Homebuilt Serial Number

[Clarke Tate]

I am interested in how the serial number works on a homebuilt project. Some plans I have purchased come with a plans serial number, others have no such serial number. How does this work for plans with no serial number assigned to a design?

[rwanttaja]

I am interested in how the serial number works on a homebuilt project. Some plans I have purchased come with a plans serial number, others have no such serial number. How does this work for plans with no serial number assigned to a design?
The builder is the manufacturer, and thus assigns any serial number they wish. Plans or kit sellers sometimes assign serial numbers, but the builder is not obligated to use those when licensing the aircraft.

Pete Bowers used to put a serial number on each set of Fly Baby plans consisting of the year and a sequential number within that year ("67-10"). But here's a random sample of the actual serial numbers some Fly Babies ended up with:

68-48
63-62
1-65
64-1
GIF-1
67-24
64-11
NRG1
918
4878
1
1000
65-44
70-9

The FAA registration database shows about 1500 homebuilts of all types listed as Serial Number 1, and another 1500 or so listed as variation on that (0001, 001, 01, etc.). There are, for instance, 13 RV-6 aircraft listed as "Serial Number 1". Again, it's up to the builder; the plans serial number (or lack thereto) doesn't make a difference.

Ron Wanttaja

[Joda]

The only requirement is that you cannot have duplicate serial numbers under one builder name. So for builder "John B Smith" you could not use serial number "002" or whatever more than once. Other than that, you can assign whatever serial number you want. The FAA suggests that you use your plans or kit serial number, but you are not required to do so.

[FlyingRon]

You can always use your intended N number as well. One amusing feature of Navions is that all the factory registration numbers were sequential, there's a easy formula to compute the serial number from the registration number (For those ending in K, subtract 3100. N5327K is NAV-4-2227B).

[Richard Warner]

When I built my first homebuilt, I didn't use the plans serial number, rather, it was
Serial Number W-1 Use anything you want.