I'm getting ready to get N numbers and wondering how much contrast there needs to be for the background. I have a darker background and wondering if black would not be enough contrast ? I know that is pretty relative but what is the rule of thumb, is it distance or is it just up to the DAR?
Van's Air Force
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N number contrast
- Thread starter rvdave
- Start date
Your answer can be found in the FAR's
az_gila
Well Known Member
Not really...
A snippet of the FARs...(c) Aircraft nationality and registration
marks must?
(1) Except as provided in paragraph
(d) of this section, be painted on the
aircraft or affixed by any other means
insuring a similar degree of permanence;
(2) Have no ornamentation;
(3) Contrast in color with the background;
and
(4) Be legible.
I would say quite a bit is subjective and would be ruled on by the DAR...
And that there is the problem with this type of thing..... it is not our opinion that matters.
Line 4 says - Be legible.
Being legible is influenced by the level of contrast.
What it really comes down to is what level you are willing to risk an expensive redo on a paint job you might have already paid a lot of money for, because an airworthiness inspector saw your airplane and decided to make a case that in his opinion it is not in compliance (I have been involved in this type of situation... it is a pain), and designates the airplane un-airworthy until corrected.
More on "N" numbers from various sources
From AOPA: https://www.aopa.org/training-and-safety/pic-archive/aircraft-ownership/airplane-n-number-markings
Location of N-number: http://www.flightsimaviation.com/data/FARS/part_45-25.html
Size of markings: http://www.flightsimaviation.com/data/FARS/part_45-29.html
From AOPA: https://www.aopa.org/training-and-safety/pic-archive/aircraft-ownership/airplane-n-number-markings
Location of N-number: http://www.flightsimaviation.com/data/FARS/part_45-25.html
Size of markings: http://www.flightsimaviation.com/data/FARS/part_45-29.html
from AC 45-2E
7.3 N-Number Legibility.
The N-number is required to be legible and written in capital Roman style letters
without any ornamentation. You may use shading or a border only if it makes the
number more legible. Use the following guidelines:
7.3.1 Make sure the color contrasts sufficiently with the color of the fuselage to make it
easy to read. Be especially careful when the background is highly decorated, as in
checkering. Consider applying the requirements of 14 CFR 23.811(c)(7)(ii) or
14 CFR 25.811(f)(2), Emergency exit marking, as a test of whether the color of the
N-number contrasts sufficiently with the background.
7.3.2 Check the reflectance of external markings. Using electro-optical instruments or
photometer card sets is an acceptable means of verifying reflectance, but these
instruments are not required to establish reflectance. The FAA considers a 12-inch
number legible if you can read it from 500 feet away, in a horizontal line, and
perpendicular to the side of the aircraft during daylight hours, without using an optical
aid such as binoculars.
7.3.3 If you question whether an N-number is legible, because of either color or reflectance,
check with your local FAA inspector.
From FAR 23.811(c)(7)(ii)
(ii) Have a color contrast that is 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 its reflectance and the reflectance of the lighter color must be provided.
7.3 N-Number Legibility.
The N-number is required to be legible and written in capital Roman style letters
without any ornamentation. You may use shading or a border only if it makes the
number more legible. Use the following guidelines:
7.3.1 Make sure the color contrasts sufficiently with the color of the fuselage to make it
easy to read. Be especially careful when the background is highly decorated, as in
checkering. Consider applying the requirements of 14 CFR 23.811(c)(7)(ii) or
14 CFR 25.811(f)(2), Emergency exit marking, as a test of whether the color of the
N-number contrasts sufficiently with the background.
7.3.2 Check the reflectance of external markings. Using electro-optical instruments or
photometer card sets is an acceptable means of verifying reflectance, but these
instruments are not required to establish reflectance. The FAA considers a 12-inch
number legible if you can read it from 500 feet away, in a horizontal line, and
perpendicular to the side of the aircraft during daylight hours, without using an optical
aid such as binoculars.
7.3.3 If you question whether an N-number is legible, because of either color or reflectance,
check with your local FAA inspector.
From FAR 23.811(c)(7)(ii)
(ii) Have a color contrast that is 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 its reflectance and the reflectance of the lighter color must be provided.
