I would say YES, but I am not an NAA. Especially not yours. ;)
But the rule sort of supports this as well since it says:
— maintenance recommendations, such as time between overhaul (TBO) intervals,
issued through service bulletins, service letters, and other non-mandatory service
information
I would guess that the TBR is a maintenance recommendation, “such as TBO”.
TBR means it is a “lifed” item.
So IMHO this depends on the treatment of lifed items.
On Part 91 lifed items are not permitted to be enforced unless in the Airworthiness Limitations Chapter of the MM (this is to prevent revenue generation schemes by manufacturers).
OTOH, mechanically speaking, it depends on what is actually wearing out. Pretty obviously you can’t detect everything by cylinder compression, plus checking the filter(s) for debris.
Then the argument is whether anything inside matters if the engine is ok on compression and is not making metal, and this is what most people think when it comes to the traditional engines, and probably correctly up to maybe 3000hrs. The wear patterns in these engines are extremely well known.
But the diesels may have entirely different wear patterns. There may be parts which work fine until they wear enough to just break.
I expect the manufacturer knows this but is not likely to release the info openly because TBR=€€€.
Thr term “lifed” does not exist in aircraft maintenance manuals. It’s also very ambiguous. I don’t know why it keeps coming up, from UK posters only AFAICS. As long as that is term is used, misunderstandings will continue.
An item has either
And then, there is what the various CAAs make out of it, which is where it gets complicated.
The term “lifed” is an English expression (hence UK posters use it 
) for life-limited items i.e. items which the manufacturer would like you to chuck away at a specified point, regardless of condition.
Whether it is actually required to be chucked away in order to preserve airworthiness depends on the regulatory regime.
Talking about TBR of Diesels, many of you will already have read this:
http://www.avweb.com/avwebflash/news/Continental-Extends-Diesel-TBRs-226092-1.html
So if my body reaches TBR, my engines may still be purring along nicely 
Of course Conti is clever enough to apply this only to new engines. But unless they can demonstrate that these engines have undergone a design modification I don’t see why I could not also make use of this extended TBR with my existing engines. Although there is also a 12-year calendar time limit, which is not mentioned here..
aart wrote:
But unless they can demonstrate that these engines have undergone a design modification
At Aero they said they modified the crankcase for that.
Mooney_Driver wrote:
Page 30:AMC
ML.A.403
Aircraft defects
Aircraft equipment should be declared as defective if the re is a significant risk that it will fail to perform the functions required at a level of performance consistent with the acceptable level of safety of the operationSo do I have now to perform a risk analysis on each component of my plane before each flight?
Since I drafted that, I’ll risk a comment. Under the current Part-M, all “defects” must be checked out by an engineer. Under the proposed Part-ML, while some pilot deferal of defects is permitted, “defects” in required equipment still cannot be deferred by the pilot. But what is a “defect”?
The dictionary definition of defect is “a shortcoming, imperfection, or lack”. There are many observed imperfections with aircraft and their instrumentation that are worth writing down, particularly with shared aircraft. Better communication of this sort generally improves safety. But if a “defect” is interpreted as any imperfection, we can be pretty confident that no observed imperfection will ever be written down, unless the equipment is obviously still broken.
So the full text (as Fly310 pointed out) is:
AMC ML.A.403 Aircraft defects
Aircraft equipment should be declared as defective if there is a significant risk that it will fail to perform
the functions required at a level of performance consistent with the acceptable level of safety of the
operation. This does not prevent the pilot from recording observations and comments on the
performance of the aircraft equipment where this is not considered to constitute a defect.
That is intended to mean that you can write down “AH slow to erect”, “engine running a bit rougher than normal on R mag” or “heater doesn’t” after your flight, to warn the next pilot without necessarily taking out of their hands the decision as to whether the aircraft is airworthy or not.
I can imagine aircraft owners being instructed to review their own maintenance ‘declarations’ as part of the properly structured approach to aircraft ownership… perhaps doing so every Wednesday evening I think you can be 100% certain that in the case of an aircraft owned and flown by one person, he’ll make no official written record merely to declare a defect in his property prior to arranging repairs.
A tiresomely prescriptive regulatory approach is really not appropriate for maintenance of private property, and I think in that context it reads a bit like comedy.
bookworm wrote:
So do I have now to perform a risk analysis on each component of my plane before each flight?
And… I would say, yes. Otherwise known as common sense. “AH slow to erect”. Ok, that thing isn’t up to snuff. Day VFR – couldn’t care less. Hard-core IFR at night with weather at minimum, limited alternate, and with known dodgy AI – well, you decide.
bookworm wrote:
That is intended to mean that you can write down “AH slow to erect”, “engine running a bit rougher than normal on R mag” or “heater doesn’t” after your flight, to warn the next pilot without necessarily taking out of their hands the decision as to whether the aircraft is airworthy or not.
Interesting. So you mean that under the current rules, every written observation that a mandatory piece of equipment is not performing 100% to expectations means that the aircraft is no longer airworthy? In that case I would except everyone to operate illegally.
