100 hour inspections in logbooks

[rturbett]

Is it fair to assume that when you see 100 hour inspections in the logbooks, the plane has been used as a rental?   

 

Anything else that may result in 100hr inspections showing up in the logs?

Thanks,

Rob

 

[hammdo]

I have 100 hr for engine and prop (usually at annual) but is possible if one flies over 100 hours a year to have > 1 a year.

 

-Don

 

[Fly Boomer]

1 hour ago, rturbett said:

Is it fair to assume that when you see 100 hour inspections in the logbooks, the plane has been used as a rental?   

 

Anything else that may result in 100hr inspections showing up in the logs?

Thanks,

Rob

 

I have several "100-hour inspections" in my logs that were actually annuals.  Some mechanics apparently use the two terms interchangeably.

[EricJ]

1 hour ago, Fly Boomer said:

I have several "100-hour inspections" in my logs that were actually annuals.  Some mechanics apparently use the two terms interchangeably.

Sometimes it's just that they grabbed the wrong stamp or sticker, but some practice the idea that only airplanes get annual inspections, so only the airframe log shows "annual" and the engine and prop logbooks show "100-hour". 

That said, I think there are some other commercial uses that may require 100-hour inspections, or perhaps if operating under other than Part 91?  

[hammdo]

That’s how’s AP/IA does it…

-Don

 

[rturbett]

Great to know- Thank you!
 

This keeps me from putting a red flag where it is not warranted( without further questions on history)

Rob

[Andy95W]

Technically speaking, only the Airframe gets an Annual inspection.  Other components are inspected as necessary to ensure the Airframe is airworthy with those components installed on it.  For an engine or propeller, that normally entails conducting a 100 hour inspection.

The problem is, not everyone agrees with that rationale.  I’ve redone Annual Inspection sign offs when owners insisted that I’d signed the engine and propeller logbooks incorrectly.  So now, right or wrong, I just sign off everything as an Annual.

I wonder what @N201MKTurbo has heard from his FSDO and what he thinks about it.

[hammdo]

I seen 100 hour/annual combined entry for engine/prop when hours when hours less than 100…

Now I know why…

-Don

[A64Pilot]

I used to do 100 hr inspections just because I could I guess then I got lazy, plus I don’t fly as much now. I did it thinking the buyer one day would take it as a sign that the airplane was well maintained.

If by chance and I can’t imagine this to be a case, but if an IA inadvertently signed off a 100 hour as opposed to an Annual, the airplane isn’t airworthy when it reaches one year from the last Annual sign off, actually the last day of the month the last Annual was done.

I think Mooney rentals are pretty rare?

Anyway only the Airplane actually gets an Annual, not airframe, but airplane, so it’s signed off in the airplane logbook or failing that airplane records I guess.

I know many prop and engine logbooks have Annual inspections signed off, but it’s not actually correct, doesn’t hurt though, mine has Annuals for last decade or so in the prop and engine logbook and I’ve been wondering if I should keep it up knowing it’s incorrect or sign off 100 hour inspections.

To make myself clear, you don’t Annual components individually, you Annual the whole Airplane, the whole thing is in Annual or none of it is.

Some aircraft apparently don’t even have an engine logbook, my 140 for example doesn’t have a prop logbook, never has, but then it’s prop is just one piece of metal.

I guess arguably no logbook is required, you just have to maintain records. Sometime in the past I guess people started keeping separate books for the engine and the prop, but I don’t think it was ever mandated.

[A64Pilot]

22 minutes ago, hammdo said:

I seen 100 hour/annual combined entry for engine/prop when hours when hours less than 100…

Now I know why…

-Don

No, done correctly say if you flew 500 hours this year and had me do an Annual. I sign off 100 hour inspections for the engine and prop.

I suspect it is done that way when separate logbooks for the engine and prop became a thing.

Annuals didn’t become a thing until after IA’s were conceived. Before then your aircraft was inspected every year by a CAA employee and he issued you a new airworthiness certificate.

I don’t remember what year that was, but after WWII I’m pretty sure, article below seems to indicate 1948 if I read it correctly by a DAMI IA’s it seems came into existence in 1956 maybe? And Annuals in 1966 came back, seems there for a few years there weren’t any?

If anyone is curious this article I just found explains it in great detail

https://www.aviationpros.com/aircraft/maintenance-providers/article/11281307/faa-feedback-the-rest-of-the-story

[rturbett]

Great article- 

thank you for sharing!

[Hank]

I have the three original logbooks for my 1970 C--Airframe, Engine and Prop, starting with the test flights and Airworthiness approval. I'll have to check how the engine and prop were signed off at the factory.

[A64Pilot]

4 hours ago, Hank said:

I have the three original logbooks for my 1970 C--Airframe, Engine and Prop, starting with the test flights and Airworthiness approval. I'll have to check how the engine and prop were signed off at the factory.

I did the production test flights for Thrush Aircraft for I’d guess 15 years. Only book I ever signed was the aircraft logbook with the entry of “production test flight completed”

Later after the aircraft was inspected by our DMIR it received its airworthiness certificate, and that was its birth certificate and started the Annual clock. Aircraft that weren’t sold didn’t get the DMIR and Airworthiness cert until they were, so that the buyer had a full 12 months and sometimes it meant the difference between this year or last years model. 

I didn’t look but am pretty sure the engine and prop logbooks just had entries stating they were installed on xxx airframe serial number, I don’t think a 100 was signed off nor an Annual on the aircraft. I don’t think N numbers were used because many were temporary ones as the aircraft were often exported, unsold aircraft flew with our temporary N number 29A, it wasn’t uncommon for two or three aircraft in the factory to have N29A on them., The arrival country’s numbers were not yet assigned, when they were we would put them on the aircraft, there are provisions for that in the FAR’s, but once in a blue moon the receiving Country could get silly, for instance I delivered an Aircraft to the Cayman Islands with their registration numbers on it because it was already registered as a Cayman Island aircraft, but I didn’t have a Cayman license. They ended up issuing me one because me not having one I couldn’t have legally flown it in their airspace