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HAWK21M
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Bulge On B737 Empennage Area

Sun Jul 18, 2004 7:24 pm


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Photo © Richard Barsby


Whats the Bulge on the Empennage area,at the root of the Vertical stablizer below the front foot of the bear for.
Is it clearence space for the Horizontal Stablizer Operating mechanism.
regds
HAWK
I may not win often, but I damn well never lose!!! ;)
 
LineMechQX
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RE: Bulge On B737 Empennage Area

Mon Jul 19, 2004 12:26 am

Looks like an antenna
 
MD11Engineer
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RE: Bulge On B737 Empennage Area

Mon Jul 19, 2004 12:57 am

The silver thingy in front of the bear´s foot is the pitot tube for the elevator feel mechanism.

Jan
Je Suis Charlie et je suis Ahmet aussi
 
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Starlionblue
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RE: Bulge On B737 Empennage Area

Mon Jul 19, 2004 2:26 am

I believe HAWK21M is referring to the bulge UNDER the front foot of the bear, not the silver thingy in front of the body. It's right above the trim track (or whatever you call it). Seems like strengthening inside the stab needed some more space or some sort of aerodynamic thingy to stabilize airflow over the stab, but I really don't know.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
Mender
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RE: Bulge On B737 Empennage Area

Mon Jul 19, 2004 3:44 am

Here's another view. https://www.airliners.net/open.file/620662/L

Although I haven't worked on the 737 for a very long time it looks like the lower attachment fitting for the vertical fin. What I can tell you is that it has nothing to do with the horizontal stab. All the stab mechanism, attachments and pivots are inside the fuselage.

It's definitely relates to the fin. It is on the rear spar of the fin so it's almost certain to be one of the primary attachment points for the fin.

Hope this helps
 
SafetyDude
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RE: Bulge On B737 Empennage Area

Mon Jul 19, 2004 6:55 am

Here is another question, why does the rear door not have a door handle? Is it because there are rear stairs and there is a handle somewhere else?

 Smile
-Will
"She Flew For What We Stand For"
 
greasespot
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RE: Bulge On B737 Empennage Area

Mon Jul 19, 2004 8:08 am

There is a handle in the fuselage down below the door that you can access from the ground to open the door and extend the stairs.

Jan is right, the bulge is the pitot tube for the elevator feel computer.

GS
Sometimes all you can do is look them in the eye and ask " how much did your mom drink when she was pregnant with you?"
 
Silver1SWA
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RE: Bulge On B737 Empennage Area

Mon Jul 19, 2004 8:49 am

Jan is right, the bulge is the pitot tube for the elevator feel computer.

Again, as stated above, the original question asks about the bulge at the base of the vertical stabilizer UNDER the bears front foot. That is not a pitot tube...

[Edited 2004-07-19 01:50:47]
ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.
 
fadec
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RE: Bulge On B737 Empennage Area

Mon Jul 19, 2004 9:18 am

An interesting bulge indeed! It appears to be the lower aft spar fitting. After looking around I noticed it's only on the older models. (-2xx-3xx-4xx-5xx) The "next generation" 737's have smooth stabs.
 
N766UA
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RE: Bulge On B737 Empennage Area

Mon Jul 19, 2004 9:43 am

Where's 737Doctor when you need him?

Also, I've always wondered what the small fin-like fittings are that go out on either side of the tailfin. There are about 4 or 5 per side.

Seen here just between the stab and the tail:

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Photo © Marcelo Fouquet De Biasi

 
fadec
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RE: Bulge On B737 Empennage Area

Mon Jul 19, 2004 10:03 am

Vortex generators. They are there to "disturb" the boundary layer of air across the surface of the fuselage. This allows for better handling characteristic's across the flight surface roots and off the tail as the air departs the aircraft.

Most commonly found on wing surfaces for the same reason. To disturb the boundary layer of air across the flight surfaces, thus improving their effectiveness.
 
greasespot
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RE: Bulge On B737 Empennage Area

Mon Jul 19, 2004 10:24 am

ahhh Missed it when I never blew up the pig. That bulge actually covers the attach point on the vertical stab to the fuselage. I have removed the vertical stab 2 times on c-checks and Multiple times to NDT the fittings. Because the vertical stab tapers in the back the fitting is actually a little wider than the stab and therefore the aerodynamic fairing has to "bulge" out to cover it.

Greasespot
Sometimes all you can do is look them in the eye and ask " how much did your mom drink when she was pregnant with you?"
 
N766UA
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RE: Bulge On B737 Empennage Area

Mon Jul 19, 2004 10:37 am

Ah, figured it might have something to do with wind vortexes. Thanks.
 
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HAWK21M
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RE: Bulge On B737 Empennage Area

Mon Jul 19, 2004 3:56 pm


View Large View Medium
Click here for bigger photo!

Photo © Marcelo Fouquet De Biasi


I was referring to the Buldge "Below" the bears front foot.The above pic has a clearer view.Not talking about the Feel Computer Vertical Stablizer pitot tube.

Thanks it does seems like the vertical stab attach point.Thanks all.

N766UA....Those are Vortex generators.

Any Idea why the buldge is not present on the NGs.Was the Mount altered in size.
regds
HAWK
I may not win often, but I damn well never lose!!! ;)
 
VC-10
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RE: Bulge On B737 Empennage Area

Mon Jul 19, 2004 10:27 pm

Hawk,

Your profile say you are "Aircraft Maintenance Engineer Licenced in Cat A&C [mechanical stream] on B732/3/4/5" so why ask this question?
 
miamiair
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RE: Bulge On B737 Empennage Area

Mon Jul 19, 2004 10:44 pm

This is a faring that covers the terminal fitting/fuselage fastener.
Molon Labe - Proud member of SMASH
 
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HAWK21M
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RE: Bulge On B737 Empennage Area

Tue Jul 20, 2004 12:13 am

VC-10...The reason I asked this question was because there was a difference of opinion on the same with my collegues & I wanted a clarification from this forum.
And the question that why the buldge is not present on the NGs still stands.
regds
HAWK
I may not win often, but I damn well never lose!!! ;)
 
miamiair
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RE: Bulge On B737 Empennage Area

Tue Jul 20, 2004 1:01 am

It has been re-designed. There is now a flat cover in its place. If you want a pciture out of the IPC, e-mail me.
Molon Labe - Proud member of SMASH
 
SafetyDude
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RE: Bulge On B737 Empennage Area

Tue Jul 20, 2004 7:46 am

There is a handle in the fuselage down below the door that you can access from the ground to open the door and extend the stairs.

Thanks.  Smile
-Will
"She Flew For What We Stand For"
 
CanadianNorth
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RE: Bulge On B737 Empennage Area

Wed Jul 21, 2004 1:18 pm

good eyes, I musta gone through the rear door of the 732 via the open stairs atleast 20 times and have honestly never noticed that...



CanadianNorth
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