What are those in the belly of a 747?

Question

In the next picture what are the items circled in red?

Photographed by Adrian Pingstone in August 2002 and released to the public domain.

related, if not duplicate: https://aviation.stackexchange.com/q/16566/1467 — Federico, Mar 30 '16 at 08:36
This is what is on the other side. Additional details: Why is air mixed with bypass air on the A/C of an aircraft? — mins, Mar 30 '16 at 18:49

score 11 · Answer 1 · edited Mar 30 '16 at 10:06

11

The forward ones are a ram air inlet (NACA duct) for the Environmental conditioning System (ECS) and what looks like an antenna. The aft one is an exit louver for the ECS.

edited Mar 30 '16 at 10:06

Federico

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answered Mar 30 '16 at 08:59

aeroalias

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@Federico You're right. I didn't see that :). Looks like an antenna. – aeroalias Mar 30 '16 at 09:12
I don't think it's an antenna, I think it's a drain, similar to here. – fooot Mar 30 '16 at 15:21

score 4 · Answer 2 · edited Mar 30 '16 at 11:15

4

The forward inlets are air inlets for the air conditioning and pressurisation. I am not sure of the after ringed area.

edited Mar 30 '16 at 11:15

user

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answered Mar 30 '16 at 08:51

AndyW

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What are those in the belly of a 747?

2 Answers2