Difference between 100 hour and Annual inspection

[Sam Rutherford]

My 'new' mechanic is telling me that instead of a 100 hour inspection, I should do an annual - 'the work's pretty much the same'.

I don't think it is, and given that my airplane has had 2 annuals in the last 6 months I'm keen to avoid unnecessary cost in this area!

Thoughts?

On the same subject, as a private user do I have to do the 50 and 100 hour servicings, or is it just the Annual that is legally required? I plan on doing all of them out of simple good sense, but would like to be sure of the legality of things.

Thanks, Sam.

[210TC]

Sam,
It is best you pull out the rule book and read it yourself. You appear to be a commercial operator ( hear in the US we only do 100 inspections for commercial ops). If someone gave you the wrong info you could suffer more than you could afford.
It really does not take long to read on this subject and you will learn that many things people have told you in the past "don't fly"

[UP-M5]

the following applies to US FAR's only, i am not familiar with the european regs......

an aircraft operated part 91 is only required to have annual inspections- UNLESS it is being used for flight instruction. which would make 100 hr inspections necessary also. a part 135 aircraft is required to have 100 hour inspections, and any other maintenance called out for in the operators ops specs (which may include 50 hr or progressive inspections) the part 135 aircraft must also have an annual inspection.
the scope and detail of 100 hr and annual inspections is the same. they are the same inspection. only that an IA must perform the annual, and an A&P is allowed to sign off the 100 hr.
my opinion is that any aircraft flown regularly enough to accumulate over 100 hrs per year, should have 100 hr inspections- for safety sake. and these inspections could be signed off as annuals if need be.
for instance if a part 91 aircraft flies 125 hours per year, i would want to do an inspection at 100 hours, and sign it off as the annual. but if the same aircraft regularly flies 350 hours per year, you could do 2 100 hrs and make the next one an annual.

anyhow, a 100 hr and an annual should cost the same. if not- you are not getting a thorough 100 hr inspection.

[aero101]

Ditto- My aircraft is used commercially, I do the 100hr inspections, and I'm also an IA, so every 100hr I do I sign off as an annual as they are both the same scope and detail of inspection. The main advantage being that if I ever quit using aircraft commercially or decided I wanted to sell it, it would have a fairly recent annual... If you're not using the aircraft commercially, there is no requirement for the 100hr inspection and depending upon the usage, I think that you could probably lighten up on the scope of the inspection, but that's all a matter of personal preference. Most people I know that aren't commercial operators, flying those kind of hours, usually incorporate the 100 hrs into a progressive inspection by breaking it up and doing parts of it at each oil change at 25 hr intervals, then just doing the annual as required. This way you break up the big expense all at once, as well as reduce the down time to smaller time frames.... It's all a matter of preference though.

[a64pilot]

Is your aircraft an "N" numbered aircraft being maintained by a US certified A&P/IA?

[Speedy]

Hi,

I have a related question, especially to the IA's in the forum. My IA (US certified working on US-registered aircraft under FAA-Regulations) only signs off the aircraft logbook as an annual inspection. The engine and prop logs he signs off as 100-hrs inspections, saying (1) the annual of the aircraft "covers" the components and (2) the components can't have annual inspections.
Older entries in the prop and engine log consistently show annual inspections.

Who is "wrong", the IA's who certified annuals on the engine and prop in the past in the engine/prop log or my IA?
Greetings,
Speedy

[Sam Rutherford]

In answer to A64, my plane is still N reg, so everything is done FAA.

This does make things a little complicated on this side of the pond as even the FAA certified guys are not as 'current' as those in the US.

For Speedy, my engine and prop logs also show annual certification...

Sam.

[a64pilot]

Speedy,
Your new IA is correct, although a lot of IA's sign component annuals off. Actually only the aircraft requires an annual.

Sam,
Your new IA is correct, and is looking out for you.

[aero101]

Reference AC43-9C -
"d.; Questions continue regarding multiple entries for 100-hour/annual inspections. As discussed in paragraph 5c, neither part 43 nor part 91 requires separate records to be kept. Section 43.11, however, requires persons approving or disapproving equipment for return to service, after any required inspection, to make an entry in the record of that equipment.
Therefore. when an owner maintains a single record, the entry of the 100-hour or annual inspection is made in that record. If the owner maintains separate records for the airframe, pow&plants, and propellers, the entry for the 100-hour inspection is entered in each, while the annual inspection is only required to be entered into the airframe record."

[Speedy]

Reference AC43-9C -

Thank you!
Speedy

[aero101]

Speedy-
I will agree with your IA that signing off the airframe log is legal, but I will dissagree that you can't annual a component... For example, if you remove an engine to 'BORROW' and install on another aircraft and that engine has a current annual signoff, that engine can fly on that aircraft with no further inspections required as the annual signifies that it was inspected by an IA and that all AD's were complied with on the engine until the end of the 12th month after inspection. (The engine logbook stays with the engine, in this case on another aircraft that you need to document eng change on. You will need either a yellow tag or a current annual inspection for this engine to be airworthy.) A 100hr inspection does not require an IA signoff, nor does it require the routine AD search that an annual inspection does. Same thing with a propeller or any other component part robbed from one airplane to another. So it's kind of a catch 22 which may or may not happen in your lifetime so long as all the components stay on the original aircraft, but these situations do occasionally happen and even though I'm not required, I do sign off engine and prop as an Annual Inspection as it can prevent confusion in the future...