RV-6 Gross Weight Question

Hello everyone,

I am wondering about what Max Gross weight other Canadian RV-6 owners show on their Special C of A.

You can have a 6 with 160 HP and one with 180 HP.
Correct me if I am wrong, but those 2 engines are 50 + lbs difference in weight.

From reading forums, there are 6's that go from 1600 lbs to 1800 + lbs MGW.

Please state your MGW and Engine configuration.

Thanks for your input.

Happy Easter
Harold

Gross Weight

Mine is registered in Canada at 1800#. O-320 fixed pitch wooden prop.
As long as your numbers for w&b work out there is no problem getting 1800#, at least that is how it worked for me bringing one in from the USA that already showed 1800# on the data plate.

For anyone else looking to import, you should know that the policy is now that the aircraft has to be registered at the kit manufacturer's numbers at time of import... In the case of an RV-6, 1600lb.

For an increase later, what is needed is some kind of documentation that supports that a higher weight is acceptable, and a climb test at the new gross weight to show that you meet minimum requirements at the new gross weight. You do the climb test after you get the rest of the paperwork squared away.

Transport Canada reply....

This is what I received from Transport Canada today:
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The process for application for Gross Weight Increase is as follows:

1. Make full and complete application which will include: Application for flight permit (TC form 24-0044) for purpose of conducting climb test, Fee payment for flight permit, provide TC with adequate substantiating documentation to justify a gross weight increase.

2. When Flight permit is issued, fly successful climb test and provide TC with satisfactory and complete Amateur Built Climb Test Report (TC form 24-0091).

3. Make application for issuance of new Flight Authority (TC form 24-0043) and pay fee for new flight authority.

4. Aircraft inspection by TC.

5. Relinquish superseded flight authority to TC.

All forms are easily accessible by simple Google search of the Transport Canada web page. I have included a link to all appropriate forms here: http://www.tc.gc.ca/eng/civilaviation/standards/maintenance-regsdocs-form-2943.htm

Fees also are readily available on-line in the CARS at CAR104 schedule VI and are as follows:
Issuance of a specific purpose flight permit, $45.
Approval of an amendment to the operations specifications set out in the flight authority?amateur built, $35.
You may pay these fees in person at the Ottawa TCC or by telephone at 1-800-305-2059.
NOTE: Inspector will require proof of fee payment for each application to be processed.

As far as substantiating documentation is concerned, we don?t have any conclusive list of expected items as all Amateur built aircraft are unique by their build standard. Citing that a similar aircraft on the registry have similar max gross weights is not acceptable as your build circumstances will not necessarily be consistent with those of the other similar aircraft. (i.e., the other aircraft may have heavier wing struts installed, etc.) It?s not like with Type Certified aircraft, where every aircraft of that type was built and is maintained to a consistent build standard.

With that, I would expect an applicant to provide loading calculations, weight and balance calculations that show aircraft in it?s current state (in any configuration) falls within the kit manufactures specified flight envelope.

Additionally, any modifications made to the structure of the aircraft in order to prepare the airframe to accommodate the extra weight and to what standard those mods were completed, with supporting documentation. Often, the kit manufacturer also has documentation specifying alternate max gross weights or other similar models/model upgrades that can be incorporated into the design and build of your aircraft to help substantiate your request.
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Does anyone have any document from Vans that would qualify as "substantiating documentation" ?
Harold

Hi,

I haven't tried, but I suspect without engineering documents it will be tough.

If I were to try I'd likely do some math tricks to get me through. Good news is that the rv-6 is good to +6Gs according to my quick google search.

Depending on how greedy I was on that day, I'd consider only asking for 10% a nice round number well within engineering tolerances, and the magic number in
AC 23- 24T for a number of things.

I'd reduce the max/min g-load in the POH at gross, by the same factor as I need a weight increase. (Not lower than 3.8) That should solve wing strength. Keep whatever baggage compartment limits the same.

Next problem would be the gear. Easiest fix for that is a reduced max landing weight. Keep the extra weight in the fuselage if possible, and hopefully the landing limit is reasonably above your empty weight plus the seats full of standard people.

Next comes revised stall speed(and other performance) I'd either offer to flight test it or do the math or ignore it and see what comes back from TC.

Then I'd write it up as official looking as I could and send it in. The times I've dealt with them they've been reasonable once the dialog is started... The hardest part is figuring out what boxes have to be ticked to get what you want.

Really hardcore option..... AC 23- 24T has the part 23 guidance for weight increases, showing compliance with all of the paragraphs should do the trick ;-)

Good Luck, and let us know how it turns out if you proceed.


Regards,

Derek

Rv-10 Empennage ordered
Glasair driver

People have said they are a bit more sticky now than in the past. Mine was approved 10 years ago at 1750 after submitting the climb test report. They didn't require anything more back then. You'd want to be well aware of the lower G limits and gear structure limits when operating at these weights.

H-Ottawa said:

As far as substantiating documentation is concerned, we don’t have any conclusive list of expected items as all Amateur built aircraft are unique by their build standard.

Click to expand...

This is only partially true, and a double-edged blade at that. An RV-6 is a "known" design, on the list of pre-approved kits. That's because inspectors will know what a "standard" RV-6 involves. If you claim that your aircraft is "unique" and qualified for something different than the "standard" RV-6, then your aircraft doesn't really fall into the same class as a standard RV-6... So it needs to be considered as a one-off design, and have a 51% determination done, to confirm that it qualifies for amateur-built status. Your inspector may also want to confirm that every part of your aircraft meets standard aviation practices, although they would probably overlook that if you said that the "base kit was an RV-6, but these parts are different" and pointed them out. If none are different, you're back to being a stock RV-6... So why should gross weight be different?

Does anyone have any document from Vans that would qualify as "substantiating documentation"?

Click to expand...

It's been said many times here and elsewhere that Van's used to issue letters on request authorizing gross weight increases on the RV-4 and RV-6. Despite repeated requests here and elsewhere, nobody has been able to show me a copy of one.

Personally, i'd just like to see what the letter says. I don't want to use one to try and increase my gross weight, I just want to see the wording. Specifically, does it authorize Normal category operations to the increased weight vs. Utility, for example?

FLY6 said:

Mine is registered in Canada at 1800#. O-320 fixed pitch wooden prop.
As long as your numbers for w&b work out there is no problem getting 1800#, at least that is how it worked for me bringing one in from the USA that already showed 1800# on the data plate.

Click to expand...

Same for me when I brought my 6A in in 2011. I submitted all the forms to MDRA using the 1800 lb gross that the plane was registered with by its builder in the US, and, much to my MDRA inspector's surprise, they didn't correct that number during the import process, so he didn't either. The 6A still meets the wing loading limits at that weight, maintains standard category g loading limits as well, and certainly had no difficulty with the climb test (which has to be done during the import process no matter what gross you're asking for). Very glad I used those numbers on my application; as others have said, MDRA's official position is that they will only approve the kit maker's recommended gross weight, and leave it between you and Transport Canada to discuss any changes at a later date, but even now it doesn't always happen that way. In other words, if you're importing you might as well put the 1800 lb figure on the application; the worst that can happened is they say no, but it might just go through that way and save a lot of paperwork later on.