BMI727 From United States of America, joined Feb 2009, 15739 posts, RR: 27
Reply 2, posted (4 years 4 months 14 hours ago) and read 7267 times:
Quoting 474218 (Reply 1): The randoms and cowling are interchangeable. So they have been removed from one aircraft and installed on another.
I think that in at least some cases the radomes are detached and painted separately, which is how one got turned upside down and ended up on a UA plane. Also, it isn't uncommon to see radomes in completely different schemes on regional planes which of course keep a common spares inventory.
Why do Aerospace Engineering students have to turn things in on time?
RoseFlyer From United States of America, joined Feb 2004, 9635 posts, RR: 52
Reply 5, posted (4 years 4 months 13 hours ago) and read 7180 times:
Quoting kanban (Reply 4): initially all painting is indexed to water line zero
To add some explanation to that, there is a three dimensional grid to which airplanes are built with waterline and stationline being used to index paint. While they are not labeled on the outside of the aircraft, each of the points are identifiable and can be used for reference.
If you have never designed an airplane part before, let the real designers do the work!
Can someone explain how painting/preparation begins at these points. Where are these points usually located?
How are radomes painted seperately if, like on some liveries, you have to line up the stripes exactly?
The following may help in understanding "Water lines/Butt lines/Fuselage Station lines:
Water lines, start below the surface and extend up. Example: the ground is waterline 19 (19 inches above WL 0), the cabin floor is WL 200 (181 inches above the ground).
Butt lines start at the center of the fuselage and extend out left and right. Example BL 0 is the middle of the fuselage the outer fuselage skin is BL 115 left or right (or 115 inches from the middle of the fuselage).
Fuselage Stations start forward of the nose run to the end of the fuselage. Example FS 83 is the tip of the radome, FS 2215 (or 2132 inches from the radome) is the end of the fuselage.
As you can see by the lists of abbreviations there are may other parts that have their own station lines.
rolypolyman From United States of America, joined Mar 2009, 159 posts, RR: 0
Reply 10, posted (4 years 4 months 4 hours ago) and read 6907 times:
I'm actually wondering how they get the logos, shapes, and polygons painted so precisely... do they spray against plastic stencils? I can't even picture how a painter decides exactly where to hold the stencil and at what angle. If I was given a 777 to paint, I'd take an LCD projector and cast a template against the fuselage to use as a guide and use that with stencils. Funny how the whole process is so mysterious.
Because the rudder is balanced. So it is painted and balanced before being fitted to the airframe. Then it is masked and then the rest of the airframe is painted. Most of the time the ailerons and elevators get the same treatment.
Mender From United Kingdom, joined Feb 2004, 240 posts, RR: 0
Reply 20, posted (4 years 3 months 3 weeks 5 days 10 hours ago) and read 5799 times:
Quoting rolypolyman (Reply 10): If I was given a 777 to paint, I'd take an LCD projector and cast a template against the fuselage to use as a guide and use that with stencils. Funny how the whole process is so mysterious.
How far away from the aircraft would you have to place you LCD projector? Would it be bright enough to be visible when it's that far back? Think about this as well. If you have a 1" mis-match on a 100" surface you only have an error of 1%. Whilst a radome may not be 100" high I bet it's at least 50" and 1" in 50 is only 2%
I'm not trying to ridicule you, I'm trying to point out it's not as easy as it first seems.
Even if you were to use a laser you'd have to ensure the first aircraft was exactly as high as the second aircraft or have a trick laser. In a manufacturing environment you could do this but it would be a lot harder painting an Airbus then a Boeing back to back.
tdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 79
Reply 21, posted (4 years 3 months 3 weeks 5 days ago) and read 5691 times:
Quoting Mender (Reply 20): Even if you were to use a laser you'd have to ensure the first aircraft was exactly as high as the second aircraft or have a trick laser.
No need for constant height, just need known reference points on the aircraft so the laser knows where it is in relation to the aircraft. Then it can project any shape on to any surface with very high accuracy, assuming it's got line-of-sight. Fortunately, aircraft are full of known reference points already (jack pads, major structure points, tooling references, etc.), so it's just a matter of choosing which one(s) you want to stick the laser marker on.
Quoting Mender (Reply 20): In a manufacturing environment you could do this but it would be a lot harder painting an Airbus then a Boeing back to back.
Why? As long as your laser system knows the geometry or each aircraft (which was a prerequisite to using the laser in the first place), it doesn't care.
AirframeAS From United States of America, joined Feb 2004, 14150 posts, RR: 24
Reply 22, posted (4 years 3 months 3 weeks 4 days 22 hours ago) and read 5661 times:
Quoting boeing767mech (Reply 14): Because the rudder is balanced. So it is painted and balanced before being fitted to the airframe. Then it is masked and then the rest of the airframe is painted. Most of the time the ailerons and elevators get the same treatment.
I want to clarify boeing767mech's explanation.... This is done on the Boeing aircraft. Airbus does not balance their rudders, hence why you see a full tail painted on a brand new airplane vs. only rudder is painted on a Boeing aircraft.
A Safe Flight Begins With Quality Maintenance On The Ground.