I get a lot of interesting comments when people see the registration number on my plane. Everything from, “Way cool” to, “you better hope the FAA doesn’t see that.” I get a chuckle out of the later one. I think that this is one area of homebuilding that the feds don’t make a huge deal about unless there is way too much artistic license taken. Just take note of all the variations of registration numbers on the planes at Oshkosh and you will ask how they got away with that.
Just over a year ago, I had my vinyl-wrapped RV-7 painted at Art Craft Paint in Santa Maria, CA. When I showed them the paint scheme and how I wanted my N number to be, two different colors, they questioned if I could get away with it. “Of course,” I said. “It’s done all the time.” I actually wasn’t sure. I figured that if it was not a legal marking, surely a paint shop would know. Fortunately, I had several weeks before the paint shop was ready to put the red and silver on the plane and I took that time to research what is and isn’t allowed on an “N” number. During that time, I saw the gorgeous RV-10 that was being given away by AOPA with the N number N260MG with the contrasting 0MG. Very cool in my world. By the way, do you ever say, “N number” and get that feeling that you’ve said something redundant like ATM Machine, or VIN Number? I digress.
FAR Part 45 gives all the detail for size and location of the N number including this:
§ 45.21 General.
Except as provided in §45.22, no person may operate a U.S.-registered aircraft unless that aircraft displays nationality and registration marks in accordance with the requirements of this section and §§45.23 through 45.33.
Unless otherwise authorized by the Administrator, no person may place on any aircraft a design, mark, or symbol that modifies or confuses the nationality and registration marks.
Aircraft nationality and registration marks must—(
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; (ie: paint or decal)
Have no ornamentation;
Contrast in color with the background; and
For most of us, we can look to the much easier-to-understand Advisory Circular (AC) 45-2E.
AC 45-2E covers the required markings for aircraft, engines, and propellers including what your ID plate must have on it and where it is placed as well as the EXPERIMENTAL or Light Sport markings. Here is some if the information:
Minimum height: 12 inches (with exceptions such as exhibition, limited or restricted category aircraft).
Location: (1) On both surfaces of a single vertical tail or on the outer surfaces of a multi-vertical tail, or (2) On the fuselage surfaces, on both sides of the fuselage between the trailing edge of the wing and the leading edge of the horizontal stabilizer. If engine pods or other equipment are located in this area and are an integral part of the fuselage side surfaces, you may place the marks on those pods or equipment.
Minimum Height: Exhibition, amateur-built, and light-sport aircraft with a maximum cruising speed of 180 knots or less 3 inches (with exceptions as shown in Table 3).
Location: (1) On both sides of the fuselage between the trailing edge of the wing and the leading edge of the horizontal stabilizer, or (2) On both sides of the vertical tail surface.
Orientation: Horizontal (with exceptions as shown in Table 3)
These are just two of the several aircraft types or categories AC 45-2E covers, and they're also examples of exceptions from the rules including this last item in the table:
Displaying an N-number on an aircraft, but not as specified in this AC. You may ask the FAA for authority to display the number in some other way. Contact your local FSDO or MIDO for assistance.