When Waldo Waterman had successfully flown W-4, he went on to build six W-5 Arrowbiles and called them #1 through #6, which did not correspond with their c/ns. Waterman tells in his memoirs that #1, #2, and #3 were completed in 1937 and flown to Cleveland for an appearance during the races. On the way, #1 was damaged in a forced landing in Arizona and was transported back to the Santa Monica, but the others made it.

The 1938 register says:

    [X262Y] Waterman W-5; c/n #2; Waterman Studebaker 100hp.
    [NR18931] Waterman W-5A; c/n #3; Waterman Studebaker 100hp.
    [NR18932] Waterman W-5A; c/n #4; Waterman Studebaker 100hp.

These must be #1, #2 and #3.

Paul Matt featured Arrowbile in Historical Aviation Album Volume 1, which is very good except for one thing—the caption under a picture of [NR18932] says: "NR18932 ... being flown cross-country with its sister NR16332 ... at the 1937 National Air Races at Cleveland." Yet in Weekly List of 4/8/36, Taylor J-2 Cub [16332] c/n 569 sits firmly in the middle of a long row of J-2s. Even if that J-2 had crashed the day after delivery, the registration couldn't possibly have been reused.

Arrowbile #4 was modified, probably on Waldo's "assembly line," to a non-roadable version with the wing from #1, and retaining the Studebaker engine. Called #4/1, it was probably [262Y].

In July 1938, Waterman was hospitalized with a ruptured appendix, and it took him a year to fully recover. In 1940, he bought back #4/1 from Studebaker, who owned it. Register of 2/15/41, has:

    [X262Y] Waterman W-6 (!); Waterman Studebaker 81G 100hp. No c/n.

In 1941, he installed an air-cooled 120hp Franklin in #4/1 and, in 1943, fitted slotted flaps. Later he revised the #5 wings into a one-piece cantilever wing and fitted that to old faithful #4. The #5 fuselage became a test rig to try out a tail rotor system for a Convair helicopter. The parts for #6 were re-worked after the war to become Aerobile [N54P] with a water-cooled Tucker-Franklin engine.

Jack Meaden wrote an article about Waterman in Air-Britain Archive 3/1998 listing all Arrowbiles made:

    #1 [X/NR262Y] - To Consolidated. Scrapped?
    #2 [NR16332] - To Consolidated. Bulldozed.
    #3 [NR18932] - To Consolidated. Bulldozed.
    #4 [NR18933] - Rebuilt non-roadable.
    #5 [NR18934] - Not completed.
    #6 [N54P] - Aerobile. NASM loan to San Diego Museum.

This list might be correct, except that he swallowed Matt's error with [NR16332], which should be [NR18931]. If so, [NR18933] and [NR18934] were reserved for Arrowbiles, but not used. In my register both of these numbers are used by post-war planes.

And Waterman's breezy Chevy Bird from 1968 was, indeed, [N262Y]—a nostalgic request to reuse the number, I suppose.

It's as "simple" as that... (— Lennart Johnsson 01/11/00)