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LSA 'Maximum Empty Weight' clarification

CubCrafters

Registered User
A customer just sent me a note that the topic of S-LSA certification was being discussed on your site. He sent me a few of the posts, and I think I can contribute by clearing up some misinformation on the Maximum Empty Weight issue for S-LSA aircraft. We have been getting a lot of calls here at CubCrafters about this as well, so apparently there is considerable confusion and/or concern around the topic.

First, you can go to FAR Part 21, Subpart H Airworthiness Certificates, Section 21.190: Issue of a special airworthiness certificate for a light-sport category aircraft to see where the requirements to issue an S-LSA airworthiness certificate are detailed. Those places in that FAR where “meeting the consensus standard” are called out are in reference to the agreed upon ASTM Standards on Light Sport Aircraft. I am pretty sure all of this information is publicly available.

In short, the Maximum Empty Weight of a 2-place, 100hp, S-LSA on wheels cannot exceed 890 Lbs in any configuration, including the weight of all optional equipment. The Maximum Gross Weight for that airplane is 1,320 Lbs. If that same airplane is equipped for float operations (i.e. floats are installed), the Maximum Empty Weight is 1,000 Lbs and the Maximum Gross Weight is 1,430 Lbs for that float-equipped airplane. All of this information, including the correct formulas and calculations, can be found in much greater detail in ASTM 2245: Standard Specification for the Design and Performance of a Light Sport Airplane. ASTM 2245 is one of several of the “consensus standards” that a manufacturer must comply with to legally certify S-LSA aircraft.

Interestingly, there is more urgent information on the subject that you may not be aware of coming from the FAA, EAA, and the LSA industry trade group LAMA (the Light Aircraft Manufacturer’s Association). Each seems very concerned about compliance with this particular Maximum Empty Weight limitation for S-LSA. LAMA sent this “Industry Alert” out below - only the second one it has ever issued - to all LSA manufacturers just a few weeks ago on 7.25.07. The “Alert” not only clarifies the certification requirements around weight, but it raises the issue of “non-compliance status and FAA action for both new and existing S-LSA aircraft” if those aircraft ARE NOT in compliance with the Maximum Empty Weight specification or any other certification requirement. Questions are already being raised about how an S-LSA airplane (100hp, 2-place) that weighs more than 890 Lbs empty is “legal” or is going to pass its annual condition inspection, but in our case, every CubCrafters S-LSA produced has come under the Maximum Empty Weight certification limit.

LAMA_Ind_Alert_July_07.JPG


Thanks,
Todd Simmons
President, CubCrafters
 
I see American Champion got around this with the new Champ was to certify it to Part 23 standards. I guess the 950 lb empty weight made the
LSA standards impossible to meet.
 
The Empty weight formula only applies to S-LSA airplanes.
These are new manufacture airplanes built under the ASTM standard, not under FAR 23 (or CAR 3 for the older airplanes)

DaveG
 
Legend in excess of 890

I have been lurking on the sidelines for a couple of years - lot's of great information gleaned from this site to date.

This issue spurred me to officially jump in.

I currently own a Legend Cub that has an empty weight in excess of 930+ lbs empty weight, and the paperwork says S-LSA and ASTM certified. Does anyone else have a Legend that has an empty weight above 890? Now what?
 
I may be incorrect, but I was told that many Legend Cubs do not comply with this rule. What is the status of these aircraft, are they not airworthy?
 
ksecub said:
I may be incorrect, but I was told that many Legend Cubs do not comply with this rule. What is the status of these aircraft, are they not airworthy?

I figured that is why Todd started this thread.
 
Steve Pierce said:
ksecub said:
I may be incorrect, but I was told that many Legend Cubs do not comply with this rule. What is the status of these aircraft, are they not airworthy?

I figured that is why Todd started this thread.

So what's the answer to ksecub's question? It seems to me that Mr. Simmons posted relevant information that had been questioned on another thread. Subsequently a Legend Cub owner noted that his airplane exceeds the prescribed weight. Is there reason for the Legend Cub owner to be concerned? What's the answer?

I appreciated Mr. Simmons' post. It was articulate, factual, and in no way attacked anybody. He shared his technical knowledge for the benefit of guys like me that didn't know. Bravo.

Stewart
 
Tim, I can't imagine a PA-11 weighing 900 pounds empty. That sounds at least 100 pounds heavy to me.
JimC
 
Stewart, Are you saying I attacked Todd? I just want to know the answer just like you. I know all of these airplanes have been tested to at least 1600 to 1650 lbs. so the 1320 is meaningless to me except the legalities of it all. Todd quoted where his info came from and Joe Norris with EAA did not. Long, long day yesterday and I was to lazy to start my own research. I figure Joe and Todd know the answer.
 
JimC said:
Tim, I can't imagine a PA-11 weighing 900 pounds empty. That sounds at least 100 pounds heavy to me.
JimC

Jim-

I saw a PA-11 that was IFR approved, I think it came in at 930 or something!!
 
Steve Pierce said:
Stewart, Are you saying I attacked Todd? I just want to know the answer just like you. I know all of these airplanes have been tested to at least 1600 to 1650 lbs. so the 1320 is meaningless to me except the legalities of it all. Todd quoted where his info came from and Joe Norris with EAA did not. Long, long day yesterday and I was to lazy to start my own research. I figure Joe and Todd know the answer.

From the legend site:

*Please note that all light-sport certified aircraft must comply with maximum empty weight standards. As such, there are limits to what options may be chosen for a particular aircraft. The list above illustrates the wide range of options available on the Legend Cub. Please contact the factory to discuss the range of possibilities for your specific needs.

**Stall speed when equipped with vortex generators is 35 mph (CAS).

Note: Specifications subject to change.
 
StewartB said:
So what's the answer to ksecub's question?

Hi Stewart,

The answer to ksecub's question is that nobody knows yet what is going to happen to those airplanes. It's pretty easy to see that they do not meet the standard. As such, they are not eligible for an airworthiness certificate in the Light Sport category (commonly referred to as "SLSA").

However, the fact is that they DO have an airworthiness certificate in the Light Sport category, so the FAA would have to initiate legal proceedings to revoke the certificate. Lots of finger pointing would ensue, because the FAA itself (though the inspector or DAR who performed the airworthiness inspection) would be at fault for issuing an invalid airworthiness certificate. A quick check of the weight and balance report by the inspector would have avoided the whole mess, so the FAA has some liability for the error. (I check each and every SLSA application I get to make sure the W&B comes out right.)

The bottom line is, the aircraft have a valid airworthiness certificate until the FAA says otherwise. To date the FAA has not made an issue of these aircraft that don't meet the standard for useful load, and I have not heard any rumblings that they are planning to do anything. I'm sure FAA legal has bigger fish to fry, so unless this issue comes to light as a major safety concern I doubt they'll do anything. Of course times change, so this might become an issue in the future.

I will be down in Oklahoma City all week next week, helping to train new DAR candidates AND FAA inspectors on LSA certification. This issue will be one of many that will be discussed. Hopefully as more inspectors become more knowledgeable, less aircraft will be improperly certificated.
 
DaveG said:
The Empty weight formula only applies to S-LSA airplanes. These are new manufacture airplanes built under the ASTM standard, not under FAR 23 (or CAR 3 for the older airplanes)

That's correct. This minimum useful load requirement only applies to aircraft certificated in the Light Sport category (commonly called "SLSA") under 14 CFR 21.190. It does not apply to aircraft certificated in other categories, including standard category airplanes like Cubs & Champs (or experimental amateur-built, experimental exhibition, experimental light-sport conversions under 21.191(i)(1), etc.)
 
jnorris said:
StewartB said:
So what's the answer to ksecub's question?

Hi Stewart,

The answer to ksecub's question is that nobody knows yet what is going to happen to those airplanes. It's pretty easy to see that they do not meet the standard. As such, they are not eligible for an airworthiness certificate in the Light Sport category (commonly referred to as "SLSA").

However, the fact is that they DO have an airworthiness certificate in the Light Sport category, so the FAA would have to initiate legal proceedings to revoke the certificate. Lots of finger pointing would ensue, because the FAA itself (though the inspector or DAR who performed the airworthiness inspection) would be at fault for issuing an invalid airworthiness certificate. A quick check of the weight and balance report by the inspector would have avoided the whole mess, so the FAA has some liability for the error. (I check each and every SLSA application I get to make sure the W&B comes out right.)

The bottom line is, the aircraft have a valid airworthiness certificate until the FAA says otherwise. To date the FAA has not made an issue of these aircraft that don't meet the standard for useful load, and I have not heard any rumblings that they are planning to do anything. I'm sure FAA legal has bigger fish to fry, so unless this issue comes to light as a major safety concern I doubt they'll do anything. Of course times change, so this might become an issue in the future.

I will be down in Oklahoma City all week next week, helping to train new DAR candidates AND FAA inspectors on LSA certification. This issue will be one of many that will be discussed. Hopefully as more inspectors become more knowledgeable, less aircraft will be improperly certificated.


So with that being said, I guess you will never be able to put bushwheels or skis, etc. on a light sport due to the fact that it might put it over the 890 number.

Tim
 
Joe,

Thanks very much for the information. It'll be interesting to see how this situation is dealt with.

Stewart
 
>I saw a PA-11 that was IFR approved, I think it came in at 930 or something!!<

Wow!. Mine weighed 734 pounds. That's a lot of difference.
JimC
 
More concerns

As previously posted, my Legend is quite over the 890 lbs. It is due for it's annual condition inspection next month. In speaking with my A&P/IA last night he said he would never sign off my airplane for an annual condition inspection unless it weighed 890 or less. He felt he would be in "violation" of the FAR's that govern his certificate. Arghhhh.. Guess I will have to go shopping for a new A&P, or figure out how to take 40 lbs out of this airplane......

I wonder if I have a valid airworthiness now since I know my airplane is "too heavy". I am sure there is a catch-all FAR that makes me the responsible person right now....am I in "violation" of some FAR when I operate the airplane?

I also wonder if there is an accident can my insurance carrier deny my claim since I am operating this "overweight" airplane?

Not a real happy camper right now.
 
Re: More concerns

dskseller said:
As previously posted, my Legend is quite over the 890 lbs. It is due for it's annual condition inspection next month. In speaking with my A&P/IA last night he said he would never sign off my airplane for an annual condition inspection unless it weighed 890 or less. He felt he would be in "violation" of the FAR's that govern his certificate. Arghhhh.. Guess I will have to go shopping for a new A&P, or figure out how to take 40 lbs out of this airplane......

I wonder if I have a valid airworthiness now since I know my airplane is "too heavy". I am sure there is a catch-all FAR that makes me the responsible person right now....am I in "violation" of some FAR when I operate the airplane?

I also wonder if there is an accident can my insurance carrier deny my claim since I am operating this "overweight" airplane?

Not a real happy camper right now.

I'd be calling the manufacturer, particularly if I was the original purchaser. If I bought an airplane that was issued an airworthiness certificate but was ineligible for continued airworthiness by no fault of anyone but the manufacturer? I'd be a little unhappy as well. Best wishes for finding a resolution. I mean that sincerely.

Stewart
 
Re: More concerns

dskseller said:
As previously posted, my Legend is quite over the 890 lbs. It is due for it's annual condition inspection next month. In speaking with my A&P/IA last night he said he would never sign off my airplane for an annual condition inspection unless it weighed 890 or less. He felt he would be in "violation" of the FAR's that govern his certificate. Arghhhh.. Guess I will have to go shopping for a new A&P, or figure out how to take 40 lbs out of this airplane......

I wonder if I have a valid airworthiness now since I know my airplane is "too heavy". I am sure there is a catch-all FAR that makes me the responsible person right now....am I in "violation" of some FAR when I operate the airplane?

I also wonder if there is an accident can my insurance carrier deny my claim since I am operating this "overweight" airplane?

Not a real happy camper right now.

Whats in your overweight airplane? I know they had those things advertised with metal props, leather interior, bunches of radios..etc.
 
Legend Equipment

yellow, closed cowl, spin on oil filter, air/oil sep, metal prop, com, trans, encoder, intercom, strobes/position lights, 800 x 6 tires
 
behindpropellers said:
So with that being said, I guess you will never be able to put bushwheels or skis, etc. on a light sport due to the fact that it might put it over the 890 number.

That's no doubt true. Also remember that NO modifications to be made to an SLSA without specific permission instructions from the aircraft manufacturer. There's no such thing as "field approvals" or "STCs" for SLSA aircraft. Everything has to be approved by the manufacturer in some fashion.

For modifications that the manufacturer will not support, the only option would be to surrender the SLSA airworthiness certificate and have the aircraft re-certificated in the experimental LSA category (Ref: 21.191(i)(2)). Once the aircraft is converted to experimental it is treated like any other experimental LSA and you can make any modifications you want (and can have any empty weight you want).
 
behindpropellers said:
So with that being said, I guess you will never be able to put bushwheels or skis, etc. on a light sport due to the fact that it might put it over the 890 number.

One more thing. The 890 lb empty weight number only applies to a two seat aircraft with a 100 hp engine. Aircraft with engines of more or less than 100 hp will have a different "magic" number. This is due to the formula that's called out in the consensus standard for minimum useful load, which is 190 lbs per seat plus a number equal to half the maximum horsepower of the engine. So, for a two seat aircraft with a 100 hp engine the formula comes out as 190+190+50=430 lbs. 1320 lbs minus 430 lbs equals 890 lbs.

But for an aircraft with a 120 hp engine the formula would be 190+190+60, which equals 440 lbs. So the maximum empty weight of an SLSA with a 120 hp engine would be 880 lbs. By the same formula, a two-seat aircraft with an 80 hp engine could have an empty wight as high as 900 lbs, and the same aircraft with a 65 hp engine could have an empty weight as high as 907.5 lbs and still be in compliance.

As you can see, a single seat aircraft has even more flexibility. A single seater with a 100 hp engine could have an empty weight as high as 1080 lbs (assuming a 1320 maximum gross).

But for our beloved Cub "replicas" with an O-200 the magic number is 890 lbs empty.

Cheers!
 
I have a relatively basic CC11 that weighs 870# with 26" LSA Bushwheels (fantastic tires!! from AK Bushwheels). I use it like a cub and appreciate the way it flies. CubCrafters, love them or hate them, has spent millions to develop carbon fiber, and other light-weight technology to keep this aircraft legal and under the 890# limit.... and the aircraft continues to improve ... apparently, the Carbon Cub really was a research and development aircraft which explored more lightweight technologies. If Continental will do their part by upgrading this 50 year old engine and carburetor....it will be the perfect legal aircraft for my mission.... I maintain my PPL... chose CC11 because I fell in love with the airplane.
 
jnorris said:
For modifications that the manufacturer will not support, the only option would be to surrender the SLSA airworthiness certificate and have the aircraft re-certificated in the experimental LSA category (Ref: 21.191(i)(2)). Once the aircraft is converted to experimental it is treated like any other experimental LSA and you can make any modifications you want (and can have any empty weight you want).

Joe,

I don't get it. If the process of converting from S-LSA to Experimental LSA is relatively easy, what possible disadvantage could there be in doing so? I'd think the experimental designation would be preferable. Am I missing something?

Stewart
 
Stewart,

I'm betting the one word that is the single largest factor in all experimental category aircraft: Liability
Ask the guy who sold John Denver the exp. aircraft about that one.

But, this also begs the question regarding switching from SLSA certified to Experimental LSA. You can't just switch a certified airplane over to Experimental, can you do that with an SLSA??

MTV
 
StewartB said:
I don't get it. If the process of converting from S-LSA to Experimental LSA is relatively easy, what possible disadvantage could there be in doing so? I'd think the experimental designation would be preferable. Am I missing something?

The two biggest issues would be that the experimental LSA would no longer be eligible for any "for-hire" usage (an instructor could no longer give flight instruction for hire in the aircraft that he/she provides, nor could you have it on the rental line at the local FBO) and insurance rates.

For an individual owner who doesn't care about the "for-hire" aspect of the certification and can get decent insurance rates, the experimental route might be worth pursuing at some point. I wouldn't recommend it yet though, as the FAA still has some "tweaking" to do on the regulations regarding maintenance requirements of these SLSA that are converted to ELSA. That's a long story that I'm not going to type here, but right now it is an issue that the FAA needs to fix.
 
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