One person has made these suggestions:

 

If an STC proves necessary, WHY? I would suggest working 

with AOPA and/or EAA to "make the (present) system work" 

because this is a "safety of flight" matter that simply restores 

relationships to the way the plane was officially approved as 

being in conformance with its type certificate when it left the factory.

The authority for the work, whether 337 or STC, would be a 

simple factual statement, attested to by the IA, that the aircraft 

has had modifications which, while proper and approved under 

applicable standard practices, have changed the angle of attach 

of the wing which adversely affects flight characteristics in the

transition from flight to ground operation and significantly reduces 

designed safety during operations in higher crosswinds. 

Both TC 718 (p. 2) and 787 (p. 5) state, under "SPECIFICATIONS 

PERTINENT TO ALL MODELS": 

Leveling means Hatch sill on either side of fuselage

>From this it is clear that any airframe NOT level by this criteria

 when static on the ground does NOT conform to its Type Certificate. 

A pilot is authorized (or his mechanic, in his stead) to make parts 

necessary to restore the original and proper relationship of the 

wing to the ground.

It is equally clear that "tail height" was never a constant reference 

due to variables relating to which nose wheel fork, and rubber taxi 

shock absorbers (meeting new specification thickness) or Belleville 

springs are fitted. 

It should be pointed out that the Univair fork supplied with their 5" 

nose wheel kit did NOT raise the nose because they used a shorter 

taxi spring. The Forney fork for the 5" nose wheel used in conjunction 

with Belleville springs on all M10, Alon and some Forneys may have 

resulted in a near-level condition out of the factory.

I'm not at all sure that the 415-E, G and F-1 aircraft with the single-

fork 5" nose wheel were level when they left the factory, but if the 

CAA representative accepted them that way it would simply be another 

example of an inadvertent omission. Similarly the necessary stainless 

firewall continuation (under the cowling from firewall to windscreen 
when the model 415 with ERCO engine was converted to the 415-C) 

was omitted in approval of the model 415-C.

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