All: I said:
> In August of 1948, Ercoupe Service Memorandum No. 51 was issued "...to > strongly recommend..." the installation of > 5.00 x 5 and 6.00 x 6 nose wheels on Ercoupes "...which are subject to > unusually rough landings or operating from unusually rough fields." > Because ERCO did not change the length of the nose strut taxi spring > when fitting these larger nose wheels, and no main gear spacers were > installed, it must be presumed that planes equipped with larger nose > wheels DID NOT emerge from the factory with level sills (weight and > balance sheet diagrams and service instructions notwithstanding). While correct with regard to the Erco single-fork support for the 5" nose wheel fitted to the 415-E, G and early Forney F-1s and the later Forney-Alon-M10 double-fork support (by far the majority of 5" wheel installations), there are two exceptions that should be mentioned. Per ESM 51, when the 6.00 x 6 wheel was installed, taxi spring 415-34041 (the "standard" one) was removed and taxi spring 415-34364 was substituted. I don't know what the length of this spring was, but it is no longer listed on the Univair price list. They do offer taxi spring 34352, but I have no information as to its length. This was intended for ski installations. Also, when the Univair "steel conversion" (see Parts Catalog, p. 21 & Fig. 16) substituted the Cleveland 5.00 x 5 wheel assembly for the 4" original, taxi spring U415-34104 was substituted. In each of these specific cases, it is likely that a level sill would result if the rubber donuts remain "in spec". While substituting the U415-34104 taxi spring for the standard 415-34041 on ALL 5" nose wheel installations would likely eliminate any need for MLG spacers, this spring is not "approved" for use other than as part of the U-415-34090-1A 5" nose wheel conversion assembly according to Univair. Sorry, WRB
