With an hour of flight testing left to complete my 40 hr flight test phase, I am curious about exactly when/how I declare the operating gross weight of the aircraft.  In my operating limits, I simply have to state a couple of V speeds and at what weight I accomplished/acquired the values.  Is that all there is?

No POH is required, yet I find that there is no real clear guidance on where/how to unequivocally state the max gross weight of the aircraft.  For example, I flight test to the design limit of 1440 lbs, yet want to declare the max gross operating weight of 1320...how is that done., logbook entry? Anyone have some thoughts, I would appreciate!  Will also try calling the EAA guys tomorrow.

Thanks!  Dave

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I believe weight, CG and a few other items are required Airframe Log Book entries. Don't have a source for this right now, though.

And congratulations! It's a great feeling to finally get there.

When I entered my end of phase 1 testing I noted the gross weight there along with V speeds tested to.

Gosh, that was nearly 6 years ago for me, but didn't you have to submit the max gross weight stated on a weight and balance when you got the plane inspected for certification?  From "The Complete Guide to Aircraft Certification" (not an official FAA website, but authored by a DAR):

- Examine records that the aircraft has been weighed in accordance with established weight and balance procedures to determine the aircraft’s empty, gross, and most forward and aft CG location, including the weight and balance for the initial flight tests in order to help reduce stall, spin, and other control-related accidents.

The OL's usually don't require specifying the max gross weight, just the weight at which the required v-speeds were obtained.

And for those who may not know - if you ever intend to fly under Light Sport rules, never set the max gross weight higher than 1320 lbs at the time of certification because you can never go back later and lower the max gross weight to 1320 and legally fly Light Sport.

John

N750A

John, thanks for the link, but unfortunatley still doesn't clarify things in my mind.  The DAR did indeed run through my calculations and methodology and check my weight and balance sheets.  I presented a W&B sheet for my initial test flight based on the basic aircraft operating weight (myself as essential crew-member) and full fuel tanks.  Total gross weight of approx 1200 lbs.  This was the W&B for my initial flight tests.  I also had a W&B sheet demonstrating allowable/acceptable CG limits for the aircraft loaded in various configurations up to the design limit of 1440 lbs. and down to unusable fuel level weight.  I flight tested up to the max design limit, but now, as you pointed out - what if I want to explicitly set a max gross weight limit of 1320 for LSA purposes?  Seems like now is the time prior to completion of Phase I testing, and there should be some FAA way to document that.  I just assumed that would be a simple logbook entry upon completing Phase I.  Anyhow, makes for interesting discussion, but am / will fire off an email to the DAR who did the certification inspection to see her view of this.     Dave

When the weight and balance is submitted to the DAR, I "think" the gross weight has to be stated since it is a limitation of the aircraft as far as weight and balance.  I'm pretty sure somewhere in that blizzard of paperwork for certification that the max gross weight was submitted.  If it was a simple logbook entry after Phase I, seems like the OL would specify it - my OL doesn't and I have no later logbook entry of gross weight.

Now I'm totally in the boat, er, plane, with you, David!  This issue is clear as mud!

What did EAA say?  They are usually pretty savvy on questions like this.

John

OK, here is what I got from the EAA tech counselor...still waiting to hear from my DAR!

Create the W&B form for 1320 lb gross weight and keep that with the aircraft.  Get rid of the W&B sheets I created for 1440 lbs and my initial test flight gross weight.  Make the appropriate logbook entry with gross weight and V speeds for 1320 lbs when complete Phase I.  Fly confidently, knowing that the plane has been tested to 1440 design limit.

Easy enough to do!  Now I just got to decide if I want to limit to 1320 lbs or not!!

The advice sounds reasonable - you're creating a "paper trail" to establish the gross at 1320.  However, as I understand it, the original W&B and all your other paperwork remains on file with the FAA.  It seems your DAR should have required you state your max gross wt. on the W&B, although I will be the first to admit I don't think there's a FAR requiring that.  However, it would have firmly documented the max gross wt. in the original paperwork!

I saw a comment by Mel Asberry (the "Ask the DAR" guy) that apparently when a question like this comes up, the FAA puts the onus on the builder to demonstrate what the parameter (such as max gross wt) really is.  Likely, if you carry in your current W&B what the max gross is (1320), you'll be fine!

One small quibble I have with the EAA's advice on the logbook entry is that of course the v-speeds don't necessarily have to be at 1320/max gross wt.  Most OL's just say to "state the weight at which the v-speeds were obtained."  But, I guess in this case, it would be wise to determine them at 1320 as that would yet again work that number into your paperwork should a question arise.

I had no idea this was such a murky area!  On the bright side, questions like these probably keep several bureaucrats at the FAA busy, answering bewildered builder's queries, thus keeping unemployment down!  ;>)

If you're undecided about the wt limit, I would go with 1320 as you can always raise it later, but you can never go back to 1320 for Light Sport purposes.  On the other hand, if you can get a 3rd Class or BasicMed medical, Light Sport rules are not so important.

John

Update:

I asked the DAR who did my AW certification nearly 6 years ago about where the max gross wt is actually documented and he replied:

Hi John,

The FAA changes the certification order 8130.2(g-h-j) from time to time. They added new requirements the last revision that requires the new certification paperwork for new original certification to show max take off weight in addition to the most fwd and most aft loading configuration, CG range, datum, and level point..  This weight and balance document goes to the MIDO or FSDO for local record keeping but not to the records bin in Oklahoma City.  Aircraft that were certified earlier like yours do not need to have a new weight and balance.  That would only be required if you got an amended certificate for some reason.  This is because the new certificate must be made with the new regulations (updated requirements).  Hope this helps.

thanks for the note.  Love to hear from you guys.

Gary

So, there you have the reason for the confusion: the FAA changed the regs!  The last revision, FAA 8130.2j, was effective 9/21/2017 - that date or later you have to state the max take off weight on the W&B submitted at the time of AW certification.

John

I guess I'm good to go...my cert was issued 31 Aug 2017!!

Thanks for digging into things for us all John!

Cheers!  Dave

This also seems to allow for some "wiggle room" if ever ramp checked by the FAA. There appear to be no requirement to have documentation with a stated max allowable gross weight for our EAB aircraft certified prior to Sep 2017!  A POH, where a multitude of operating limits are typically found) is not required. The Phase I sign off with speeds at a certain gross weight and CG could be any set of values between min crew and fuel, up to any gross weight or design limit.  Having a current W&B sheet is the only place where the FAA could determine if you were in compliance with weight or loading limits.  Soooo....could one fly at 1440 lbs, and  a year or two or three later, (when tired of taking FAA mandated physicals), simply fly at the 1320 LSA limit and carry appropriate W&B documentation.  Someone shoot holes in my logic target...

[...On the bright side, questions like these probably keep several bureaucrats at the FAA busy, answering bewildered builder's queries, thus keeping unemployment down!]

Unfortunately, the several bureaucrats likely provide several differing answers.

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