Re: Open-source / community certification-like analysis of homebuilt air

Rob de Bie

Hi Brad,

It's a lot of work, and involves many disciplines
from the field of engineering. So it would be
best to do this with a team. Cross-checking and
discussion of the results would be other benefits.

The main point would be to have the results
public, so anyone can consult it, study the
calculations, and see whether his aircraft still is within the design envelope.

The specific example of the design speeds is a
difficult one. FAR-23 code (23.335) only has
minimum values, the manufacturer can select
higher ones. You also have to match them to the operational speeds.

But: I'm probably day-dreaming, since nothing like this seems to exist.


At 17:37 13 02 2017, you wrote:

Maybe I'm missing something but one does have
all the information. Or at least it seems that
way to me. You have all the information needed
to do design analysis (i.e. plans, actual built
planes to test with, relics to do destructive testing with, etc.)

Maybe I don't understand but one should be able
to derive the V-speeds appropriately.

-brad w.

On Mon, Feb 13, 2017 at 8:23 AM, Rob de Bie
[Q-LIST] <<mailto:Q-LIST@...>Q-LIST@...> wrote:
Hi Richard,
I've read many of the early Canard Pushers, a couple of hundred pages
so far, and indeed they make very interesting reading! When I wrote
my first posting, I was thinking specifically about the Q1 and Q2,
where the original company went bankrupt, and one of the designers is
deceased, so probably most of the documentation was lost. You might
need to reverse-engineer the design then.
Still, I think there's still a lot of information not available
publicly, that could be generated by a common effort. Just one
example: the design speeds used in the design: VA, VC and VD. If you
install a bigger engine, fly faster, you might exceed them. Yet I've
never seen them for any homebuilt design. Same for stresses, to what
stress levels is the design safe? What if you increase the mass,
which happens all the time. Knowing the design work would allow a
check of these questions.
At 20:50 11 02 2017, you wrote:
Hi Rob,
Most popular designs are well tested to destruction and improvements are
tested properly.
The Long eze is a good example, and if you read the Canard Pushers that
Burt published, he details all the testing that RAF and his associates
If you have not read the Canard Pushers it sounds like you would enjoy
it, as it tracks the development of most of his designs.
In this day and age of Catia modeling and multiple Stress simulations,
its great to see that manufacturers are still forced to waggle the wings
until that fall off to prove the guy with the calculator and pencil or
the latest fatigue simulator has not got it wrong again don't you think ?

Richard Thomson

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