Reinstalling Original Cessna Seats

AK737pilot

AK737pilot

Pre-takeoff checklist
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Aug 20, 2017
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Wasilla, AK
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Chris
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Wolf Lake (4AK6)
Hello-

I just purchased a Cessna 182. Back in '97 the owners removed the back seat and installed Cessna 180/185 divided middle seats. I would like to reinstall the bench seat (more comfortable for the family). I have the 337 and weight and balance change forms.

Would another 337 and IA approval be required if I want to bring the airplane back to its original state? I'm thinking I'd be able to recalculate the weight and balance myself as an A&P.
 
If it were me, I'd just reinstall the original seat, record the work performed in the logbook and do a new weight and balance.
 
AK737pilot said:
Hello-

I just purchased a Cessna 182. Back in '97 the owners removed the back seat and installed Cessna 180/185 divided middle seats. I would like to reinstall the bench seat (more comfortable for the family). I have the 337 and weight and balance change forms.

Would another 337 and IA approval be required if I want to bring the airplane back to its original state? I'm thinking I'd be able to recalculate the weight and balance myself as an A&P.
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Yep !

To keep it legal another 337 should be filed.
 
Let's see what the FAA has to say.

From FAA Order 8300.16:

"Reversal of STC or Major Alteration. Occasionally, a request to remove an installed STC or major alteration may be made. When the alteration was originally accomplished, an FAA Form 337 and accompanying data was submitted to record the configuration change. Similarly, the restoration must be recorded via FAA Form 337, including consideration of any accompanying documentation used in the original alteration. If the original FAA Form 337 data included restoration instructions, then a new FAA Form 337 would not be required. In some cases, the original FAA Form 337 may have been submitted only to record approval of an AFMS. The removal of the supplement must be recorded via FAA Form 337 and may require ACO or ASI approval.

Note: For removal of a major alteration, whether installed by the manufacturer in production or post production by an STC, removal of the alteration requires an FAA Form 337 unless the removal instructions are provided with the STC or as part of the production."
 
Of course those of you who don't like when I or others quote the FAA, can simply ignore the above post.
 
SkyDog58 said:
Of course those of you who don't like when I or others quote the FAA, can simply ignore the above post.
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Can't speak for others but I thank you for posting.
 
SkyDog58 said:
Of course those of you who don't like when I or others quote the FAA, can simply ignore the above post.
Click to expand...

Interesting, thanks for posting that. I've always interpreted the STC or field approval for things like the OP's seat as giving an owner/operator an additional option for which configuration they desired to use, be it original or the newly approved one. Going off what you posted, my field approved skis would need a 337 every time they were removed and reinstalled, which of course has never happened since the original field approval to install them was obtained.

One would think something like this would be on the IA test, as far as I know it isn't.
 
mondtster said:
Interesting, thanks for posting that. I've always interpreted the STC or field approval for things like the OP's seat as giving an owner/operator an additional option for which configuration they desired to use, be it original or the newly approved one. Going off what you posted, my field approved skis would need a 337 every time they were removed and reinstalled, which of course has never happened since the original field approval to install them was obtained.

One would think something like this would be on the IA test, as far as I know it isn't.
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Your skis would not need an additional STC or 337 if the original STC or 337 provides instructions to switch back and forth. For skis, floats, bush wheels, etc., they frequently include such provisions. In that case, a simple log entry referencing the STC or 337 should suffice. But if the back and forth provision / instructions isn't included in the original approval then yes subsequent approval is required. At least that is my understanding.
 
SkyDog58 said:
Your skis would not need an additional STC or 337 if the original STC or 337 provides instructions to switch back and forth. For skis, floats, bush wheels, etc., they frequently include such provisions. In that case, a simple log entry referencing the STC or 337 should suffice. But if the back and forth provision / instructions isn't included in the original approval then yes subsequent approval is required. At least that is my understanding.
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Except it doesn't, nor do any of the big tire field approvals I've seen (my airplane has a field approval for them too). Hence my initial confusion, people remove and replace these items all the time and do no additional 337 even when there are no provisions to remove and install them. Not saying it's right, just saying that I have my doubts that many light airplane mechanics in this area know about that caveat.

Again, thanks for posting. I learned something important today.

EDIT: I found a copy of a 8.50 tire approval on a Cessna I'm familiar with. This airplane is currently sitting on 600-6 tires with no further 337. It has passed many annuals since the original field approval so either all the IAs are wrong or don't know any better.
 

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I can't see why you would worry,about installing original seats. How many mechanics worry about the rear seat during annual.
 
mondtster said:
If it were me, I'd just reinstall the original seat, record the work performed in the logbook and do a new weight and balance.
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Then the FAA would know your aircraft was modified, and it isn't. would the be airworthy when it is not configured IAW the history records for the aircraft?
 
AK737pilot said:
Hello-

I just purchased a Cessna 182. Back in '97 the owners removed the back seat and installed Cessna 180/185 divided middle seats. I would like to reinstall the bench seat (more comfortable for the family). I have the 337 and weight and balance change forms.

Would another 337 and IA approval be required if I want to bring the airplane back to its original state? I'm thinking I'd be able to recalculate the weight and balance myself as an A&P.
Click to expand...
Any time an aircraft is modified by a 337 installing or removing equipment it must be un-modified by a 337 removing the STC or field approved modification.

the 337 form is the only method of informing the FAA of modifications, or major repairs.
 
mondtster said:
Except it doesn't, nor do any of the big tire field approvals I've seen (my airplane has a field approval for them too). Hence my initial confusion, people remove and replace these items all the time and do no additional 337 even when there are no provisions to remove and install them. Not saying it's right, just saying that I have my doubts that many light airplane mechanics in this area know about that caveat.

Again, thanks for posting. I learned something important today.

EDIT: I found a copy of a 8.50 tire approval on a Cessna I'm familiar with. This airplane is currently sitting on 600-6 tires with no further 337. It has passed many annuals since the original field approval so either all the IAs are wrong or don't know any better.
Click to expand...

the entry that will get you in trouble fast is "updated weight an balance and equipment list." if you do not change those and submit a new 337 you are flying an un-airworthy aircraft.

bob
 
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