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VIflyer
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Dash 8 Question

Wed Jun 25, 2003 11:59 pm


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Quite a few times I've sat at the end of D concoure at LGA watching planes go by and I've noticed on the Dash 8's that there is a small pipe sticking out of the rear the engine housing which a white smoke or steam seems to be coming out of during taxi (unfortunately you can't see it at all in this picture). I just was wondering if someone could shed some light on what it's coming from and what is causing it.

thanks
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dash8tech
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RE: Dash 8 Question

Thu Jun 26, 2003 4:16 am

That is a fuel vent and what you're seeing is some fuel venting. Frequently on startup, taxi and sometimes on landing.

Look close you can see the vent here...


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Cheers!
 
ScooterTrash
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RE: Dash 8 Question

Thu Jun 26, 2003 10:27 pm

I return after a long absence and here is a Dash 8 question! I am so pleased!

Dash8Tech is of course correct, that is a fuel vent. At my place, we call it the "afterburner."
 
Yikes!
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RE: Dash 8 Question

Thu Jun 26, 2003 11:35 pm

Umm, folks, that's the oil breather tube.
 
ScooterTrash
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RE: Dash 8 Question

Fri Jun 27, 2003 1:40 am

Seems we have some disagreement here. In training (which I admit was a while ago) we were told that was a fuel vent... Then again it was a pilot doing the talking, so ya never know.

Next time I preflight an -8 (it'll be a few weeks until I get my medical back) I will look harder at the aft end of the nacels. If memory serves me correctly, there are two tubes back there, one small and narrow and one wide and unpainted. The wide one is where the smoke comes from.
 
Yikes!
Posts: 284
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RE: Dash 8 Question

Fri Jun 27, 2003 3:11 am

The wide one (about an inch and a half in diameter) is an oil breather tube. Peculiar to the deHavilland series of aircraft and a source of perennial oil staining of the aft nacelles of Twin Otters, Dash 7's & 8's.

Any fuel that is purged during engine shutdown goes into a collection cannister which vents elsewhere during flight.

The little tube is at 90 degrees to the airflow and is a pneumatic trigger mechanism once sufficient airspeed is reached to dump that purged fuel from a dedicated cannister in the nacelle. That fuel goes out a separate line well away from the engine exhaust.

As I recall.
 
ScooterTrash
Posts: 553
Joined: Thu Aug 02, 2001 10:39 am

RE: Dash 8 Question

Sat Jun 28, 2003 5:07 am

Yikes!

Just talked to a wrenchbender buddy of mine. He said "of course that's the oil breather tube, don't you know that?"

Not the first time the mighty Dash has humbled me, and it won't be the last.
 
Yikes!
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RE: Dash 8 Question

Sat Jun 28, 2003 11:25 am

It's a great airplane indeed.
 
apathoid
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RE: Dash 8 Question

Sun Jun 29, 2003 1:41 am

Yikes is absolutely correct. It's nice to hear someone speak so eloquently of my beloved DeHaviland's in here. The venerable Twin Otter is the finest aircraft ever built.
 
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VIflyer
Posts: 452
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RE: Dash 8 Question

Tue Jul 01, 2003 1:44 am

Thanks all for the replys, I use to be LGA based and I couldn't get a straight answer from any of the crews I worked with (mainly because all of them mostly flew Metros, J32s, Saabs, and ATR's).
Thanks again
I reject your reality and subsitute my own

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