LSA - Aircraft Mods allowed?

[LenM]

Hoping some of the more informed on the forum might be able to assist me...

I would like to add exstra storage to my little aerie and am considering either a belly pod or wing pods. I've done some prelim designs and will still do all of the require due dilligence etc etc.
Accordingly the design part I'm fairly comfortable with, the part that I'm not is the legal requirements?

Am I allowed to add a storage pod to my plane?

In the event of any incidents, will this now default my insurance? Or similarly, will I have problems with the aviation authorities?

[KFA]

Hi Len,
It would be best to contact engineering dept at CAA but I can tell you now that the type of attachements you are talking about will require drawings, engineering analysys and most probably some sort of a static test to put their minds at rest that your torpudo will not dislodge in flight and kill someone or that the plane might suffer structural damage because of the weight acting on the stress points on the fuse that it was not designed for. I must also add that I would think 3 times before adding anything to the liftstruts. From the pic I can just imagine the additional forces that will be created by the drag and the weight of the attachment to the struts. The Belly pod is a better plan and might be worth investigating.

[LenM]

KFA

Thank you very much for your inputs, much appreciated!
I assume this would not be the case if it is 'approved' by the orginal aircraft manufacturer, or if I wish to purchase it from a certified supplier?
OR is the aviation legislation between countries so different that a US pod would not neccessarily be allowed in SA?

I really do appreciate your inputs, thanks!


PS: So STRICTLY speaking I am not allowed to mount wheelspats on my aerie if the original aircraft did not have it as part of the design...

[RV4ker (RIP)]

How does one do R&D?

[KFA]

To answer Len, if the original manufacturer had it approved then there it will not be an issue. If you are rowing in unchartered waters then you will have to supply data to CAA to substantiate the mod.

George, the R&D is not a problem it is the substanting data that accompanies a change that some people might find a huge challange and not worth the effort. I also do not agree with all of the law but from CAA's point you can not let every Tom Dick and Harry make changes to an aircraft that could affect it's structure without a system in place. For instance, What would the capacity of the pod be. Lets say the volume is 100 liters and 30kg then @ 4g plus 150% for LSA certification that will be a 180kg extra load below the seat. Now if you did not test or calculate this how do you know if the seat is still going to be below you when you do a 4g manauvre

[RV4ker (RIP)]

100%. But kinda defeats he object of Experimental.....

[KFA]

Agree 100% but Amateur built and Experimental are 2 different things. Amateur build means useally the 51% rule where you have bought a kit for assembly and Eperimental is just that, You are ten to one the deisgner and builder of your own plane, this gives you the freedom to experiment.

[RV4ker (RIP)]

Yip, but that USA. Local there seems to be no experimental "category"....

I know plenty guys who in "old" days added fuel tanks for eg without any issue, replaced props, engines etc. Seems those days are gone

[LenM]

Thanks for these valuable inputs!

I obviously don't know what the law states on this matter, but it makes perfect sense to have airplane mods regulated...
Everytime a modification is made without a due process and analysis it could end in an 'incident', which in turn is bad for all of us in GA!

From my perspective I can't imagine it would be worthwhile to persue the full due diligence process required to have such a mod certified. Will see whether I can get anything from the original designers...