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HAWK21M
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Breather Port - RB211-535E4

Sat Apr 13, 2013 10:04 am

http://sphotos-d.ak.fbcdn.net/hphotos-ak-prn1/625577_10152762728955301_1669343527_n.jpg

The Breather port on the RR RB211-535E4 of the B752 has got small vortex generators on the lower end on either side and the bottom..
Anyone having any more data on this.
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CCA
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RE: Breather Port - RB211-535E4

Sat Apr 13, 2013 1:49 pm

I'd guess it causes a swirling motion to keep the oil mist off the cowling, the drain mast alone doesn't do the job adequately.
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oly720man
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RE: Breather Port - RB211-535E4

Sat Apr 13, 2013 2:19 pm

I'm inclined to say that the vgs are to generate a "layer" in the flow to stop the ejected flow from the mast from smearing along the nacelle. I can't imagine any aerodynamic reason related to the mast itself.

As for the perpendicular tab, it may just be to guide the flow.
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HAWK21M
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RE: Breather Port - RB211-535E4

Wed Apr 17, 2013 8:29 am

Makes sense....Anyone aware of the earlier breather ports not having these VGs and there after getting fitted on.
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NDWDCPGUY
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RE: Breather Port - RB211-535E4

Thu Apr 18, 2013 12:07 am

Initially there was no vane. The oil/air mixture exited from a flush mounted grille on the cowl. Many of these cowls are still in use.
 
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HAWK21M
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RE: Breather Port - RB211-535E4

Thu Apr 18, 2013 10:33 am

Quoting NDWDCPGUY (Reply 4):
Many of these cowls are still in use.

Do you have a reference to the concerned SB.
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boeingfixer
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RE: Breather Port - RB211-535E4

Thu Apr 18, 2013 3:00 pm

Quoting HAWK21M (Reply 5):
Do you have a reference to the concerned SB.

The Rolls Royce SB is RB.211-71-9088 dated 17 Dec 93.

Quoting HAWK21M (Reply 3):
Makes sense....Anyone aware of the earlier breather ports not having these VGs and there after getting fitted on.

As NDWDCPGUY said, the original breather was a flush louver on the cowl panel. The SB introduced the extended breather mast to keep the oil streaking on the fan cowl to a minimum. The small vanes on this new mast have been there since day one.

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HAWK21M
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RE: Breather Port - RB211-535E4

Sat Apr 20, 2013 1:15 pm

Quoting boeingfixer (Reply 6):

The Rolls Royce SB is RB.211-71-9088 dated 17 Dec 93.

Thanks...I'll check it out....
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