What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Weight and Balance document after paint

Draker

Draker

Well Known Member
Looking forward to bringing my plane back from the ol' paint shop. Very exciting!

The paint is going to add ~15-30lbs depending on how elaborate it is. I would like to legally fly it back from painting. My current Weight and Balance document contains old data pre-paint. I will not be able to produce an updated, accurate document until I return and re-weigh the aircraft, and therefore will not have a correct W in AROW. What is the applicable FAR that I need to be studying to understand my options?

EDIT to clarify: the airplane is already airworthy, documented and flying for a year. Also, I am not concerned that the paint will put me anywhere in the envelope that is unsafe. It is a standard, by-the-plans RV. My question is about the legality of flying with old W&B numbers typed into the W document.
 
Last edited:
If they charged you any significant amount for the job I’d wonder why they don’t do a W&B. Maybe they don’t even know to balance the flight controls? I’d be more worried about that than paperwork.

See 91.407. I’d say that 15-30 pounds and a change in CG qualifies.

Things are usually a problem with the FAA after the fact. Assume you have an incident that you walk away from. Pretty sure they’ll get you for not having a current W&B after they ask about that sweet new paint job that’s all messed up, they’ll cite 91.3, and 91.13 for careless operation, and probably something else related to being the owner too.

If nothing happens then nothing happens. Ask yourself why there’s a W&B requirement in the first place? I’m sure there’s a shop on the field that can do a W&B
 
Right or wrong, I weighed mine after I flew it back home from the paint shop. My reasoning was that it was just a single person on board with no baggage and something less than full fuel. Using the W&B spreadsheet and estimating what the changes would be before I picked up the plane, there wasn't an appreciable difference. At least not enough to affect how it would handle on that single flight (like changing a prop). And there wasn't an easy way to weigh it at the paint shop. To the letter of the law, perhaps you should perform a W&B before you fly. But I would guess most people weigh their plane sometime after they've flown it home.

How many of us weigh every passenger, including water bottles, headsets, cameras, jackets, etc.? Or do most of us estimate weights? How far do you go to get a spot-on accurate W&B for every single flight? It's an interesting question...
 
Last edited:
I suspect a lot of folks do this. From a practical standpoint on something as small as an RV it's probably going to turn out okay. If you know that a paint job weighs somewhere around 30 lbs and it's going to move the cg aft a bit it wouldn't be that difficult to guesstimate what you have to do to make sure you're still in the CG envelope. I think from a physics standpoint it's probably more concerning that somebody might blast off with out of balance flight controls.

However, to be in compliance with applicable FARs, I believe you would need to get a ferry permit for this. I'm not speaking from personal experience here, so somebody please correct me if I'm wrong.
 
You cannot legally fly the bird until the Airworthiness certificate and Ops Specs have been issued.
These cannot be completed until a weight and balance has been calculated and included with the aircraft paperwork. An inspection by a DAR will certainly include W&B and fwd and aft scenarios.
 
Jpm757 said:
You cannot legally fly the bird until the Airworthiness certificate and Ops Specs have been issued.
These cannot be completed until a weight and balance has been calculated and included with the aircraft paperwork. An inspection by a DAR will certainly include W&B and fwd and aft scenarios.
Click to expand...

yes but a bunch of RV's get all that stuff done prior to going to a paint shop. I believe thats the crux of the Op's question.
 
Jpm757 said:
You cannot legally fly the bird until the Airworthiness certificate and Ops Specs have been issued.
These cannot be completed until a weight and balance has been calculated and included with the aircraft paperwork. An inspection by a DAR will certainly include W&B and fwd and aft scenarios.
Click to expand...
Yep, that’s all true and correct, yet has nothing to do with the topic being discussed. :rolleyes:
 
To me, this sort of falls into the same bucket as the Condition Inspection sign off that says “I have inspected this aircraft on [this date]……and found it in a condition for safe operation”. Really? You did the ENTIRE inspection in 24 hours? Sure…I do that when I’m working, but most don’t - so technically, that’s a lie….do you worry about it? Does the FAA? Don’t ask…..

I’d do your due diligence, compute some weight and balance scenarios to convince yourself that you’re still in the box, and have a set of scales ready when you get home to do a permanent change to your W&B documents.

And yes - please make sure that the control surface balance has been accounted for/taken care of!
 
My paint shop did a W&B after paint and before they would release it to me. I re-balanced the elevators myself during re-assembly before it was weighed. I gained 18 lbs, CG moved aft very slightly, RV6, 3 colors, JetGlo paint.
 
W&B is estimated and updated all the time, but within reason of math.

Example
Part A xxx lbs was removed from Station X
Part B xxx lbs was installed at Station X

Example
no significant change ie sanded 12x12 area on wing and touched up paint. Which would be noted in the maintenance description as “no significant change to W&B”. You removed and added roughly equivalent amounts of weight. Basically one for one. Yes lots of this happens over time and aircraft hit scales again for some reason or another and find the freshman 15.

Example
it’s a large enough change and shift which can not be reasonably estimated like the examples above.

Not sure how you do that with “Installed 15-30 pounds at Station the entire airplane”

This is what scales are for.

You should be making an entry into the airframe logs for this paint. Ie a description of the work performed. https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_43-9C_CHG_2.pdf

https://www.ecfr.gov/current/title-14/chapter-I/subchapter-C/part-43/section-43.9



Aircraft prepped with xxxx and painted with Jetglo “RV-Awesome Blue”. Flight controls removed, reinstalled and balanced. Aircraft weighed on xxx scales
Left wheel xxx at station xxx, Right wheel xxx at station xxx , tail wheel xxx at station xxx. New empty weight xxx, new moment xxx. New W&B computed and updated. All work performed in accordance with xxxx yyyy etc etc. Return to service etc etc…Signature/Date

There should be something that resembles an entry for the work performed and what it did to the aircraft. Everyone has their own style but needs to capture a description of the work performed.

In the course of making a proper maintenance entry a new W&B should be happening as a result of a proper description of work performed.
 
Looks like I'll be borrowing a set of scales to bring with me and a few jugs to empty fuel into, and doing the weighing at the paint shop, plus balancing the control surfaces. Sounds like the right way to go.
 
Draker said:
Looks like I'll be borrowing a set of scales to bring with me and a few jugs to empty fuel into, and doing the weighing at the paint shop, plus balancing the control surfaces. Sounds like the right way to go.
Click to expand...

If there’s fuel available at the paint location, why not just top off the tanks, weigh, calculate the empty weight?
 
This is what I would do. Calculate how much weight you can add to the spinner and still be within the weight and balance. Then calculate how much weight you can add to the tail and still be good to go. I would think that the numbers will show that it is virtually impossible for you to be out of W&B after paint. Save the document so just in case there is an issue you can show that you did you due diligence and W&B could not be an issue.
 
RV10Pilot said:
This is what I would do. Calculate how much weight you can add to the spinner and still be within the weight and balance. Then calculate how much weight you can add to the tail and still be good to go. I would think that the numbers will show that it is virtually impossible for you to be out of W&B after paint. Save the document so just in case there is an issue you can show that you did you due diligence and W&B could not be an issue.
Click to expand...

I don't argue practicality but, what does that Maintenace log entry look like?

"calculated all possible scenarios and updated many options for W&B."

Will it fall out of the sky, most likely not. Will you some how load this up solo and be out of CG and/or gross, most likely not.

I think that idea is equivalent to the carboard over the license tag on a car that says "applied for new tags". Good initiative but unfortunately falls short of correct.
 
Flight control 'flutter'
I was on an airliner thirty years ago and shortly after take off I looked out my window to see the left aileron fluttering out at the wingtip. I told the stewardess who dismissed me... Admittedly, I did not know anything about flight control balance at that time.

Years later about 65 hours after my private check ride and I found that I was giving a statement to the NTSB regarding a rental aircraft I had flown and the next flight broke apart during aerobatic maneuvers, both fatalities... Final report findings was that the elevator and rudder had been recently repainted and while one half of the elevator was destroyed beyond being able to weigh and check the balance, they found the surviving section had a very heavy training edge, outside of the design envelope.

Every paint shop should have someone (A&P or designated equivalent, ie builder) who has the specification, performs the check, and makes the logbook entry. Before any flight, need not be said.

What happens during flutter is like bending a paperclip back and forth until the metal fatigues and fails.

No, I could not feel or see any flutter during my one hour rental flight.
 
Scott Hersha said:
My paint shop did a W&B after paint and before they would release it to me. I re-balanced the elevators myself during re-assembly before it was weighed. I gained 18 lbs, CG moved aft very slightly, RV6, 3 colors, JetGlo paint.
Click to expand...
This was my experience, except I had a friend help me paint it. Gained 19 lbs and the CG moved slightly aft. Three colors of Axalta AF400 primer and paint.
 
What about adding a station?

If paint can shift the CG slightly, then it has an arm. Perhaps someone who has the numbers can calculate what that arm is by working backwards for a RV-7A since that is what you have.

Once you have the arm and the estimated paint weight, you can calculate the changed W&B until you re-weigh the plane.

Perhaps one of the more legally knowledgeable can answer if this would satisfy the W&B requirements to legally fly the plane home before physically weighing the plane.
 
You must log in or register to reply here.
Back
Top