Changing Max Gross on an Experimental?

idahoflier

idahoflier

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idahoflier
Has anyone gone through the process and changed the Max Gross on an experimental? Just curious how much of a pain it is to jump through those hoops?

I'm considering building an experimental (Zenith 7xx series) that could have a higher max gross than the LSA 1,320 LB limit. If I find myself in the future being forced to fly as a SP I would want to change the max gross of the aircraft to 1,320 LB at that time...
 
Per 14CFR 1.1:
Light-sport aircraft means an aircraft, other than a helicopter or powered-lift that, since its original certification, has continued to meet the following:

(1) A maximum takeoff weight of not more than—

(i) 1,320 pounds (600 kilograms) for aircraft not intended for operation on water; or

(ii) 1,430 pounds (650 kilograms) for an aircraft intended for operation on water.
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It has to meet LSA weight requirements “since it’s original certification”, so a weight change to meet LSA isn’t possible.
 
What’s stopping you from removing the data plate and creating a new one and going through the entire process again? Obviously you’d have to have the dar inspections and re fly the phases.
 
Salty said:
What’s stopping you from removing the data plate and creating a new one and going through the entire process again? Obviously you’d have to have the dar inspections and re fly the phases.
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Assuming I could do that, it's more hoop jumping than I would want to contend with...
 
If it's registered as experimental amateur built than you as the owner can put it back into flight testing with a letter to the FSDO in order to test and set the gross weight to whatever you want it to be. There is no data plate or any paperwork that says what the max gross weight is on an exoerimental. You are just limited to what it us tested to. If it's a factory built LSA then you can not.
 
Wouldnt the easy solution be to treat the 1320 as a paperwork limit. I assume theres numbers for the higher gross weight just use those and dont put 2 300lb guys and luggage and full tanks and depart in front of an ASI. Im all for rule following but if the plane is tested to the higher limits and other builds use higher limits with no problem i dont see any safety concerns, and any legal concerns are remote.
 
falconkidding said:
Wouldnt the easy solution be to treat the 1320 as a paperwork limit. I assume theres numbers for the higher gross weight just use those and dont put 2 300lb guys and luggage and full tanks and depart in front of an ASI. Im all for rule following but if the plane is tested to the higher limits and other builds use higher limits with no problem i dont see any safety concerns, and any legal concerns are remote.
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I'm not going to say that thought had never crossed my mind and while I have never done it, I know pilots have flown their aircraft over gross. That said, I think it would be a huge problem from both enforcement and liability perspectives if I did intentionally fly the aircraft over gross and had an accident.
 
kmacht said:
If it's registered as experimental amateur built than you as the owner can put it back into flight testing with a letter to the FSDO in order to test and set the gross weight to whatever you want it to be. There is no data plate or any paperwork that says what the max gross weight is on an exoerimental. You are just limited to what it us tested to. If it's a factory built LSA then you can not.
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See post # 2 as MauleSkinner is correct. The OP is seeking to lower the gross weight in order to make it LSA compliant. That is not allowed under the Light Sport rules.
 
As others have said, you can't lower the GW and then fly it as a SP. But if you're building it, you can set it to 1320 initially, then raise it later if MOSAIC ever gives a LSA weight increase. Might even be passed before you get the build done.
 
MauleSkinner said:
It has to meet LSA weight requirements “since it’s original certification”, so a weight change to meet LSA isn’t possible.
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Per the OP he's considering building, not already built. Each Ex/AB certified *used* to be considered the first of it's type and my DAR made sure the type listed on my airworthiness cert reflected that. If that's still the case then if the OP lists the 'new' GW prior to cert it would meet the requirement you posted.

Nauga,
spelled 'Throat-warbler Mangrove' but pronounced 'RV-4'
 
nauga said:
Per the OP he's considering building, not already built. Each Ex/AB certified *used* to be considered the first of it's type and my DAR made sure the type listed on my airworthiness cert reflected that. If that's still the case then if the OP lists the 'new' GW prior to cert it would meet the requirement you posted.

Nauga,
spelled 'Throat-warbler Mangrove' but pronounced 'RV-4'
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True, but I got the impression he was talking about certifying it at the heavier weight, and then maybe changing the weight limit later on.
 
Daleandee said:
See post # 2 as MauleSkinner is correct. The OP is seeking to lower the gross weight in order to make it LSA compliant. That is not allowed under the Light Sport rules.
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Gross weight is set by the builder and can be changed by the builder in an experimental. The info that maulskinner posted does not apply to amateur built experimental aircraft only to LSA certified aircraft.
 
kmacht said:
Gross weight is set by the builder and can be changed by the builder in an experimental. The info that maulskinner posted does not apply to amateur built experimental aircraft only to LSA certified aircraft.
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I think you're probably right about being able to change the gross weight, but unless the FAA views that the act of re-certifying an experimental turns it into an "original" aircraft, that probably won't work per the definition @MauleSkinner provided...
 
I appreciate everyone's thoughts and feedback, thanks!
 
kmacht said:
Gross weight is set by the builder and can be changed by the builder in an experimental. The info that maulskinner posted does not apply to amateur built experimental aircraft only to LSA certified aircraft.
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Yes ... but lowering the gross to fit into the light sport category is exactly what the OP was asking about and for purposes of Light Sport that cannot be done. Doesn't matter if the plane is experimental or certified (some attempted this with Luscombes and it was rejected).

If a plane is going to be operated as complying with light sport then what was posted in post # 2 does apply.
 
Daleandee said:
If a plane is going to be operated as complying with light sport then what was posted in post # 2 does apply.
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Yes, and if his airworthiness cert says it's an e.g. "Idahoflier Zenith 7xx" then it is the first cert of its type and he can set the gross weight to LSA limit and be compliant if he chooses. He cannot, however, set it higher on initial cert and later reduce it to be LSA compliant. Ex/AB airplanes are not type certificated and have no assurance of any compliance with the kit producers design, so each airplane is (or used to be) treated as a different type.

Nauga,
limited
 
MauleSkinner said:
Per 14CFR 1.1:

It has to meet LSA weight requirements “since it’s original certification”, so a weight change to meet LSA isn’t possible.
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Experimentals are not certificated. Even on certificated aircraft, the FAA is starting to weasel on the "since original" part.

Gross weight change on an experimental requires a notification of the FAA. The FAA may require an additional test period as a result, but I can't imagine shrinking the envelope would cause much attention.
 
idahoflier said:
Just curious how much of a pain it is to jump through those hoops?
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FYI: Your best route for those answers will be from a DAR with LSA function codes. While an E/AB is not produced under a TC it does go through an airworthiness certification process to receive its Special Airworthiness Certificate. There are a number of FAA references to this point. So you'll find the meaning of "since its original certification" applies to when it received its original airworthiness certificate. "Original certification" also has implications in the TC world and is based on when the aircraft receives its AWC and not when it rolled off the assembly line.
 
Daleandee said:
Yes ... but lowering the gross to fit into the light sport category is exactly what the OP was asking about and for purposes of Light Sport that cannot be done. Doesn't matter if the plane is experimental or certified (some attempted this with Luscombes and it was rejected).

If a plane is going to be operated as complying with light sport then what was posted in post # 2 does apply.
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Sure it can. It just needs to be formally put back into phase 1 flight testing. The gross weight is not set during the airworthiness certification on an experimental like it is for most other airplanes including the luscombe you mention. What if you decide to build and install a new wing design for your already flying experimental airplane or decide to remove a structural support. Say that wing no longer supports more than the LSA limit. You just need to put the plane back into phase 1 flight testing with a letter to the FSDO, test fly it and record the new limit it was tested to. If the new limits are all within the LSA requirements you can go fly it with only a sport pilots license. The difference is that the plane has an experimemtal airworthy Ed’s certificate that does not tie to any originally certified gross weight as gross weight is not determined before certification in the experimental world.
 
kmacht said:
The gross weight is not set during the airworthiness certification on an experimental like it is for most other airplanes including the luscombe you mention.
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I'm done debating this but I do want to point out that while the gross is not on the AW, the gross weight is declared (W&B report) and the experimental aircraft is required to be tested to that weight.
 
Daleandee said:
I'm done debating this but I do want to point out that while the gross is not on the AW, the gross weight is declared (W&B report) and the experimental aircraft is required to be tested to that weight.
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Nope. Empty weight and CG is reported on the weight and balance report at the time of certification of an experimental. Gross weight is not. When I went through the airworthiness inspection on my sonex I did not have a gross weight listed anywhere on the paperwork. It was only listed in my aircraft manual and added to the weight and balance report once I flight tested to various weights and cg locations.
 
kmacht said:
Nope. Empty weight and CG is reported on the weight and balance report at the time of certification of an experimental. Gross weight is not. When I went through the airworthiness inspection on my sonex I did not have a gross weight listed anywhere on the paperwork. It was only listed in my aircraft manual and added to the weight and balance report once I flight tested to various weights and cg locations.
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Point taken. Still my DAR required me to have CG & W&B numbers for empty, gross, full forward CG, full aft CG, and for my first flight. We went over many loading scenarios and he made me "show my work." Perhaps this was due to the fact that I claimed a higher gross than the kit manufacturer gave ...
 
Daleandee said:
Point taken. Still my DAR required me to have CG & W&B numbers for empty, gross, full forward CG, full aft CG, and for my first flight. We went over many loading scenarios and he made me "show my work." Perhaps this was due to the fact that I claimed a higher gross than the kit manufacturer gave ...
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Some of the difference in the paperwork could be that I scratch built and did not buy the kit from Sonex. I did test up to 1300lbs but with the aerovee I would not recommend it unless perfect conditions and a very long runway.

Good conversation. Maybe one day we will get a chance to meet up and see each others planes.
 
kmacht said:
Some of the difference in the paperwork could be that I scratch built and did not buy the kit from Sonex. I did test up to 1300lbs but with the aerovee I would not recommend it unless perfect conditions and a very long runway.

Good conversation. Maybe one day we will get a chance to meet up and see each others planes.
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I had an Aerovee Sonex that I tested to 1150 lbs. On a cool morning it wasn't stellar but it wasn't frightening either. Pretty sure I'd never do 1300 with an Aerovee ...

BTW, my hat is off to scratch builders!
 
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