Rob,

 

Man, you are really stretching my memory.  I think the original link used rivets to hold the rod end in the main gear over center link and severe side stress had caused a few failures.  I had an '89 kit with the bad part that I replaced with the newer one before I finished building in 1996..  I think the new part used heli-coils and a threaded rod end for a more secure marriage.he new part.  BTW, those side load failures occurred without loading up the airplane.  If I'm wrong I am sure some young whippersnapper will correct me.

 

Yes, the landing gear and its related parts were designed for the 1685 max lading weight and are still the same.  Think about the way the nose gear is attached to the engine mount - not the beefiest set up.

 

And, yep again - the 300 series Lancairs have had the most options, alterations and modifications you could  ever think of.  Engines from 320s to 360s to 390s.  Some with turbo charging. Prop models galore. Electronic ignitions of several varieties.  Fast or slow build kit.  Trim tabs or inside trim. Wing extensions.  Outback landing gear or regular.  Parallel or front hinged canopy.  Fuel tank additions and deletions of the header tank, selector valves or not.  Big tail or small.  Long engine mount or short standard.  And, many more of modifications in every combination.  Every Lancair 320/360 is a one off. 

 

Do what you want - you are building it.  But, remember that it is an experimental aircraft and no matter who designed it, it is your name that goes on the make/model id plate. 

 

Good luck,

 

Scott Krueger AKA Grayhawk

 

With all of this discussion on max gross weights for the Lancair 320/360,
what is the engineering/design decisions that has gone into increasing the
gross weight?  The reason I ask is that, I assume, the factory has done some
type of engineering analysis.  The factory increase in gross weight document
is:

http://www.lancair.com/media/builderupdates/235-320-360/Non-PDF-Docs/WeightI
ncrease320-360.pdf

Here, it states that the new main gear overcenter link must be used
(Standard in kits produced after 10/93), the stall speed will be increased,
and the allowable G limits are reduced to +4.0/-2.0. (Those reduced G limits
aren't normally a problem for me)  The maximum landing weight has not been
changed.

In Mac McClellan's blog
http://macsblog.com/2011/08/when-a-kit-aircraft-is-not-a-kit-aircraft/ he
asserts that all changes to a kit make each one a one-off.  He refers to
Dick (Van's) VanGrunsven's article about the engineering that goes into
setting the RV-10's gross weight:
http://macsblog.com/wp-content/uploads/2011/08/94-99_Handbook_v6.pdf

While Van (nor I) dispute that there are airplanes flying around
(successfully) with higher gross weights, I'm concerned that I do not have
the engineering background to justify any gross weight other than to use
what the factory provides.  Vans asserts that the built-in engineering
margin belongs to the designer and you can't have it.

In particular, does the G loading become so low that I'd have to be
concerned about turbulence breaking my wings off?  I have no idea.

Granted, the 360 has a lot of factory options.  And I agree that no two are
probably alike.  But I feel a little better while building mine that I'm
sticking to something that a real aeronautical engineer designed and
approved.  (That is meant that *I* do not have the aeronautical engineering
skills to make that determination, I can't speak for anyone else)

Thoughts?

I have no idea what mine will weigh when finished.  But I know the
girlfriend likes to pack heavy. Might be time to look for a 4-place...

-Rob  (Lancair 360 MKII, 15% completed)



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