I don’t think a “reasoned argument” is necessary, or any argument.
Is there e.g. any defined life for a vacuum system inlet air filter in any case, for most planes, other than replace based on condition?
My maintenance schedule says there is……hence my statement about smoking.
@PeteD, do you mean the vacuum system
inlet air filter replacement interval is dictated within the limitations section of the maintenance manual?
If it’s an FAA certified light aircraft type, the design intent was operation within Part 91, which applies a practice of maintenance on condition, except as limited in the MM. I’m aware that individual EU and UK register aircraft have a different individual maintenance plan, but that is arbitrary data made up by local mechanics that isn’t binding to the type as a whole.
Yes, Inlet filter ever 400hrs, Vac relief every 100hrs/Annual per Grumman Tiger, AG-5B maintenance manual.
I’m on the M(manx reg) and you have to state the Maint. Schedule that you intend to use.
I have a choice of manufacturer’s schedule, FAA, EASA etc, provided it is acceptable to the registry. The “correct” answer is usually the manufacturer’s, which is what I use.
I’ve heard the Manx register maintenance requirements are a bit of a mess, but did not understand that detail.
Under FAA Part 91, which is what your Tiger was designed to be operated under for private use, the maintenance manual (MM) as a whole is not binding on the owner or mechanic. What is binding, as per the intent of the certifying body (FAA) is the limitations section (only) of the MM. That distinction is why the Limitations Section exists. Some registries carry forward this proper application of the certifying body’s intent, some do not.
The fact that you and your plane individually are constrained by arbitrary local authority to operate rigidly under a MM that was (other than the Limitations Section specifically intended for that purpose) actually designed as guidance for the mechanic, does not imply that a “reasoned argument” or any argument should be necessary or required to operate according to FAA Part 91 and replace the vacuum system air inlet filter based on condition.
What’s more interesting to most owners that aren’t so constrained by local law is when an accessory filter is used under an STC that is separate than the aircraft TC, and that STC sneaks in a mandatory periodic replacement schedule. As I mentioned above, Brackett engine air filters have this constraint and many people are completely unaware of it.
To be honest, the cost of a vac filter is minimal.
I certainly find the M reg very good, being able to choose your schedule, so I disagree that “maint. requirements are a bit of a mess”.
You just make you choice…..and can do quite advantageously.
and can do quite advantageously
M-reg is not available to the vast majority of “GA”. For below a few tons you have to live there (there used to be workarounds but no more). I had an interesting meeting with their Director of aviation but that was a few years ago (he didn’t like Part 91 at all, but on the planes they do accept not many do that anyway).
Maybe, detail would be helpful to some. Long thread on these registries. But few people give detail, maybe because they aren’t closely involved in bizjet/TP maintenance.
Anyway, this is what I had in mind. This filter has done about 150hrs airborne; in fact maybe 300. Spotless:
On N-reg, everything can be “on condition” unless there are specific rules in the right part of the MM, or in the ICA section of an STC/FA/etc which was used to install something.
Silvaire wrote:
I’m aware that individual EU and UK register aircraft have a different individual maintenance plan, but that is arbitrary data made up by local mechanics that isn’t binding to the type as a whole.
Only for Annex 1 aircraft. Non-commercially operated EASA aircraft can be maintained just like an N-reg.
Non-commercially operated EASA aircraft can be maintained just like an N-reg.
In theory, in theory 
We’ve been here before, lots…
