Unless its an AD, you do not need update airworthy limitations

[astjp2]

Found this on the web while doing some research. One neat thing is that it applies to all FSDO's.

[Hank Jarrett]

OK, for anyone else who wanted to read the legal interpretation but hasn't typed the whole stupid address in since they put it in blue in a PDF (ONLY the FAA would do something like that!). Here is the link.

HTTPS://www.faa.gov/about/office_org/headquarters_offices/agc/practice_areas/regulations/interpretations/data/interps/2015/new-tennessee%20aircraft%20services%20-%20(2015)%20legal%20interpretation.pdf

Now all we need to do is translate all this into English!

Hank

[PA1195]

One question I've had previously pertains to STCs. What's the process for the STC holder to modify, obtain FAA approval, then notify STC users of changes? Lacking an AD-level of concern are there requirements for the STC holder to issue an alert?

Here is the answer, particularly § 21.99 (2)(b) as qualified by "may" not "shall": https://www.faa.gov/aircraft/air_cer...ponsibilities/

Gary - had lots of STC's and never have heard from an STC holder when known and published changes have occurred.

[Hank Jarrett]

OK, I think with a whole career using government documents i am at least passable at interpreting these things. Am I going senile or is the biggest pile of double talk since that guy tried to get me to buy an extended warranty on my car? Any lawyers here who can put this in English? The explanation is almost as bad as the document and my head hurts. We don't even have a factory or manufacturer in existence nor do we have an airworthiness limitations section (or even a document to contain it!)

Maybe I am just tired.

Hank

[PA1195]

"Once an aircraft is produced under a type certificate, the type design of that particular aircraft is fixed in time, absent an FAA requirement to make a retroactive change, or an owner's voluntary change (if it is approved under a method acceptable to the FAA(§ 21.95 for a minor change in type design) or if it is FAA-approved through a major change in type design (§ 21.97) or through a supplemental type certificate (STC) (§ 21.113(b))." Also applies to STC's and minor or major alterations.

Gary

[Hank Jarrett]

So if you keep a 46 BC12-D unmodified from the time it was manufactured follow-on changes sent out by the factory aren't required (for instance the clip on the fuel shut off that was added after the fact)? How does this impact OUR planes since there IS no factory any more? Does it mean that a plane that was upgraded to a later models specs have to follow the changes to the original design, the later one or none at all? More importantly if the change is a GOOD one that corrects a problem in the original design, wouldn't the owner be an idiot to not put it in even if not required by the FAA but asked for by the manufacturer? Wonder what this does to the liability of newer planes when say Cessna comes out with a change. Are they still liable if they say a change is needed but the FAA says you don't have to do it.

I am actually GLAD the factory doesn't put out changes to my planes any more. The legal an political types have created a mess and we would be stuck in it. I hope I am missing something obvious.

[3Dreaming]

So if you keep a 46 BC12-D unmodified from the time it was manufactured follow-on changes sent out by the factory aren't required (for instance the clip on the fuel shut off that was added after the fact)? How does this impact OUR planes since there IS no factory any more? Does it mean that a plane that was upgraded to a later models specs have to follow the changes to the original design, the later one or none at all? More importantly if the change is a GOOD one that corrects a problem in the original design, wouldn't the owner be an idiot to not put it in even if not required by the FAA but asked for by the manufacturer? Wonder what this does to the liability of newer planes when say Cessna comes out with a change. Are they still liable if they say a change is needed but the FAA says you don't have to do it.

I am actually GLAD the factory doesn't put out changes to my planes any more. The legal an political types have created a mess and we would be stuck in it. I hope I am missing something obvious.

Actually the clip is required because it is an AD. What this is dealing with is airworthiness limitations in the maintenance manual. Here is a hypothetical, In 1946 Taylorcraft had nothing other than a visual inspection of the wing struts for the airplane listed in the maintenance manual. In 1996 they decided that the struts need to be replaced every 10 years or 2000 hours on the new F series airplanes. At this time they decide to print a revision to the B model maintenance manual with the same limitation. Just because the limitation is printed in the new manual doesn't automatically make it apply to a B model airplane produced prior to 1996, unless the issue is addressed by a AD. For the earlier airplane you can use either the current manual and follow the limitation or the version that was issued at the time the airplane was produced with just the visual inspection. It takes an Airworthiness Directive to make following the newest version of the manual mandatory.

[PA1195]

It's prudent to follow service bulletins for the engine, airframe, accessories, parts, and propellers. Sourcing them can be a challenge. Same for STC's and alterations. The ICW that's sometime included on Form 337 as another source of methods and materials: https://www.faa.gov/documentLibrary/...r_8110.54A.pdf

As an owner I try to inform myself and have that available for my inspector so they can review and decide regarding compliance. Part 135 ops is different than our 91.

Gary

[astjp2]

Blade of grass is a prop strike for a lycoming, requires a complete tear down..you decide

[PA1195]

My responsibility as owner/operator: https://www.faa.gov/documentLibrary/...3-9C_CHG_2.pdf

I discuss with my A&P/IA the work performed but they have the final say as to entries in the maintenance records and return to service.

Gary

[3Dreaming]

Blade of grass is a prop strike for a lycoming, requires a complete tear down..you decide

You have to have a reduction in RPM or damage along with the blade of grass for it to be a prop strike.

[PA1195]

Having been through this once we decided to dial the crank runout and inspect the accessory drive gears. Prop appeared ok but I had driven through buried brush in deep snow while running my trapline. We also as a precaution sent the prop out for overhaul and a pitch and blade alignment check. Resistance to turning from ice and brush can affect blade shape especially at the tips. There was no sudden stoppage.

Edit: Nor were the crank, accessory gears, or prop (Mac 1A175/GM8242) adjusted from new. But then there were current records establishing that fact.

Gary