Mr Spaceman From Canada, joined Mar 2001, 2787 posts, RR: 9 Posted (9 years 9 months 1 week 4 days 4 hours ago) and read 5264 times:
The photographer of this photo asks ........
"There is a huge tube in there, anybody know what it's for?"
I'd like to know the answer too.
Actually, there are 2 metal tubes that can be seen inside this KLM 747-206's belly. One's close to the wing root and the other huge one is deep inside under the middle of the cargo hold floor.
What are these tubes used for?
For the fun of it, I'll take a guess. They're both used for the 747's Environmental Control System. The smaller tube supplies hot bleed air from engines #3 and #4 to the Air Conditioning Pack's Heat Exchangers and Air Cycle Machines (these 3 A/C packs are located near the main landing gear bays). The air then flows from the A/C packs (at cabin air temperature) via the huge tube in the belly and is then transported via ducts to all the overhead air vents in the passenger cabin, cockpit, & cargo hold, where it's used to pressurize the aircraft and control air temperature.
747NUT From Australia, joined Sep 2004, 78 posts, RR: 0
Reply 4, posted (9 years 9 months 1 week 3 days 19 hours ago) and read 5059 times:
The smaller of the two tubes is the pneumatic ducting that comes from the #3 & 4 engines (there is also one on the opposite wing for the # 1 & 2 )
The larger duct is the ram air cooling for the airconditioning heat exchangers, you can't see the intake on that photo but you can see it on this one.
Mr Spaceman From Canada, joined Mar 2001, 2787 posts, RR: 9
Reply 5, posted (9 years 9 months 1 week 3 days 18 hours ago) and read 5038 times:
OK, so those tubes do provide engine bleed air for the 747's pneumatic system and the environmental control system..... I was close enough! Thank You, Thank You, no applause please .... just throw money!!!
It's kinda neat to see inside the guts of a 747's belly.