VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.


Go Back   VAF Forums > Main > RV General Discussion/News
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 12-16-2020, 04:42 PM
Jvon811's Avatar
Jvon811 Jvon811 is offline
 
Join Date: Mar 2014
Location: KFNT Central Michigan
Posts: 214
Default W&B Question for the Lawyers or DAR's...

If you're short on time or patience... The short(er) version of the question is at the bottom.

What exactly constitutes a legal Weight and Balance on the RV? The included pictures are screen grabs of some data here so people don't have to go looking for my sources. This is a question my black and white, look it up in the book, Part 121 brain just wont let go of.

I know FAR 91.9 roughly spells out "ARROW" as the required documents onboard. What exactly is the W in a Experimental aircraft with a Special Airworthiness Certificate? FAR 91.103 states I need to know "all available information concerning the flight" which would significantly change the W&B with or without a passenger in my RV-4 for example. Section 14 of the Van's Construction Manual does have a nice W&B form with sections for Most Forward CG and Most Aft CG which does define the limits nicely for the CG envelope. I believe one could argue that if I'm standing on a ramp, with a passenger, and we both weigh less than the Section 14 W&B form has calculated, then we're within known W&B numbers and 91.103 compliant but not really armed with a W&B of the current state of my airplane with my passenger, fuel, baggage, and myself.

AC 20-27G refers to a "weight and balance report" being submitted with the paperwork for a new homebuilt, but I can't seem to find what exactly that report is. (far right attached pic)

FAA Order 8130.2H spells out W&B requirements for E-LSA, but not E-AB (that I could find) (far left attached pic)

Order 8130.2H also has a sample form of 8130-11 (irrelevant, I know) showing what is in a Weight and Balance Report. That's the only place I've found on the internet in a FAA document showing what's in a "report" (middle attached pic)

So if someone is a second hand owner (such as myself), or a builder just re-weigh's their aircraft after some additions or subtractions, what do they use? Some might use their own forms, but I'm wondering how many just go to the Van's Aircraft website and download what I refer to as the "Short Form". If you've seen it, you know it's a Empty CG W&B form, and that appears to be all it is. CG of your empty airplane only. No room for information about your airplane with fuel, pilot, passenger, or baggage. If you're like me, you might also have Foreflight on your iPhone (or equivalent) which is always in your pocket and you can whip up an actual/real time W&B anytime to supplement the short form.

So the real question is, is the downloadable Empty W&B short form on the Van's Aircraft website a legal W&B to carry in the airplane (with supplementation i.e. Foreflight on your phone). Or does it HAVE to be a copy of the 2 Page, W&B form from Section 14 outlining the full possible CG range? I understand there is a Note right at the top of the short form stating it's not a replacement for the Section 14 forms. How many though, if any, second-hand RV owners have the long forms if they've reweighed the airplane? If I were to be ramp checked, standing there with two people and my RV-4, would the downloadable Empty CG short form suffice?


Through all of my 2+ hours of research to type this question up, I think I've sufficiently answered my own question, but I'd like to know an ASI or DAR's opinion.
Attached Thumbnails
Click image for larger version

Name:	elsa wb.png
Views:	91
Size:	82.9 KB
ID:	5778  Click image for larger version

Name:	8130-2H.png
Views:	91
Size:	102.7 KB
ID:	5779  Click image for larger version

Name:	Screenshot 2020-12-16 183105.png
Views:	86
Size:	230.7 KB
ID:	5780  
__________________
-Justin

RV-4 N249P
O-320, Dual P-Mags, Warnke Prop, Short legs, Manual Flaps, GRT Sport EX

Last edited by Jvon811 : 12-16-2020 at 09:10 PM.
Reply With Quote
  #2  
Old 12-16-2020, 05:40 PM
Jpm757's Avatar
Jpm757 Jpm757 is offline
 
Join Date: May 2013
Location: Sherman, CT
Posts: 966
Default

I believe all that the FAA wants is for you or anyone else to be able to be to calculate weight and balance. It does not specify how to go about it, just rather have enough information available to do so. This would include empty weight and C.G., gross weight, & locations of necessary stations for pilot/pax, fuel baggage etc.. So, if you are ever ramp checked, can you provide a W&B calculation? If the answer is YES, then I think that will suffice.
I carry the Van's W&B paperwork, but also have electronic available in my EFIS.
__________________
Jake
RV6 #20477 completed 1991 sold.
RV7 #72018 N767T first flight 11/21/2017
(KOXC)Oxford, CT, (0NY0)North Creek, NY.
1941 J3 Cub skis, floats.
Building Javron Super Cub.
2020 dues gladly paid.

Last edited by Jpm757 : 12-16-2020 at 06:55 PM. Reason: Ad
Reply With Quote
  #3  
Old 12-16-2020, 07:47 PM
gyoung's Avatar
gyoung gyoung is offline
 
Join Date: Jan 2005
Location: Spring, TX
Posts: 292
Default

I'm prepping the paperwork for my inspection and what needs to be submitted for W&B consists of the weigh job worksheet to determine the empty weight and empty C.G., an equipment list showing everything installed when weighed and a series of trial calculations of loaded W&B at most forward and aft C.G. At a minimum you need to carry the weigh job worksheet in the aircraft and be prepared to defend your loaded condition when ramp checked. That weigh job worksheet is the only place I know of where the max gross weight is specified. The worksheet also shows the arms and C.G. limits that would normally be in a POH.

Some certified aircraft are not individually weighed and come from the factory with a calculated empty weight and empty C.G. accounting for the installed equipment options. All the arms and C.G. envelope are in the POH.
__________________
Greg

1950 Navion - flying
RV-6 - first flight 5/6/2021
1940 Rearwin Cloudster project next
4 L-2 projects on deck
Reply With Quote
  #4  
Old 12-16-2020, 07:51 PM
RV6_flyer's Avatar
RV6_flyer RV6_flyer is offline
 
Join Date: Jan 2005
Location: NC25
Posts: 3,692
Default

I have been retired from being a DAR for 7-years. Mel has done 100 times more airplanes that I have so he may add more info than what I remember.

You are required to have a weight and balance report in the airplane.

The FAA required that the report be within weight and balance limits for initial airworthiness inspection.

For the initial Airworthiness inspection, the report was required to include Empty Weight CG, Gross Weight CG, most Aft Weight CG, most Forward CG, and first flight Weight CG calculations. (show calculations) IF the report had at least that info, it would typically fly through the FAA paperwork inspection. IF most forward and most aft are at extreme balance locations, then the W&B report will tend to help the pilot have a "Go - No Go" indication.

Send me a PM with your email address and I will send you an OLD spreadsheet that I put together back before 2013 with conditional formatting that would highlight in GREEN for good and RED for bad CG balance.

The attached PDF is what the *.XLS looks like before it is filled out. You will be able to modify the spreadsheet to fit your needs. There are some hidden rows with additional cases that may be helpful but what I am showing you has typically be the minimum required. (It worked for me on numerous ramp checks when I was flying formation in air shows with my airplane.)

Click image for larger version

Name:	W&B_Sample_With_Conditional_Formatting.xls.pdf
Views:	110
Size:	42.5 KB
ID:	5791
__________________
Gary A. Sobek
NC25 RV-6
Flying
3,400+ hours
Where is N157GS
Building RV-8 S/N: 80012

To most people, the sky is the limit.
To those who love aviation, the sky is home.
Reply With Quote
  #5  
Old 12-17-2020, 08:39 AM
jnorris's Avatar
jnorris jnorris is offline
 
Join Date: Aug 2007
Location: Oshkosh
Posts: 239
Default

The weight and balance report my FAA office likes is one that includes all the info on the spreadsheet I've attached here. Read the notes carefully on the bottom of the form, as these outline the way the report should be filled out for certification purposes. (The forum won't accept an Excel file, so I had to turn it into a pdf. I can send the Excel spreadsheet to anyone who wants it. just let me know)

Once the aircraft has been issued an airworthiness certificate, the important info to have on board is that which will allow the operator to calculate a weight and balance for the flight being undertaken. So empty weight and CG, CG limits, arms for all the loading points. and gross weight info is the bare necessity.
Attached Thumbnails
Click image for larger version

Name:	Weight And Balance Form.pdf
Views:	116
Size:	184.3 KB
ID:	5809  
__________________
Cheers!

Joe
Reply With Quote
  #6  
Old 12-17-2020, 08:51 AM
edclee edclee is offline
 
Join Date: Aug 2008
Location: Lancaster, SC
Posts: 186
Default W&B

I am not totally sure what you are asking, since you raise MANY questions, but the crux of the matter is that yes, you must have weight and balance information in the aircraft based on what the AS_BUILT, CURRENT aircraft W&B is. Whether that is from your original weighing and corrected as equipment is added and removed or an as-is current actual weighing and balance. When the aircraft is originally certified by the FAA, the weight and balance can be anything you say it is, but be prepared to justify it, and later to prove that the aircraft is tested in the range of weight and balance in Phase 1 prior to going to phase 2.

Remember, you could have designed this aircraft yourself with no kit involved and no designer involved other than yourself. In which case there is NO W&B basis.

As for lawyers, that is another matter entirely. If it comes to that and you built a kit aircrat and decided on different W&B limits the lawyers would have a field day.
__________________
Sonex/Corvair 2016 Finished, Sold 2020
RV-9A 2005 Purchased
IO-320 160 hp
Exempt but happily paid for 2021
Reply With Quote
  #7  
Old 12-17-2020, 09:09 AM
Jvon811's Avatar
Jvon811 Jvon811 is offline
 
Join Date: Mar 2014
Location: KFNT Central Michigan
Posts: 214
Default

Quote:
Originally Posted by edclee View Post
I am not totally sure what you are asking, since you raise MANY questions
I guess that's my fault. I know what a W&B IS and what the book says needs to be on the aircraft. And I know what's required for airworthiness, I read a lot of AC 20-27G and 8130-3 last night. I thought my showing my sources would demonstrate that. My specific question is what constitutes a legal weight and balance for your actual flight.

Lets suppose all you have on board is the Empty CG "short form" for your aircraft, yet you get ramp checked with two 400lb pilots and 8,000lbs of baggage (obviously exaggerated). With regards to 91.103, do you think a Inspector would buy that you know your current W&B? My argument was that the blank forms in Section 14 of the Van's Construction Manuals that give outlines for the Most Forward and Most Aft CG ranges of your airplane (when computed out) draw a clear window. So, is the Empty CG only "short form" a legal W&B to carry in the airplane?

I was hoping an ASI or DAR could point to something specific in a document (that I haven't found) stating what needs to be carried other than a "weight and balance report". For all I know, it could be scribbles on a bar napkin. In a world where the FAA gets very specific about certain things, this one being so vague (even though they published an entire W&B handbook) is baffling to me.
__________________
-Justin

RV-4 N249P
O-320, Dual P-Mags, Warnke Prop, Short legs, Manual Flaps, GRT Sport EX

Last edited by Jvon811 : 12-17-2020 at 09:12 AM.
Reply With Quote
  #8  
Old 12-17-2020, 09:27 AM
Raymo's Avatar
Raymo Raymo is offline
 
Join Date: Nov 2014
Location: Richmond Hill, GA (KLHW)
Posts: 2,338
Default

Your operating limitations, which must be in the aircraft during operation, have the base-line W&B information, along with the following statement. It is up to the PIC to ensure the plane is within W&B limits, experimental or not.

21. The pilot in command must not perform any maneuvers that have not been flight tested or operate the aircraft outside the weight, airspeeds, and center of gravity limits tested.
__________________
Ray
RV-7A - Slider - N495KL - First flt 27 Jan 17
O-360-A4M w/ AFP FM-150 FI, Dual PMags, Vetterman Trombone Exh, SkyTech starter, BandC Alt (PP failed after 226 hrs)
Catto 3 blade NLE, FlightLines Interior, James cowl, plenum & intake, Anti-Splat -14 seat mod and nose gear support
All lines by TSFlightLines (aka Hoser)

Last edited by Raymo : 12-17-2020 at 10:01 AM.
Reply With Quote
  #9  
Old 12-17-2020, 09:40 AM
DanBaier's Avatar
DanBaier DanBaier is offline
 
Join Date: Mar 2009
Location: Rochester NY
Posts: 700
Default

I am not a DAR, but think what you're looking for is this:

First, to have the DAR inspection, you have to have weighed the aircraft and then put together sample loading illustrations to indicate that the empty and loaded aircraft CG falls within the fore and aft limits of the design. In the case of the 7, Van's (the last I knew) recommends a gross weight of 1800 - but if you indicate to your DAR that you want to go to 2000 and show the loading to that limit with the CGs within the fore and aft limits of the design, I wouldn't expect there would be a problem. After all, the aircraft has yet to be flight tested.

Second, having the airworthiness certificate, it's time to test the aircraft. In phase I, you incrementally ballast the aircraft to pump up the weight and to move the CG aft. In the course of testing, if the pitch stability starts to become static rather than dynamic, you stop. That data point becomes the aft CG. In the course of testing, if you move the weight up (in this example) to 2000 and you have the performance, that becomes your gross weight. You take this gross weight and CG info and put it into the entry that takes you from Phase I to Phase II.

So, let's say you want to be sure about your weight and balance - look at the current letter of operating limitations and you should find something like "...and the weight and CG location at which they were obtained...." These are the gross weight and the aft CG. If they aren't correct or need to be changed, I think your task is to put the aircraft back into Phase I, do the testing, and make the corrected entry to return to Phase II.

I think this is the explanation for encountering RV aircraft with higher gross weights than the Van's recommendations.

I am not saying it's a good idea to ignore Van's advice on the weight or, for that matter, the CG - their advice is based on the design of the aircraft not what someone can squeeze out of a climb rate. For example, someone puts an O-720 8 cylinder 400 hp lycoming on an unmodified airframe, loads ballast so the aircraft weighs 3000 pounds and manages to get 500 fpm climb out of it. They conclude the gross weight can be 3000 pounds. Safe? Legal? Smart? (We'll skip over the problem with the forward CG.)

As for the ramp checks, the last I knew you don't need to carry logbooks or test results with you. You don't have to keep them at your home airport. Presumably they're on a shelf in your garage at home. Your responsibility is to have considered the weight and balance prior to the flight. I don't believe you're even required to have that with you - just that it was done and you can speak to the result. So, if pressed in the ramp check, you simply agree to provide the worksheet to the inspector within a reasonable period. If pressed as to the gross weight number (say you used 2000 instead of 1800), you show them the logbook entry that documents the change from Phase I to Phase II. If you have an inspector doing the ramp checks who is unfamiliar with experimental aircraft, all bets are off (it could be a slog, but it will eventually get straightened out).

My $.02 - good luck.

Dan
__________________
RV7A (N7101) - Flying 10/2008
CFI- SE/ME/Inst
A&P
KC2ZEL
Reply With Quote
  #10  
Old 12-17-2020, 10:14 AM
JDeanda JDeanda is offline
 
Join Date: Apr 2013
Location: Ventura, CA
Posts: 244
Default Just My Experience

I reweigh our RV-6 or just calculate a Wt. & Bal. update every time we change something significant. The updated report goes into the aircraft file. Then I make up a Wt. & Bal. info sheet for the airplane. The sheet in the airplane is one page, and includes what you'd expect.... date, tail number, serial number, empty weight, empty weight CG, component locations, limits (all four.... oil, fuel, crew, baggage) with a sample Wt. & Bal. calculation and a simple form to fill out and calculate if the pilot wants to figure an actual weight and CG. The date and my signature go on the bottom. We got ramp checked once, intercepted as we shut down in front of our hangar. The FAA guy was professional, direct and efficient. My wife was flying that day so he wanted to see her license and medical. He looked at them in her hand, refusing to take them from her for examination. Then asked where the airworthiness, registration and Wt. & Bal. data was. She started to pull them out of the pocket on the side of the baggage compartment and the man quickly insisted she not remove them, he just wanted to see that they were there. That was it. Then we had a nice chat about the FAA issue hybrid car he'd driven there in. Here's hoping all ramp checks are like that one, it was no big deal. I was not worried, I look after the airplane and I knew everything was in place and legal. PM me if you'd like to see what our docs look like.

Last edited by JDeanda : 12-17-2020 at 03:36 PM.
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 03:47 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.