"Cy Galley" wrote in message
news:ifMre.51056$_o.26541@attbi_s71...
When did this come about? When the lettering wears off?

It's in the F.A.R.'s, Cy. I carry a copy of the applicable sections in the
Emeraude for the express purpose of showing EAA judges that it is NOT
required on a homebuilt of a certain design date and/or one of the same
external configuration.

Look it up in F.A.R. 45.22 for the full wording. Here are the key sentences
with added emphasis:

45.22 Exhibition, antique, and other aircraft: Special rules.

(b) A small U.S.-registered aircraft built at least 30 years ago or a U.S.-
registered aircraft for which an experimental certificate has been issued
under Sec. 21.191(d) or 21.191(g) for operation as an exhibition aircraft or
as an amateur-built aircraft and which has the same external configuration
as an aircraft built at least 30 years ago may be operated *without* repeat
*without* displaying marks in accordance with Secs. 45.21 and 45.23 through
45.33 if:

(1) It displays in accordance with Sec. 45.21(c) marks at least 2 inches
high on each side of the fuselage or vertical tail surface consisting of the
Roman capital letter "N" followed by:
(i) The U.S. registration number of the aircraft; or
(ii) The symbol appropriate to the airworthiness certificate of the aircraft
("C", standard; "R", restricted; "L", limited; or "X", experimental)
followed by the U.S. registration number of the aircraft; and
(2) It displays no other mark that begins with the letter "N" anywhere on
the aircraft, unless it is the same mark that is displayed under paragraph
(b)(1) of this section.

The following section is included for your reference. Note that it is *not*
applicable under the foregoing section.

45.23 Display of marks; general.
(a) Each operator of an aircraft shall display on that aircraft marks
consisting of the Roman capital letter "N" (denoting United States
registration) followed by the registration number of the aircraft. Each
suffix letter used in the marks displayed must also be a Roman capital
letter.
(b) When marks that include only the Roman capital letter "N" and the
registration number are displayed on limited or restricted category aircraft
or experimental or provisionally certificated aircraft, the operator shall
also display on that aircraft near each entrance to the cabin or cockpit, in
letters not less than 2 inches nor more than 6 inches in height, the words
"limited," "restricted," "experimental," or "provisional airworthiness," as
the case may be.
[Doc. No. 8093, Amdt. 45-5, 33 FR 450, Jan. 12, 1968, as amended by Amdt.
45- 9, 42 FR 41102, Aug. 15, 1977]

I seem to remember at Oshkosh '99, they were celebrating the 25th.
anniversary of the first RV. That would make it 31 years ago. I'm sure Unca
BOb knows exactly when the RV-3 was released. The RV-4 can't be far behind.

Rich S.