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Yellow Bracket On Top Of SWA 737-700 Wing  
User currently offlineDandy_don From United States of America, joined May 2000, 202 posts, RR: 0
Posted (7 years 2 months 4 days 17 hours ago) and read 9118 times:

Spent an hour and a half trying to figure out what this small bracket with a hole in the middle (painted yellow) is for?

A tie-down of some type?

53 replies: All unread, showing first 25:
 
User currently offlineOPNLguy From , joined Dec 1969, posts, RR:
Reply 1, posted (7 years 2 months 4 days 17 hours ago) and read 9120 times:

Quoting Dandy_don (Thread starter):
Spent an hour and a half trying to figure out what this small bracket with a hole in the middle (painted yellow) is for?

A tie-down of some type?

In the event of a water evac, there's a line associated with each overwing exit that is extended, and clips to that yellow bracket, as a guide to get everyone out on the wing.


User currently offlineAA737-823 From United States of America, joined Mar 2000, 5780 posts, RR: 11
Reply 2, posted (7 years 2 months 4 days 17 hours ago) and read 9113 times:

It took me a minute to figure out what you were talking about, but now I realize. It's also proiment on the A320.
If I remember correctly, it's a tie down for the overwing escape slides on slide-equipped aircraft.

I have a feeling, though, that someone is about to tell me I'm wrong... just a heads-up.


User currently offlineAA737-823 From United States of America, joined Mar 2000, 5780 posts, RR: 11
Reply 3, posted (7 years 2 months 4 days 17 hours ago) and read 9101 times:

He beat me by 70 seconds...
So maybe I was right in thinking that after all???


User currently offlineLaxintl From United States of America, joined May 2000, 25202 posts, RR: 47
Reply 4, posted (7 years 2 months 4 days 17 hours ago) and read 9103 times:

A320 series also has them.

Single loop close in, and a double loop a little further out.


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User currently offlineCitationJet From United States of America, joined Mar 2003, 2434 posts, RR: 3
Reply 5, posted (7 years 2 months 4 days 17 hours ago) and read 9092 times:

I believe it is a tie-down for the life rafts.

http://www.airliners.net/discussions/tech_ops/read.main/73184/
.

[Edited 2007-07-02 05:37:21]


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User currently offlineOPNLguy From , joined Dec 1969, posts, RR:
Reply 6, posted (7 years 2 months 4 days 17 hours ago) and read 9078 times:

Quoting CitationJet (Reply 5):
I believe it is a tie-down for the life rafts.

It could also be used for that, if the aircraft is raft-equipped (which SWA's aircraft are not).


User currently offlineFlybyguy From United States of America, joined Jun 2004, 1801 posts, RR: 1
Reply 7, posted (7 years 2 months 4 days 17 hours ago) and read 9053 times:

Quoting OPNLguy (Reply 1):
In the event of a water evac, there's a line associated with each overwing exit that is extended, and clips to that yellow bracket, as a guide to get everyone out on the wing.

Wouldn't it be just a bracket for tethering the overwing exit chute in ground evacuations? I highly doubt that water evacs are it's primary use... not only because I don't believe that a water landing by a commerical airliner is structurally survivable, but also because in the very unlikely event that a plane comes to rest in water in tact, tying a life raft down to tiny brackets on the wing would be least of everyones worries.



"Are you a pretender... or a thoroughbred?!" - Professor Matt Miller
User currently offlineOPNLguy From , joined Dec 1969, posts, RR:
Reply 8, posted (7 years 2 months 4 days 17 hours ago) and read 9045 times:

From Wikipedia's entry on "overwing exits"

Use in a ditching
The use of overwing exits in a ditching varies from airline to airline. On aircraft fitted with overwing exits, there is typically a raised "D ring" about a third of the way from the door, on the wings upper surface and is typically painted yellow. This is accompanied by an escape rope found in the frame of the exit after opening and once this rope is attached to the D-ring it will aid passenger evacuation onto the wing to await rescue or to enter the water (depending on the airlines procedures), and on aircraft with life rafts to be launched via the overwing exit, the wing will be used to provide a boarding platform onto the life raft.


User currently offlineOPNLguy From , joined Dec 1969, posts, RR:
Reply 9, posted (7 years 2 months 4 days 16 hours ago) and read 8875 times:

Quoting Flybyguy (Reply 7):
Wouldn't it be just a bracket for tethering the overwing exit chute in ground evacuations?

On a 737-700 (SWA's at least) there's no chute or slide associated with the overwing exit--it's just an exit.


User currently offlineMalaysia From United States of America, joined Nov 1999, 3347 posts, RR: 0
Reply 10, posted (7 years 2 months 4 days 16 hours ago) and read 8827 times:

I wouldnt want to hook my raft to the wing when the plane starts to sink


There Are Those Who Believe That There May Yet Be Other Airlines Who Even Now Fight To Survive Beyond The Heavens
User currently offlineAlias1024 From United States of America, joined Oct 2004, 2755 posts, RR: 2
Reply 11, posted (7 years 2 months 4 days 15 hours ago) and read 8800 times:

Quoting Malaysia (Reply 10):
I wouldnt want to hook my raft to the wing when the plane starts to sink

You wouldn't want your raft to float away before the passengers got into it either.



It is a mistake to think you can solve any major problems with just potatoes.
User currently offlineMalaysia From United States of America, joined Nov 1999, 3347 posts, RR: 0
Reply 12, posted (7 years 2 months 4 days 15 hours ago) and read 8788 times:

Quoting Alias1024 (Reply 11):
You wouldn't want your raft to float away before the passengers got into it either.

But I can swim to it  Smile



There Are Those Who Believe That There May Yet Be Other Airlines Who Even Now Fight To Survive Beyond The Heavens
User currently offlineOPNLguy From , joined Dec 1969, posts, RR:
Reply 13, posted (7 years 2 months 4 days 15 hours ago) and read 8734 times:

Quoting Malaysia (Reply 10):
I wouldnt want to hook my raft to the wing when the plane starts to sink

I think you can safely assume that the intended use here is to have a raft attached to the line only as long as it takes to fill one up with passengers, and then detach it and float off. If the aircraft has already started to sink, common sense should dictate what not to do. Likewise if there's enough buoyancy in those early minutes where the rope can be used. The ALM DC-9 that ditched near SXM back in 1970 stayed afloat for about 10 minutes before sinking.


User currently offlineJBo From Sweden, joined Jan 2005, 2329 posts, RR: 0
Reply 14, posted (7 years 2 months 4 days 15 hours ago) and read 8699 times:

Quoting OPNLguy (Reply 13):
The ALM DC-9 that ditched near SXM back in 1970 stayed afloat for about 10 minutes before sinking.

Difference between a 737/A320 and a DC-9 is where the engines are. I doubt very seriously that a 737 or A320 (or any aircraft with wing-mounted engines) would make a water landing intact without the engines being torn off the wings (and thus, likely the wings themselves being torn off).



I'd take the awe of understanding over the awe of ignorance any day.
User currently offlineOPNLguy From , joined Dec 1969, posts, RR:
Reply 15, posted (7 years 2 months 4 days 15 hours ago) and read 8666 times:

Quoting JBo (Reply 14):
Difference between a 737/A320 and a DC-9 is where the engines are. I doubt very seriously that a 737 or A320 (or any aircraft with wing-mounted engines) would make a water landing intact without the engines being torn off the wings (and thus, likely the wings themselves being torn off).

Be that as it may (or may not), the point remains that Boeing put them there for a reason.


User currently offlineScbriml From United Kingdom, joined Jul 2003, 12515 posts, RR: 46
Reply 16, posted (7 years 2 months 4 days 14 hours ago) and read 8620 times:
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Quoting JBo (Reply 14):
I doubt very seriously that a 737 or A320 (or any aircraft with wing-mounted engines) would make a water landing intact without the engines being torn off the wings

Exactly as designed then! The engine mountings are designed to break away long before reaching loading high enough to rip off the wing. If the water is reasonably calm and it's daylight, a successful "landing on water" is conceivable.

Do I ever want to be in one? no 



Time flies like an arrow, but fruit flies like a banana!
User currently offlineTG992 From New Zealand, joined Jan 2001, 2910 posts, RR: 10
Reply 17, posted (7 years 2 months 4 days 14 hours ago) and read 8618 times:

Standard procedure is to attach the raft's static line to a structural point inside the cabin (usually the metal frame of pax seats, the bottom of which should be attached to the floor in most circumstances).

The D-Ring on the wing is to attach the guide-rope to. You'd send your first able-bodied evacuee out onto the wing with the rope, with instructions to attach it to aid the following evacuees to disembark. There is no suggestion that you'd attach the raft to it, although you COULD in the most desperate of circumstances, because the static line will automatically break with about 700lb of force exerted on it - so as the aircraft starts to sink, the force will cause the line to snap, as designed.



-
User currently onlineWesternA318 From United States of America, joined Oct 2004, 5659 posts, RR: 24
Reply 18, posted (7 years 2 months 4 days 13 hours ago) and read 8553 times:

Quoting Flybyguy (Reply 7):
because I don't believe that a water landing by a commerical airliner is structurally survivable

Aww come on now...we allknow a 747-100 can do it (lol), what makes you think a 737 cant?  bigthumbsup 



Next blog will be up on 8/30/14 around 6PM Mountain Time...check it out at fl310travel.blogspot.com!
User currently offlineSpeedmarque From United Kingdom, joined Jul 2005, 684 posts, RR: 1
Reply 19, posted (7 years 2 months 4 days 12 hours ago) and read 8482 times:

On the A320, A319 the "double loop" is for "Lifelines", as described by others for guiding pax onto wing. The single ring is for use when the offwing slide deflates. There is a pouch with a hook at the top of the slide whach can be attached to thet ring and holds the top of the slide taught, it can then be held at the bottom by people and used as a hand-held slide.

User currently offlineMarkHKG From United States of America, joined Dec 2005, 960 posts, RR: 2
Reply 20, posted (7 years 2 months 4 days 11 hours ago) and read 8443 times:

Quoting WesternA318 (Reply 18):
what makes you think a 737 cant

A Garuda 737 did ditch into a lake and remained structurally intact...resulted in only 1 fatality

http://aviation-safety.net/database/record.php?id=20020116-0

Photo: http://www.airdisaster.com/photos/ga421/1c.jpg

Quoting Malaysia (Reply 10):
I wouldnt want to hook my raft to the wing when the plane starts to sink

This is a non-issue because the raft mooring line, which secures the raft to the attachment point, for the life-raft is designed to break away if under sufficient force, i.e. the plane sinks.

Quoting Flybyguy (Reply 7):
I highly doubt that water evacs are it's primary use

On the A320, the overwing evacuation slides cannot be used for a ditching. Water would enter the aspirators because of its position on the wing, preventing inflation. Further, the slide cannot be detached at the overwing. (The main cabin doors can.) Neverthless, for many A320 operators, the primary exit in a ditching is still the overwing exits as they feel it will be above the waterline unlike the floor level exits.



Release your seat-belts and get out! Leave everything!
User currently offlineStarlionblue From Greenland, joined Feb 2004, 17036 posts, RR: 67
Reply 21, posted (7 years 2 months 4 days 9 hours ago) and read 8408 times:

Quoting Malaysia (Reply 12):
Quoting Alias1024 (Reply 11):
You wouldn't want your raft to float away before the passengers got into it either.

But I can swim to it

You can swim. But how about young children, the elderly, parents carrying infants?

Quoting Flybyguy (Reply 7):
not only because I don't believe that a water landing by a commerical airliner is structurally survivable

Water landings where the plane has remained intact have occurred on many occasions.



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlineTristarSteve From Sweden, joined Nov 2005, 4003 posts, RR: 34
Reply 22, posted (7 years 2 months 4 days 9 hours ago) and read 8410 times:

Quoting OPNLguy (Reply 1):
In the event of a water evac, there's a line associated with each overwing exit that is extended, and clips to that yellow bracket, as a guide to get everyone out on the wing.

The first reply was correct, then we get lots of theories!
The B737 has no slides or rafts associated with the overwing exits. You are meant to climb onto the wing and slide down the flaps. In theory the first pax out should take the rope and attach it to the yellow ring to stop people falling off the front of the wing. I wonder if it has ever happened, except in a demonstration?


User currently offlineUSCGC130 From , joined Dec 1969, posts, RR:
Reply 23, posted (7 years 2 months 4 days 8 hours ago) and read 8390 times:

Quoting Starlionblue (Reply 21):
ou can swim. But how about young children, the elderly, parents carrying infants?

Even an able-bodied adult wouldn't want to get wet if he could avoid it, since it could result in hypothermia. Or extreme discomfort while waiting for rescue, at the very least.


User currently offlineHAWK21M From India, joined Jan 2001, 31679 posts, RR: 56
Reply 24, posted (7 years 2 months 4 days 7 hours ago) and read 8369 times:

Its For attaching the Emergency exit Lanyard to help as a hand hold in Evacuation & can be used as a Raft hold.

Quoting Malaysia (Reply 10):
I wouldnt want to hook my raft to the wing when the plane starts to sink

Ever heard of Shear point in a Rope.That shears off when excessive loaded.

regds
MEL



Think of the brighter side!
25 MarkHKG : Actually, some carriers suggest sliding off the LEADING edge of the wing on the B-737 as they believe a ditching would severely damage the flaps and
26 Starlionblue : Agree completely.
27 Post contains images MarkHKG : This is really NOT an ideal solution, but air carriers suggests on aircraft without slide/rafts (i.e. B737, MD-80, some A320 aircraft) that "frail or
28 Starlionblue : Expletive! Remind me never to be in a ditching with my daughters...
29 TZTriStar500 : This is the attach point for the life line which is a requirement of 14 CFR Part 25.1411 for ALL aircraft certified for ditching with an overwing exit
30 Post contains links Viscount724 : It was actually a river. In 1968, a JL DC-8-62 landed in San Francisco Bay a couple of miles short of the SFO runway in foggy conditions. Fortunately
31 Post contains links MarkHKG : Let's also not forget the China Airlines B-747-400 which overran the runway at Hong Kong Kai Tak International Airport, which in my recollection is th
32 HAWK21M : That stayed afloat for quite some time. regds MEL
33 Greasespot : Tha above three have it...The ring is for a line that the first pax is supposed to extend out....It has nothing to do with rafts at all... One last t
34 OPNLguy : He didn't say there was a slide (used as a noun) associated with the overwing exit--he mentioned sliding (used as a verb) down the L/E of the wing, o
35 Post contains images MarkHKG : If life-rafts are to be deployed from the wing, the attached life-line (I never referred to the attachment point) CAN be used as an attachment point
36 Flybyguy : I hope that an Ethiopian 767-200 was not one of those ditching efforts, it was torn to pieces the moment it hit the water. I know GA planes have ditc
37 Post contains links MarkHKG : It wasn't really a controlled ditching considering that the hijackers tried to take control of the powerless aircraft in the last few moments before
38 Starlionblue : This attempt doesn't really "count". As MarkHKG mentions, it was not very controlled. As the plane was about to ditch, the hijackers tried to take co
39 HAWK21M : Which Carriers are you reffering to. regds MEL
40 MarkHKG : Republic Airlines is one. Many corporate jets also recommend the leading edge (Gulfstream, Falcon, Global Express, etc.) .
41 HAWK21M : Does Republic operate B737s or only Emb 170s. regds MEL
42 MarkHKG : They use to operate MD-80s. Similarly, Canadian Airlines recommended on their 737s to jump from the leading edge in a ditching, but they don't exist
43 WNCrew : You know, it amazes me how many pilots aren't even aware of the crash history of aircraft. I've had MANY tell me there was never a successful ditching
44 Starlionblue : In a way, sure. I will agree that it shows a certain education to know some history of what you work with. But then again is knowing the history real
45 WNCrew : Honestly, When YOUR job is the safety of passengers and being familiar with MANY possible situations I say yes, it is important that you know the his
46 HAWK21M : True.I've spoken to many Flight crew,who though very good in their job are not very well versed about the Aviation world.Guess its an Individuals int
47 ThirtyEcho : Thank God for those life raft tiedowns on WN B737s!!! For many years, I have been worried about a water landing in Bachman Lake off the arrival end of
48 Starlionblue : Sure, but you didn't say crash history. You were mentioning examples like the entry into service date of the 320. Is the latter really important to o
49 Post contains links and images IFixPlanes : ... and the answer is:
50 BHMBAGLOCK : It's odd to me that this is not mentioned in the exit row briefing on any airline that I've flown. I've probably been in the exit row of a 737 at leas
51 MarkHKG : You're right, carriers typically do not mention it, but they do ask you to look over the safety card as part of the exit row briefing -- and these ca
52 Post contains images MarkHKG : Okay, that came out weird. "You, take this clip and attach it to the hook on the wing. Step out, foot first, inflate your vest!" There, that was the c
53 Srbmod : Asked and answered. Thread locked.
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