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-   -   Weight and balance limits adjusted for RV-6/6A/7A/9A (https://vansairforce.net/community/showthread.php?t=182661)

greghughespdx 05-19-2020 06:36 PM

Weight and balance limits adjusted for RV-6/6A/7A/9A
 
We've published a handful of updates related to weight limits on the RV-6/6A/7A/9A aircraft.

Change to Max Recommended Gross Weight for RV-6 (taildragger only)

The first published change is to RV-6/6A Manual Section 14 (Weight & Balance). The change raises the recommended max gross weight for the RV-6 to 1650 pounds (this is a 50-pound increase and is now the same max gross weight as the RV-6A). Previously the RV-6 recommended max gross weight had been published at 1600 pounds. The RV-6/6A aerobatic limit (1375 pounds) does not change.

Why were these numbers different in the first place? When the RV-6A was created (after the RV-6 was already available), the structure was tested to a higher value to accommodate the slightly-heavier airplane. Structurally the two models are essentially the same from a max gross weight perspective. We are issuing this change to reflect that fact. And yes, we do realize it's been 35 years. :)

Removal of Nose Wheel Weight Limit on RV-6A/7A/9A with U-00019 Type Nose Gear

In addition, the max nosewheel weight for the RV-6A/7A/9A has been removed for aircraft where the new-style U-00019 nose gear leg (released in 2019) and engine mount are installed. In that case, the weight limits are instead determined using the aircraft’s overall weight and balance envelope. The new design was specifically tested prior to release around a worst-case forward CG loading scenario, and it was determined no limit is necessary other than the standard W&B envelope boundaries. We stated this year with the release but did not update Section 14 of the plans for each airplane, so we are formalizing that now.

The relevant documents are linked below:

DeeCee 57 05-20-2020 12:05 AM

Thumbs up Vans, thanks :cool:

Snowflake 05-20-2020 08:46 AM

Good to know! Now to figure out how to get Transport Canada to allow the increase...

Jpm757 05-20-2020 02:14 PM

For aircraft certified at #1600, I would imagine that one would need to re-enter phase 1 testing for some period of time to get the FAA to sign off on the gross weight increase. If Van's made this gross weight increase a "Service Bulletin" could that possibly allow for the increase with out having to jump through the paperwork hoops?

N941WR 05-20-2020 02:29 PM

When are you going to raise the GW for the -9 to 1800 lbs and bless the parallel valve (I)O-360 in it, as long as the existing V speeds are observed?

You had to know someone was going to ask that question.

greghughespdx 05-20-2020 04:22 PM

Quote:

Originally Posted by Jpm757 (Post 1432059)
For aircraft certified at #1600, I would imagine that one would need to re-enter phase 1 testing for some period of time to get the FAA to sign off on the gross weight increase. If Van's made this gross weight increase a "Service Bulletin" could that possibly allow for the increase with out having to jump through the paperwork hoops?

No, a SB wouldn't change the requirements. Gross weight change is considered a major change, so what is required for your airplane to make it legal will depend on your airplane's specific Op Limits. Joe Norris wrote a good article on this a while back. Questions (and directions) are probably something to deal with your local DAR or FSDO on. Im my experience, some handle these sorts of changes differently than others (unfortunately). But your op limits should spell out what's required for a major change.

greghughespdx 05-20-2020 04:51 PM

Quote:

Originally Posted by N941WR (Post 1432067)
When are you going to raise the GW for the -9 to 1800 lbs ... You had to know someone was going to ask that question.

Hah, of course. :)

The RV-9/9A gross weight won't change. That is a function of the wing structural design. remember that the RV-9 is designed to operate in the +4.4G utility category, where the 6/7/8 are designed to the +6G aerobatic category. The high-lift wing on the RV-9 is a great wing for a specific purpose (high-efficiency and performance at altitude), but it simply doesn't have the same loading capacity as the aero models, and gust loading factors on the -9 wing airfoil are quite different than on the others, as well.

Quote:

Originally Posted by N941WR (Post 1432067)
... and bless the parallel valve (I)O-360 in it, as long as the existing V speeds are observed?

We have not finished that analysis yet.

airguy 05-21-2020 11:01 AM

Quote:

Originally Posted by greghughespdx (Post 1432103)


We have not finished that analysis yet.

Really? [blinks back tears, sniffs twice] The church might actually take me back? They still love me? :):)

JonJay 05-21-2020 12:07 PM

My 6 will no longer be considered “grossed up” as I set the 1650# limit in the OP’s before she flew thirteen years ago. Me, wifey, 26g fuel, 100# baggage = 1650#.
Yay! (Although I was never worried about it.)
Thx Greg.

elev666 05-21-2020 04:25 PM

Why thank you Greg, that Ups my useful load by close to 10%! But as Rob Says i'll likely have to give Transport my last born ,,, wait a minute she?s not done school yet , I?ll call them tomorrow, ;)


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