What are those downward facing fins at the rear end of Airbus A321-251NX?

When I was a kid I used to unlock and open the door so that I could leg it down the aisle as soon as I hit the flush button because I was scared of getting sucked down the toilet

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Candle-Jolly@reddit

even APUs

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VanDoozernz@reddit

IFF

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nlcircle@reddit

You mean ‘SSR’.

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Nighthawk-FPV@reddit

Reverse F16 bird slicers

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michaelhbt@reddit

chemtrail vents

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Accidentallygolden@reddit

Runway scratchers

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MoccaLG@reddit

could also be those "landing system" or "data aquisition" antennas.

The longer the antenna, the lower the frequency.... so must have high frequency which means low range. Therefore something which has to do with stuff around airport.

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MisterJSP@reddit

Those are drain masts for the apu or the compartment, like engine drain masts they are just bare metal.

The antennas you are looking for are in the front of the aircraft.

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MoccaLG@reddit

i know, u/MisterJSP never seen them in the back. Think youre right... not sure tho

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MisterJSP@reddit

As u/tracernz mentioned

https://www.youtube.com/watch?v=y_RV5KdiGr0

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