inlet.
Policy from my company says that the preference will be given regarding cargo or pax loading. Thus, we prefer to use LH pack when loading cargo, and RH pack when embarking passengers (comfort for both of them).
Hope this helps a little!


18th Mar 2003, 23:38
I prefer to use the right one, both on the 737 and the 757. This is just because it is quieter in the cockpit with the right one operating, rather than the left one, as the intake into the cockpit is taken from the left pack.

I have never heard of a FOD into the packinlet so I don't think that should be an issue.

Cross Check
19th Mar 2003, 12:34
No company requirement - pilot discretion.

Personally ... (my first time operating in fairly nippy conditions) stepping onboard a cold soaked aircraft first up is APU on (if it isn't already), logs and cabin inspection (by then 1 minute is up), left pack on high and go for a walkaround. Get back, cockpit and fwd cabin is peachy (fwd cabin FA's are happy ... very important ;) ), left pack off and right pack on - warm up the rest of the world and it's now quiet enough to think (less noise coming in from #1 FWD Entry) :cool:

19th Mar 2003, 17:01
Good plan, Cross Check - also gets the tea pressure up early!:p

20th Mar 2003, 16:14
Thanks for the tips guys.
I guess it's up to our own needs and preference.

21st Mar 2003, 01:24
The prospect of FOD ingestion into the r/h pack due to loading baggage etc is minimal.There is a deflector door that extends when the a/c is on the ground to obstruct any debris from entering the ram air duct.This is primarily for use when the a/c is in motion.
There is no prospect of the suction into the duct picking up any pieces from the ground.On the classic 737 the suction is induced by a separate turbofan and on the NG it is by a fan common to the shaft of the ACM.
The answer lies as to whether you wish to warm the cabin or the flight deck.By operating the r/h pack,all the air flows to the cabin,the l/h pack 20% will flow to the flight deck,with the rest going to the cabin.If you're the first one there on a cold day I suggest the left!