John
I wont speculate on the reasons for delay in certification as I am too aware of
the law of libel. However, my understanding of the main issue with increasing
the MTOW is demonstrating the landing gear is capable of withstanding the
additional
loads, potentially with prop clearance issues on the mono in addition.
RIchard
Sent from my iPhone
> On 15 May 2019, at 08:39, John Wighton <john@wighton.net> wrote:
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> Quote:
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> Here in Canada we can declare whatever gross weight we want (wisely or
> not). Seeing that the added weight is itself in the wing and results in no
> increased stresses, I figure I could simply increase the gross with long
> wings by the same 100lbs without penalty (assuming enough HP). No?
>
> It is true that inertia relief can be credited to mitigate loads and this
> gives
a proportional benefit with heavy wings. But to assume the stresses do not
change is incorrect. The MG wings generate more lift, hence the bending moments
and shear forces on the root will be higher.
>
> I believe the spar depth was changed to increase 2nd Mt of area. The goal
> therefore
may have been to match the standard a/c stresses. I have some of Jason
Russell's work on file from many years ago, it is probably worth taking a look
at that and any other design data (at LAA?) to see what the margins are.
>
> I suspect that the long delay in gaining approval for the MG version stems
> from
a reduction in structural margins. Perhaps someone can tell the story????
>
> --------
> John Wighton
> Europa XS trigear G-IPOD
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> Read this topic online here:
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> http://forums.matronics.com/viewtopic.php?p=489233#489233
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