Whose responsibility is accuracy of W&B?

Yes, but:
If it is a Cub, you really don't have to worry about unbalancing controls. What you are worrying about is losing 100 lbs of useful load. If that is ok, then by all means weigh it.

But then, I would think that, having done that, you would be reluctant to load above the legal max, for the same reason that drove you to weigh it. You want to be 100% legal.

Don’t 135 and 121 regs require airplanes to weighed every 36 months? That’s not far off of what I’ve done with my planes.

Bob talks a good story about falsifying your actual weight but here’s the truth. My planes fly just as bad at gross with a bogus W&B as 100# over gross with an accurate W&B. The difference is that I know where the performance threshold is. Old AK pilots advise every new pilot that the first thing you do after an accident in a heavy plane is to drain the fuel before the feds get there. If the situation is egregious enough? Toss a match. I prefer to have equipment worthy of the task.

All very helpful.

Here is a follow-up.

You own plane w what you think is accurate w&b. Load up. Have some sort of accident. Does FAA look at paperwork or weigh your plane? If paperwork was off and EW was 100+ pounds low and that put you over gross- does that paperwork that reduce potential liability to you as pic/owner?

If liability is still there shouldn't everyone weigh a plane prior to purchase?

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dgapilot said:

I think the concept of S-LSA is the worst thing to happen to general aviation!

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This is good to know as someone who was considering one.

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Can’t you convert it to E-LSA? All the benefits of Exp but with a gross weight limit.

dgapilot said:

There is no empty weight limitation for a Light Sport aircraft (unless specifically identified by the manufacturer). The only limitation is gross weight. Of course, when the empty weight goes up, the useful load goes down. That's what often makes a single place airplane out of a two place airplane.

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I thought all s-lsa had to have a minimum of 430 lbs useful load? This would mean an 890 limit or they must go e-lsa I believe.


https://bydanjohnson.com/pilotreport/the-s-lsa-useful-load-requirement/



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Hardtailjohn said:

When I worked in a paint shop we always weighed after as well as balanced surfaces as applicable. I'd definitely expect it if I had an aircraft painted.
John

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So you balanced the control surfaces and reweighed the entire airplane after repaint? Would be curious how different they would be between the two paint jobs.

Cardiff Kook said:

I thought all s-lsa had to have a minimum of 430 lbs useful load? This would mean an 890 limit or they must go e-lsa I believe.


https://bydanjohnson.com/pilotreport/the-s-lsa-useful-load-requirement/



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That requirement does not show in the definition of Light Sport in 14 CFR 1.1. It may be in the ASTM standard, but not in the regulation.


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Steve Pierce said:

So you balanced the control surfaces and reweighed the entire airplane after repaint? Would be curious how different they would be between the two paint jobs.

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The shop I ran also balanced controls and reweighed following paint.


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I bought an original 90hp Super Cub with 800X4 tires and 1 wing tank a couple months ago. Its never been reweighed. Was recovered once in the 90s. When I get caught up with my other projects I'll weigh it and see how far its off.

dgapilot said:

That requirement does not show in the definition of Light Sport in 14 CFR 1.1. It may be in the ASTM standard, but not in the regulation.


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Okay. So I wonder if it applies? Or if it's old not really true.

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I think I was misinterpreted. I am not advocating illegal loading.
A Super Cub with a 400 lb useful load is really a one-place aircraft. Sure, you can put two 200 lb guys in there and 36 gals of fuel and it will perform just like a good Cub should - but draining fuel after an "event" won't work.
Worse - maybe there is a clause in your insurance policy about deliberately flying in an unairworthy condition.

If - if you are going to load up, it is far better, in my opinion, to have legal paperwork that shows you in limits. And as far as I can tell, taking the factory weight and adding mods mathematically is still legal.

I suppose you can weigh it for your own comfort, but if you do the paperwork associated with that weigh-in and make the useful load 400# you might have trouble selling. Ask Cardiff about his major reason for rejecting potential purchases.

Steve, it varied. Some were a LOT different from what was claimed, and I think that was from additions and subtractions of installations in the past as well as (if not more so than) paint differences. Some older paint jobs, when the really heavy automotive stuff was used, benefited a fair amount by the use of polyurethanes and some came in that had so little paint left on, they gained. Dried paint doesn't weigh as much anymore as it did in the past, due to different components and their weights, but it's not 500# or anything ridiculous. Fabric planes can lose a bunch of weight from the old dope/cotton to the synthetic systems.
We had a 185 come in once, and it gained almost 50# with the new paint job. We all agreed that something was amiss, so we opened up the belly inspection holes and it must've been through a flood or something, because the belly had about an inch of silt in the bottom of it!! I flushed that thing for about 3 days with water and I still didn't get it all out, but it was down closer to a "normal" weight.
John

I did find this in FAA-H-8083-1B Weight and Balance Handbook, about responsibility....

"Requirements
Regulations do not require periodic weighing of privately owned and operated aircraft. Such aircraft are usually weighed when originally certificated or after major alterations that can affect the weight and balance. The primary purpose of aircraft weight and balance control is safety. Manufacturers conduct extensive flight tests to establish loading limits for their aircraft because limit information is critical for safe flight.A secondary purpose is to aid efficiency during flight.Overloading of the aircraft is not the only concern; the distribution of the weight is important also. The aircraft has CG limits, and any loading that places the CG outside the established limits seriously impairs controllability of the aircraft.
Weight and balance is of such vital importance that each Federal Aviation Administration (FAA) certificated mechanic or repairman maintaining an aircraft must be fully aware of his or her responsibility to provide the pilot with current and accurate information for the actual weight of the aircraft and the location of the CG. The pilot in command (PIC) is responsible for knowing the weight of the load, CG, maximum allowable weight, and CG limits of the aircraft. The weight and balance report must include an equipment list showing weights and moment arms of all required and optional items of equipment included in the certificate empty weight.
Weight and balance records used in accounting for and correcting the CG location are reliable for only limited periods of time. For this reason, periodic aircraft weighing is desirable. An aircraft should be reweighed and a new weight and balance record should be started after the aircraft has undergone extensive repair or major alteration, when the pilot reports unsatisfactory flight characteristics (e.g., nose or tail heaviness), and when recorded weight and balance data are suspected to be in error.
Repairs and alterations are major sources of weight change. The airframe and powerplant (A&P) FAA-certificated mechanic or repairman who is responsible for making any repair or alteration must:
1. Establish by computation that the authorized weight and CG limits as shown in the type certificate data sheet (TCDS) and aircraft specifications are not exceeded, and
2. Record the new empty weight center of gravity (EWCG) data in the current approved aircraft flight manual or issued operating limitations.
When an aircraft has undergone extensive repair or major alteration, it should be reweighed and a new weight and balance record started. The A&P FAA-certificated mechanic or repairman responsible for the work must provide the pilot with current and accurate aircraft weight information and location of the EWCG.

"Should" is precatory. "Must" is mandatory. I agree - you really should know what your aircraft actually weighs. But your paperwork is legal if you compute, rather than weigh.

The real challenge with compliance happens away from base. Operating in remote locations often for several days at a time makes "knowing" the current W&B often just a guess. The pilot and crew at best can only estimate gear and fuel loads based upon pre-determined zone limits within the fuselage and how heavy things feel. Cessna in my experience tends to offer help with that method plus providing loading diagrams in their manuals. Just looking at the loaded plane while on floats and noting the waterline fore and aft can help. In the end it's experience that counts.....until then?

Gary

BC12D-4-85 said:

The real challenge with compliance happens away from base. Operating in remote locations often for several days at a time makes "knowing" the current W&B often just a guess. The pilot and crew at best can only estimate gear and fuel loads based upon pre-determined zone limits within the fuselage and how heavy things feel. Cessna in my experience tends to offer help with that method plus providing loading diagrams in their manuals. Just looking at the loaded plane while on floats and noting the waterline fore and aft can help. In the end it's experience that counts.....until then?

Gary

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Amazon.com: Rapala Tube Scale 50lb : Office Products

Randyk said:

Amazon.com: Rapala Tube Scale 50lb : Office Products

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Hah! Not hardly big enough Randy but I recall having them for weighing fish. BTW...how much does a 25hp Johnson with jet, fuel tank, and Achilles raft weigh? Plus complete field camp for two and 8 hrs fuel in a C-185 on floats. Fuel onboard is easy with a dipstick or in measured containers. Believe me there never was time for details - takes experience from prior flights. Of course today there's electronic flight bags that make the process smoother and more refined.

Gary

dgapilot said:

There is no empty weight limitation for a Light Sport aircraft (unless specifically identified by the manufacturer). The only limitation is gross weight. Of course, when the empty weight goes up, the useful load goes down. That's what often makes a single place airplane out of a two place airplane.

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I believe the rule for S-LSA is that the useful load must be equal to 190 times 2 plus 50% of the rated horsepower. So, for a Legend Cub that means the empty weight must be 890 punds or less. (190x2) = 380 plus 50 (half of 100) equals 430. 1320 is max gross for an LSA currently. 1320 minus 430 equals 890. Therefore the empty weight cannot exceed 890 pounds for an S-LSA.

E-LSA does not have to comply with this rule.

At least that’s the way it was when I bought the first Legend.

Rich

BC12D-4-85 said:

Hah! Not hardly big enough Randy but I recall having them for weighing fish. BTW...how much does a 25hp Johnson with jet, fuel tank, and Achilles raft weigh? Plus complete field camp for two and 8 hrs fuel in a C-185 on floats. Fuel onboard is easy with a dipstick or in measured containers. Believe me there never was time for details - takes experience from prior flights. Of course today there's electronic flight bags that make the process smoother and more refined.

Gary

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Well, if you weigh your equipment before going to the field, it won't change much on the way back..... And if your field harvest is less or equal to your field consumables, you're good to go..... Assuming the runway is long enough.....

^^^Such were the ways of the last century. Today there's an army of employees that make it happen for the pilot and crew. Some even still fuel their plane however.

Gary

I believe that twins operating 135 need to have periodic weigh ins, as do those working OAS flights.

Other than that I don't think there is a requirement for 135 to be on scales.

I see no reason to hold a customer Cherokee 6 hostage so it can be reweighed because a mechanic thinks it should be reweighed after strip and paint. They say I could loose at least 5 lbs on my plane if I would wash the mud off but the paint might come with it and I would loose my notoriety. 8)

Richgj3 said:

I believe the rule for S-LSA is that the useful load must be equal to 190 times 2 plus 50% of the rated horsepower. So, for a Legend Cub that means the empty weight must be 890 punds or less. (190x2) = 380 plus 50 (half of 100) equals 430. 1320 is max gross for an LSA currently. 1320 minus 430 equals 890. Therefore the empty weight cannot exceed 890 pounds for an S-LSA.

E-LSA does not have to comply with this rule.

At least that’s the way it was when I bought the first Legend.

Rich

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No such rule exists that I’ve been able to find.


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Richgj3 said:

I believe the rule for S-LSA is that the useful load must be equal to 190 times 2 plus 50% of the rated horsepower. So, for a Legend Cub that means the empty weight must be 890 punds or less. (190x2) = 380 plus 50 (half of 100) equals 430. 1320 is max gross for an LSA currently. 1320 minus 430 equals 890. Therefore the empty weight cannot exceed 890 pounds for an S-LSA.

E-LSA does not have to comply with this rule.

At least that’s the way it was when I bought the first Legend.

Rich

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dgapilot said:

No such rule exists that I’ve been able to find.

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I was under the same impression as Rich. It being part of the certification (or whatever they call it) requirements for S-LSA airplanes. This rule is how some manufacturers are able to install large horsepower engines and get away with it. They rate the engines for a very low maximum continuous power. Full power doesn't count since it is limited in time. So they can use for example, a 180 hp engine but rate it for 180 hp for one minute and 100 hp max continuous. Thus the ability to use 50 for the required useful load weight calculation.

dgapilot said:

No such rule exists that I’ve been able to find.


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That’s an ASTM requirement that applies to S-LSA only. The EAA write up doesn’t distinguish berweem “LSA” and S-LSA. A J3 Cub is an LSA. The rule does not apply to Cubs and such. An S-LSA is a a factory produced Light Sport Aircraft that was manufactured under the ASTM rules.

There was confusion at the beginning with manufacturers believing the useful load rule only needed to be met for the base airplane with no options installed. The rule was clarified to make its intention clear. Every S-LSA that leaves the factory has to comply.

Airplanes like J3 Cubs and Champs only have to comply with the gross weight limitation to be considered Light Sport and be operated by Sport Pilots. Likewise one can build an EAB and set the GW at 1320 and fly it as a Sport Pilot regardless of the empty weight however the DARs I know would be reluctant to license a two place home built with a GW of 1320 and an empty weight of 1100.

E-LSA does not have the EW/UL rule nor does it have the 51% rule which is why the LSA Cub clone market has move almost exclusively to airplanes licensed as E-LSA built at the factory with the owner/builder drinking coffee within twenty feet of the airframe

Rich

Richgj3 said:

The EAA write up doesn’t distinguish berweem “LSA” and S-LSA.

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There has always been a lot of confusion on this because of the way the FAA uses the term "LSA" to mean so many different things. The fact is, there is actually no reference in the certification rules to "Special Light-Sport Aircraft'. For certification purposes, the factory-built airplanes are certificated in the "Light-Sport" category, with the "purpose" being "airplane", "Weight-Shift", "Glider", "Balloon" or what have you. It is a Special airworthiness certificate in the Light-Sport category, so the industry and aviation community began referring to these as "Special Light-Sport Aircraft" or SLSA.

What we call "E-LSA" are certificated in the "Experimental" category, with the purpose being "operating a light-sport aircraft". That one is much more straightforward and easy for everyone to understand.

Where it really gets murky is on the sport pilot side. The FAA decided (in their almost infinite wisdom) to use the term "LSA" to mean ANY aircraft that meets the FAR 1.1 definition of a light-sport aircraft. These can be certificated in any airworthiness category, be it "Standard", "Light-Sport", or any number of "Experimental" categories including "operating light-sport aircraft", "operating amateur-built aircraft", "exhibition", etc. So what might be a "LSA" for pilot operating purposes may very well NOT be a LSA by certification.

Clear as mud, right?

Richgj3 said:

That’s an ASTM requirement that applies to S-LSA only. The EAA write up doesn’t distinguish berweem “LSA” and S-LSA. A J3 Cub is an LSA. The rule does not apply to Cubs and such. An S-LSA is a a factory produced Light Sport Aircraft that was manufactured under the ASTM rules.

There was confusion at the beginning with manufacturers believing the useful load rule only needed to be met for the base airplane with no options installed. The rule was clarified to make its intention clear. Every S-LSA that leaves the factory has to comply.

Airplanes like J3 Cubs and Champs only have to comply with the gross weight limitation to be considered Light Sport and be operated by Sport Pilots. Likewise one can build an EAB and set the GW at 1320 and fly it as a Sport Pilot regardless of the empty weight however the DARs I know would be reluctant to license a two place home built with a GW of 1320 and an empty weight of 1100.

E-LSA does not have the EW/UL rule nor does it have the 51% rule which is why the LSA Cub clone market has move almost exclusively to airplanes licensed as E-LSA built at the factory with the owner/builder drinking coffee within twenty feet of the airframe

Rich

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So you are saying it is part of the ASTM standard, and not a rule? One of the things I hate is if you want to see what is in the ASTM standard, you need to buy the standard.


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QUOTE=dgapilot;812353]So you are saying it is part of the ASTM standard, and not a rule? One of the things I hate is if you want to see what is in the ASTM standard, you need to buy the standard.[/QUOTE]

I believe that’s correct. I think there has always been confusion about “rules” in this environment. While FAA defines and regulates Sport Pilots and defines what they may operate, the manufacture of Light Sport Aircraft is not regulated directly by FAA. The manufacturer works under ASTM “rules”. The FAA has the oversight to audit them to insure they are following those rules. My Legend Cub was the first sold to a customer. It was the second “certified”. The AW certificate was issued from the FT. Worth MIDO. It says Special Light Sport Aircraft. Since then certain DARs have the authority to issue AW and I think that’s how Legend does it now.

I always thought this whole thing could be a bit more clear if we referred to aircraft that a Sport Pilot could operate as “Sport Pilot Eligible “ regardless of how it got there. Early on people had trouble understanding the Sport Pilot and LSA were separate concepts. Especially when it came to manufacturing. Using ASTM standards were/ are an attempt to make simple aircraft more economical to manufacture while still maintaining some level of standardization.

MOSAIC appears to be the extension of this concept but with broader application and more traditional FAA involvement.

Rich