Why aircraft door edge painted with different color?

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The purpose of painting an aircraft is to provide pleasant appearance. Apart from this, protect the integrity of airframe against corrosion and deterioration. Airlines operator usually select two- or three-color combination for painting of an aircraft. Out of these two or three colors one of the colors is majority use for painting an aircraft such as white paint. Due majority use of one color on most parts of aircraft, sometimes it’s difficult to locate different parts of an aircraft specially for rescue crew in crash condition.


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Have you notice thick solid line on the edge of passenger door or emergency exit door? The color of this thick solid line is different from aircraft door color. The purpose of painting of aircraft door edge with single solid line is to easily locate and open door quickly in emergency condition by rescue crew.





Fig 01 Solid Line Color on Door
          


In the past, several aircraft accident happened. Many lives of passengers could not save because the same color of fuselage and door, rescue crew outside of an aircraft were unable to quickly find aircraft door and emergency exit in dark and thick smoke after a crash.  Thus, after several crash regulator has changed aircraft color scheme design to prevent such occurrence. 

The regulator set rule for painting of all commercial aircraft. The regulator rule which said that all commercial aircraft must have passenger door, crew door, Service door and emergency exit door identified by two-inch-wide solid stripe of color on periphery that contrast with surrounding color of fuselage or door. The contrasting outlines of door allow to find door quickly. Today, airlines designer have integrated mandatory aircraft door solid stripe into overall color scheme of  an aircraft with much more suitable color that suite the airline brand.  



Fig 02 Solid paint line on Passenger crew door




Fig 03 Solid Paint line on emergency exit


 The following is the regulator statement for painting of aircraft door as per 14 CFR Rule ;


14 CFR § 25.811 Emergency exit marking.


Each emergency exit that is required to be openable from the outside, and it's means of opening, must be marked on the outside of an airplane. In addition, the following apply:

(1) The outside marking for each passenger emergency exit in the side of the fuselage must include a 2-inch colored band outlining the exit.

(2) Each outside marking including the band, must have color contrast to be readily distinguishable from the surrounding fuselage surface. The contrast must be such that if the reflectance of the darker color is 15 percent or less, the reflectance of the lighter color must be at least 45 percent. "Reflectance" is the ratio of the luminous flux reflected by a body to the luminous flux it receives. When the reflectance of the darker color is greater than 15 percent, at least a 30-percent difference between it's reflectance and the reflectance of the lighter color must be provided.



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Comments

  1. UnknownJuly 24, 2021 at 5:36 PM

    Really a nice to know info. Properly explained with reference. Thank you for this post ☺️

    ReplyDelete

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