Can a STC be removed?

[CharlieD3]

So, if you purchase an aircraft that has an STC that increases gross weight... say from over the limit for Basic Med down the original certified gross of 6000 pounds? I.E.:

Original gross: 6000#
STC Gross: 6750#
Remove STC, revert to 6000# gross.

 

[Jeff Oslick]

If it involved a structural change, that could be complicated, as the STC holder may not have considered the implications of removing new structure.

If it is paperwork-only (such as the MGTOW STC for 182Ps and Qs), I'd think a new 337 indicating removal of STC and revision of the aircraft W&B and POH records would be all that is needed.

 

[Bell206]

Remove STC, revert to 6000# gross.

Technically any STC can be removed. How that is performed and with what additional paperwork requirements depends on how the STC was installed originally. For example, some STCs include restoration instructions which simplifies everything when removing an STC. However, I dont know if there is a provision with Basic Med aircraft about weight limit modifications as there is for LSA aircraft max limit mods.

 

[CharlieD3]

I know that, for example, if you buy a Cherokee 6 with the 7th seat, you have to remove it, and do some paperwork because Basic Med limits you to 6 souls aboard.

I don't know if the aircraft STC for this target aircraft with the weight STC has any structural component to the STC... Otherwise I would hope it is as Jeff said...

 

[k9medic]

The Cherokee 6 has a seventh seat STC which is actually an STC to remove it. Thankfully it is a free STC. "All a PA–32 owner needs to do is receive a copy of the supplemental type certificate (STC) and letter of authorization from AOPA that allows certain PA–32 models, certified with an option for seven seats, to be flown as six-seat-restricted aircraft."

If I took the VG's off my 310 or my 421, I would have the mechanic write it up and show that the STC was removed. He would have to do a 337 though.

 

[Bell206]

I know that, for example, if you buy a Cherokee 6 with the 7th seat, you have to remove it, and do some paperwork because Basic Med limits you to 6 souls aboard.

The part I was referencing is I don't know if once you alter an aircraft above the 6000lb limit whether it would still qualify for Basic Med even if you legally return it back to the 6000lb limit. I believe with an LSA eligible aircraft like a Champ if at any time since its original certification it was altered to a max gross above 1320 it can no longer qualify as a LSA even if returned to a lower gross weight. Don't know if something similar applies to Basic Med as well or if you can simply restore the gross weight back to original.

 

[CharlieD3]

Ahh.. I see now.... Hmmm. I wonder..

 

[Dana]

According to Advisory Circular AC68-1A:

5.1.2 Type Certificated Aircraft. For type certificated aircraft, the aircraft’s design approval would authorize the number of occupants the aircraft may carry and would contain the maximum certificated takeoff weight. The aircraft’s design approval may be a type certificate (TC), a supplemental type certificate (STC), or an amended TC (ATC). The FAA recognizes that changes could be made to an aircraft’s type design. For example, an aircraft type certificated to carry more than six occupants may be altered to carry six or fewer occupants. In order to make such a change, that aircraft would have to obtain a new design approval, such as an STC or an ATC. So long as an aircraft’s design approval (i.e., TC, STC, or ATC) authorizes the aircraft to carry no more than six occupants, that aircraft would meet the requirements of § 61.113(i)(1). Additionally, if an aircraft with a maximum certificated takeoff weight of more than 6,000 pounds is altered to have a maximum certificated takeoff weight of less than 6,000 pounds, then that aircraft would likewise meet the requirements of § 61.113(i)(1).​

​

(italics mine) So yes, you can fly under basicmed with an aircraft that has had the weight reduced by STC, or removal of an STC. It doesn't have the stupid "continuously met the requirements" of Sport Pilot/LSA.

 

[Chrisgoesflying]

Even before the rules change, some airplanes would have qualified as LSA without a specific STC but don't with the specific STC. The only example I know is the Ercoupe. The Ercoupe C qualifies as LSA. However, the Ercoupe D does not. Many people, prior to LSA, converted their Ercoupe C to an Ercoupe D to get a few pounds of extra useful load. Then, LSA came along and people wanted to convert back to the original C model but weren't able to. I don't know enough about this so I may be wrong, but from my understanding, nothing had to be done to the plane to go from C to D, besides paperwork.

 

[Bell206]

The only example I know is the Ercoupe.

There were other models that were sub-1320lbs originally but had higher gross weight options as well. Here's one list. In the case of the 415 there were several minor alterations that were needed to go to a D-model vs a simple paperwork exercise. However, as I recall there were some lucky individuals who were able to convert their D-models back to a C-model for LSA ops via a field approval process. Unfortunately, not all FSDOs provided the same support.

 

[Daleandee]

So yes, you can fly under basicmed with an aircraft that has had the weight reduced by STC, or removal of an STC. It doesn't have the stupid "continuously met the requirements" of Sport Pilot/LSA.

I agree! That requirement under the Sport rules is just stupid!

 

[Half Fast]

Even before the rules change, some airplanes would have qualified as LSA without a specific STC but don't with the specific STC. The only example I know is the Ercoupe. The Ercoupe C qualifies as LSA. However, the Ercoupe D does not. Many people, prior to LSA, converted their Ercoupe C to an Ercoupe D to get a few pounds of extra useful load. Then, LSA came along and people wanted to convert back to the original C model but weren't able to. I don't know enough about this so I may be wrong, but from my understanding, nothing had to be done to the plane to go from C to D, besides paperwork.

Yep, but I think when MOSAIC is approved those D models, including the STC conversions, will become LSA qualified again. And if so, everyone with a C will be rushing to get the STC for the higher weight.

 

[CharlieD3]

According to Advisory Circular AC68-1A:

5.1.2 Type Certificated Aircraft. For type certificated aircraft, the aircraft’s design approval would authorize the number of occupants the aircraft may carry and would contain the maximum certificated takeoff weight. The aircraft’s design approval may be a type certificate (TC), a supplemental type certificate (STC), or an amended TC (ATC). The FAA recognizes that changes could be made to an aircraft’s type design. For example, an aircraft type certificated to carry more than six occupants may be altered to carry six or fewer occupants. In order to make such a change, that aircraft would have to obtain a new design approval, such as an STC or an ATC. So long as an aircraft’s design approval (i.e., TC, STC, or ATC) authorizes the aircraft to carry no more than six occupants, that aircraft would meet the requirements of § 61.113(i)(1). Additionally, if an aircraft with a maximum certificated takeoff weight of more than 6,000 pounds is altered to have a maximum certificated takeoff weight of less than 6,000 pounds, then that aircraft would likewise meet the requirements of § 61.113(i)(1).​

​

(italics mine) So yes, you can fly under basicmed with an aircraft that has had the weight reduced by STC, or removal of an STC. It doesn't have the stupid "continuously met the requirements" of Sport Pilot/LSA.

Thanks! That answers my question!