View Full Version : Replaceing cockpit window.

Captain Vortex
1st Mar 2002, 03:31
Does anyone know the correct procedure for replaceing a fwd cockpit window of a B737?. .How long time does it take, and can you fly with it broken or cracked.

1st Mar 2002, 04:12
Captain Vortex,. .The correct procedure for replacing a B737 flight deck forward window will be in accordance with the relevant aircraft maintenance manual. . .I'm no expert on the B737, but in comparison to types I'm familiar with, I think its unlikely that you can fly with it broken or cracked. The only defect usually allowable on windscreens are delaminations and they are only allowable within MM limits.. .Regarding time to change a windscreen; well, a good engineer SHOULD take as long as is necessary to ensure that the replacement is carried out IAW the MM and be properly certified.(Remember the BA BAC1-11?) However, usually you have managers/despatchers/passengers/accountants looking over your shoulder providing "commercial" pressure and therefore the time factor is down to the professional integrity of the engineer.

1st Mar 2002, 05:02
You can fly with the window craked or delaminated. If you have a look at 737 QRH, there is a checklist called "arcing, delaminated or cracked window". But the MEL, of course will not let you leave with the window not even delaminated...!

But yes, you can fly... Hoe long to replace? Never been trought that, and don`t know someone who has, so I really don`t know, but it`s a good question for an engineer!


1st Mar 2002, 07:31

As usual the time it takes to change a window depends on who changed it the last time. A correctly installed window will have underneath the aerodynamic seal a piece of string. You dig the end of the string out and pull it to break the rest of the seal. If this has not been done it will be a ****** to break the seal without damaging the surrounding structure, so will take a lot longer.

Time to change it also depends on the local weather. It will be easier and quicker if it is a nice 18 degs C and dry, than if it is 2/3 degs C and raining. We have changed a window here in about 4 hrs. However time should then be allowed for the new sealant to cure (the MM allows for the application of speed tape over the sealant to prevent it splurging all over the a/c) and the window will have to be retorqued several times over the following days.

Contrary to a previous post you CAN fly with a delaminated window (usually only within an inch or two of the edge as these are not considered to structurally degrade the window) The a/c MM will clearly define the various limits, and to my surprise according to our MEL are able to fly with one cracked!!??

'FWD (#1) window outer glass ply may be cracked provided :-

Visibility is acceptable to the captain and the remaining window has clear visibility.

Airspeed is limited to 280kts below 10000ft

The a/c may continue the flight or series of flights not to exceed 1 flt day prior to repairs

(obviously a get you home MEL item)

Hope that helps.


1st Mar 2002, 12:59
I agree about the "bring you home MEL item" with the addition of one small detail: There will be NO Passengers on this flight!!!

----------------------------------------------. . [quote]Err. What does this button do?<hr></blockquote>

oops. Just found out!

1st Mar 2002, 18:50
The correct procedure for replacing a fwd cockpit window on a B737 will be found in the Boeing Aircraft Maintenance Manual for the B737-? model specific.. .As to how long it takes to change one, several hours, also to be considered is the removal/refit of the roof trim, glare shield panel, the best part of the instrument and autopilot panels and function tests required for these.. .Aerodynamic sealant cure can be aided by the use of short working life versions, heat and hi-speed tape as per AMM.. .The MEL, these are company/regulatory authority specific from the MMEL. So quoting what is allowable for one operator maybe different for another. . .As to the comment about the BAC1-11/B737 windshields earlier, the B737 windshield is mounted inside the flt deck window frame.

[ 01 March 2002: Message edited by: All That Glitters ]</p>

4th Mar 2002, 03:15
Mono- just for info I dont think the manual states that a retorque is needed in the next few days as you could go around torquing the screws forever! (ie torque opposite sides.) the manual does state that the window beds in and if required may be re torqued later). .If you follow the pattern suggested in the manual this is good enough.. .If anyone has changed a fwd window in 4 hours- that was working extremely well! I have never come across a window that anyone had actually bothered to put the cord in as well! The biggest pain is the trim and MCP etc, which of course needs full functions afterwards.

5th Mar 2002, 09:41
You can fly 737 with a cracked windscreen. MEL also release for flight provided it's the outer pane which is crack.. .The inner and middle pane cracked is much more restrictive.

GE 90
6th Mar 2002, 02:34
737 windscreens are a real pane in the preverbial. The actual windscreen is a doddle being the same as a 707 but to get to it does require starting just fwd of the seats and dismantaling towards the radome.. .You can't have the same problem as was experienced by the 1-11 skipper who took evasive action when the steward got too friendly as it is fitted from inside the frame. (Gets pushed into frame the more you pressurise.) It also has lose nuts so they can be replaced with fresh ones. . .As for time taken. Anything up to 8 hours depending on sealant. By the way the speed tape is there to stop the "not fully cured" sealant from being blown over the new screen and is removed 24 hours later.. .Most other a/c have screens fitted from the outside and need greater care that the correct bolts and torque figures are used. It does mean they can be changed much quicker.. .Delam is allowed provided it doesn't cause the heating to fail and does not impair vision. Without the manual to hand I seem to remember 2 inches max but that could be DC10.