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-   -   Boeing aircraft "eyebrow" windows (https://www.pprune.org/tech-log/151720-boeing-aircraft-eyebrow-windows.html)

eal401 11th November 2004 07:29

Boeing aircraft "eyebrow" windows
 
Possibly the wrong forum, I'm not sure.

A page on the Boeing website suggests that they have removed the eyebrow windows on the 737.

http://www.boeing.com/commercial/737family/flash.html

Elsewhere they have done the same for the 717.

Any idea why? Moreover, what was the purpose of the windows in the first place?

itchy kitchin 11th November 2004 07:40

Pity, I thought the windows made the 'plane look "cool" and "hard"

what are they for? to see out of, of course!

ironbutt57 11th November 2004 08:03

Can ya reelly see out ofthem, or are they just there to give bald pilots a bit more exposure to radiation?:}

Kerosene Kraut 11th November 2004 08:04

It might save a slight bit of weight, production and mx cost. And most important having a glass cockpit you don't get blinded by straight sunlight from the top anymore. Tight VFR patterns are rarely flown where eyebrow windows still come in handy.

However don't know if the 737 are set to lose their's.

ZQA297/30 11th November 2004 09:52

Hah! You see! The thin end of the wedge.
It is only a matter of time before no windows at all, think how much that would save.

RichT 11th November 2004 10:13

Actually the windows were for astral navigation. Not much use any more.

ferrydude 11th November 2004 10:13

KK is on target, they were eliminated to safe weight and cost.
Originally intended to be used to view the stars for navigation, and turned out to be quite handy for those visual approaches and steep turns, sad to see them going. FD

RAT 5 11th November 2004 11:14

Visual approaches containing steep turns? Now there's an interesting concept. Fun, Fun! (extracting tongue from cheek....)

I must admit to never having looked through them, except to see the horizon approaching the top of the loop. (Ah! tongue still in cheek....) The B707 only did a barrel roll I remember.

Astro Nav? & where did the Nav sit? Ah, that's what they meant by the 'observers's seat'. Didn't the B737 come after the B727? and was it really contemplated that these a/c, with no nav, would fly in areas requiring astro? I admit, all before my time; just curious.

However, can't remember ever looking through them doing visuals, even tight ones. Usually impossible, anyway, because someone, before tailored sun screens arrived, had stuffed maps or newspapers to block out the sun.

A sun roof would have been useful on some RH circle patterns from the LHS in B767's, though.

GearDown&Locked 11th November 2004 11:20

From what is shown on Boeing website that info is probably not accurate; see this .

B737NG 11th November 2004 11:21

No Eyebrows on the B737 anymore is just like on then B757,767, 777.....
Save productioncosts... that is the task.

NG

eal401 11th November 2004 11:27


From what is shown on Boeing website that info is probably not accurate;
Er, my original post is based on a picture on the, um, Boeing website. :\

Check my link again?

ferrydude 11th November 2004 12:06

Who said anything about visual approaches containing steep turns? The post was, "visual approaches AND steep turns". Regardless, I suppose you never had the pleasure of the visual approach to Kai Tak.

QNH1013 11th November 2004 13:37

I'll admit, I never view anything out of the eyebrow windows except to catch a little bit more of the view of a beautiful aircraft flying directly over us in the opposite direction. Mostly, at certain times of the day the eyebrow windows my side are all covered with the last pages of the notams to block the sun from shining right at me :O

oceancrosser 11th November 2004 14:16

I think eyebrow windows are actually a relic from the past. Used to fly the DC-8 with quite big ones, usually stuffed with something to keep the sun out like others have written here. Same thing on the B737s I flew, tailored sunshades were some help though. The original 707 had them (same nose section as the 727,737 therefore...) but I always guessed that was some kind of military relic due to Boeings planned (and successful) military use of 707 derivatives. Perhaps former military guys know? Something originally to do with formation flying? Or as suggested here tight circuits?

DownIn3Green 11th November 2004 14:47

On the B-727, the eyebrows were there for certification reasons. The pilots had to have certain angles of vision for various flt regiems.

2FLYEU 11th November 2004 15:19

From the RH seat, the Capt. side eyebrow window it's very useful when turning from downwind to left base especially on tight turns...
It gives a good glance of the rwy.

Also gives the 73 a very "nice but tough" look.

happy landings !!!

The Greaser 11th November 2004 15:21

I wish they would get rid of them in the 73. They are of no practical use whatsoever and just help turn the flightdeck into a sauna and solarium in one.

TR4A 11th November 2004 17:34

We have been hearing no eyebrow windows on our B737-7H4's next year. I think Boeing finally convinced the FAA that they were really not needed.

Sqwak7700 11th November 2004 18:39

Well, not that it matters, but someone told me that they were for certification. The flight deck was kind of dark during the day without them, so Boeing installed them to make it brighter in there.

Makes sense when you think of it. The forward and side windshields on aircraft with Eyebrow Windows (707,727,737,DC-8,DC-9,MD80) are really tiny. I could see how it would be hard to see the steam-gauge instruments during the day. With the advent of Glass Cockpits, seeing the instruments is not really a factor, unless it is in direct sunlight. So now you want less light, not more. Pretty funny if you ask me.

I think Boeing realized this on 717, finally designing them out cause we don't need them. I've never flown the 737, but I would guess that they are definetely more expensive and heavier than just a metal plug. I wouldn't be surprised if the FAA also requires them to be heated since thay are a window. Soemone then had the bright idea of removing them on the 73 line, which makes perfect sense. A cost and a weight savings.

SeniorDispatcher 11th November 2004 19:25

>>>However don't know if the 737 are set to lose their's.

Actually, very soon. Starting in January 2005, Boeing will start delivering 737-700s to Southwest without eyebrow windows. N200WN will be the first...

bafanguy 11th November 2004 20:59

Flew the 727, 737, DC9, MD88...never saw a use for eyebrow windows. I did, however, see a DC9 eyebrow overheat, turn brown and peel open like a banana. Wish a had a video...

Flight Detent 12th November 2004 01:35

Hi all,

On the military versions of the B737, for AEW&C and MMA, the eyebrow windows will be used during the maneuvering for air-to-air refueling, though when the airplane is approaching and in the correct position, the pilot can see the line-up points and fuel boom through his main #1 window.

The eyebrow windows are needed to increase visual coverage to suit any eventually.

FD:cool:

Taikonaut 12th November 2004 05:03

Here's another take.

During the original certification of 727 (late 50s??), they have to have so much "window" area in the cockpit and to widen the existing cockpit would have weaken the structure so they put the little windows in. Hence the "combined" window areas would meet and pass the certification requirements. They did away with that when 747 came around.

Heard it from some engineer a long time ago so don't quote me on it. :}

Probably the same folks that put the stupid little mirror in the 747 cockpit so that you can see the flap position from the left seat, albeit upside down. :hmm:

nitefiter 12th November 2004 08:26

Firstly i must apologise in advance for posting slightly off topic and i dont want to nick the thread, but whilst there are so many 737 experts out there,i want to ask "Why do 737,s seem to crab whilst taxiing"? Serious question im starting a course soon.
PS I have heard all the jokes!!

Nineiron 12th November 2004 23:01

Eyebrow windows very useful lookout if you are on the outside of the bend during a circling approach.
Wasn't there a long running thread on crabbing 737s a while back?
Quidnunc came up with "The main wheels have 2 - 3 degrees left/right play in them, so if the a/c lands in a cross wind the mains may be out at their limit. When taxying it then appears that the a/c is crabbing. The wheels are straight straight down the taxy way, but the fuselage looks (and is) a couple of degrees out of alignment."
Sounds feasible

nitefiter 13th November 2004 08:27

thanks, ill try to find that thread and have a look,thats what i was led to beieve but i cant find any reference to it in my manuals

BOAC 13th November 2004 08:35

nitefiter - it is not in any 'manuals'. Type '737 crab' into pprune search.

autoflight 13th November 2004 12:51

Many years ago I was told that the B52 had these eyebrow windows & that subsequent Boeings automatically followed this design.

rubik101 13th November 2004 13:19

look out!
 
Bearing in mind that the B707 was initially produced and designed as a military aircraft it is hardly surprising that the windows were installed there. Future plans for AtoA refuelling would have been extremely costly if they had to put the windows in later. 727, 737 etc. are just inheritors of the original design. Simple really!

Dr Illitout 14th November 2004 08:11

I was told that the No's 4 +5 windows were fitted to the origanal kc135 to allow the Pilot's to see the lower fuselage markings/lights on the tanker aircraft during flight refueling. As the forward fuselage on the Kc-135, 707, 720, 727 and 737 is basicaly the same, they were left in.
On a personal note they are a pain in the ar*e to change and should have been removed a long time ago!

Rgds Dr.I.

nitefiter 14th November 2004 08:23

BOAC
Thanks,done it.

BusyB 14th November 2004 14:46

A H/S test pilot used to demonstrate circuits in Tridents with the RWY in his eyebrow window from downwind. Very sporting!

TURIN 16th November 2004 13:31

nitefiter.

The previous threads on this crabbing lark are not quite right.

The crab effect IS due to the main gear having a couple of degrees of play in them due to the shimmy dampers.

However my understanding is that the dampers are there to stop the shimmy, not to allow crosswind landings.

If the dampers have leaked fluid or are not bled correctly then the aircraft shimmys quite badly. :ok: A regular nightshift job in the rain that one- bleeding the shimmy dampers! :ugh:


Back to the thread..

I thought the 757 fuselage was also based on the 727. Were the eybrow windows removed then for the glass cockpit?:ok:

oceancrosser 17th November 2004 14:03

Turin,

The 757 fuselage is more or less the same tube as the 737,727,707...

Initially the 757 development drawings showed the "standard" Boeing narrowbody nose. Even a T-tail was contemplated.

However when the commonality with the 767 came about (it was not a design criteria from the outset) the nose and window shape was designed so as to allow the commonality and a similar view from both flightdecks. And very successfully. Good looking airplane.

TURIN 18th November 2004 20:16

oceancrosser

You're right! I have just found a picture of the original launch model of the 757 from 1978. Sure enough T tail and eyebrow windows. Nice one.:ok:

Source: "A HISTORY OF PASSENGER AIRCRAFT! by William Sweetman.

tommytill 19th March 2005 07:22

eyebrow windows
 
They are handy for visual reference when Air to Air refuelling...

Touch'n'oops 19th March 2005 07:32

I covered this one ages ago, but for all you lot who missed it!!!

http://www.boeing.com/news/releases/...q1/050126h.jpg


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