New Cylinder AD's released by FAA
 

Well let's see how long this thread lasts. :ugh:

Warning: Disclaimer below needs to be understood
Links below are to another forum.
Links below do have the potential to cause advertising an education source, an Airworthiness Directive, and possibly a parts manufacturer (although it looks like bad press for them).
Links below are to a website run by a not for profit society, but no doubt they do try to run with a surplus to further their cause and pay some employees who run it.
The second link even contains a link to a popular Aviation Web based commercial for profit news outlet.

https://bonanza.org/forums/index.php?topic=101005.0

https://bonanza.org/forums/index.php...253#msg5003253

This could well affect some private TCM powered aircraft owners in Australia.

why don't you post a link to the actual FAA airworthiness directive ?

Coz that is not where I found it nor is there any good detailed story to go with it.

:rolleyes:

Interesting problem. Notwithstanding obvious issues of dissimilar metal expansion rates....why would there be changes in metallurgy of a proven process?...and the robustness of a "screw" fit at the junction of head and barrel...why would this assy separate?

Jaba, are there any further clues? Corrosion? Fretting? Stress risers?

Folks,
I sometimes wonder if this is the FAA acting like CASA.

AOPA USA has done considerable research on this issue for the members, the results were interesting, particularly as (if I am remembering correctly, FAA did not do a cost/benefit analysis) AOPA figures showed the failure rate of OEM cylinders to be worse.

I think there is a definite element of: "I'm from the Government, and I am here to help, whether you want help or not".

Tootle pip!!

This is not new. It is the most recent result of an ongoing issue that's been around for quite a number of years. Some of us who have been following this are a bit surprised it took so long to finalize. The issue was identified almost a decade ago. It's old news.

The screw threads do not hold the head on the cylinder. That is accomplished by an interference fit between the head and the cylinder. That is where the issue has been. If the screw threads were the front line of defense on holding the heads on, all of the heads would be departing the cylinders!

Run that one past again Walter, didn't get a rope on it

This will be interesting!!

This should enlighten a few Pruners. If train wheel outer tyres stay on using this principle so should cylinder heads.

http://www.eci.aero/pdf/SeparationAn...essnaPilot.pdf

Cheers RA

^^^^^^ And before that, many a Wells-Fargo stagecoach completed it's journey on wooden wheels, with shrunk-on steel tyres.!

Wooden barrells also rely on the steel hoops to hold the staves tightly -enough together , that the barrell is fluid-tight.

There's nowt much new in engineering,just the knowledge falls into disuse when an alternative technology becomes more suitable for purpose, for a while.

As an aside, underfloor Central -heating is now the "in" high-efficiency heating-method........WELL! fancy that! the Romans had it a few THOUSAND YEARS AGO.

A great piece of research, nevertheless....about time the US Pilots started a class action against the legislators, for dereliction of duty, unfitness for purpose and Commercial bias against the aftermarket manufacturers.

The latter is irrefutable....they are imposing sanctions against the most reliable products, whilst leaving the statistically least-reliable OEM product untouched.

Dare I ask if $$$$$$$$$ might be changing hands. Calculate what it would be worth to the remaining players if a major competitor was knocked out of the ring. How much were cylinders before a bit of genuine competition came on the scene? Is this what is meant by the current popular term " Government- Business Partnership "
RA

If something stinks, there's usually a reason......something rotten somewhere?

Problem for Australia is that there may be no one with sufficient time, expertise and objectivity in the regulator to properly analyse the data and refuse to adopt this AD verbatim.

As usual, owners will have to pay to address a remote risk that is patently clearly not of their making and, more bizarrely, is patently clearly a more remote risk than the failure of the OEM’s product. All in the name of ‘safety’. :yuk:

Something rotten..... In Denmark?
Cracks at to the screw thread are not new as Walter has said.
How many cylinders in Aust are affected?

If the AD comes out it is auto on our system. Yes oem cly cracked but let's compare apples to apples. Ie hours to hours. The older the cly the more likely it is to crack. So are these 1st service life cly that are failing or second or 3 rd time around the block. If they are 1st then not hard to see why the looking at them careful. Funny that is why we do a leak rate check one of the things we also look for but some think a leak rate is not relevant
Cheers

CASA has discretion:

Casa won't go against another country's AD. They will not do it for litagation
Cheers

Sadly, I think you are correct. The GA sector in Australia doesn’t have sufficiently united brains or brawn to make CASA exercise its powers on the basis of objective data.

(PS: Great to see the incredible improvement in your usage of apostrophes, yr right. ;) )

Creampuff,
You may remember the Bell47 Main Rotor grips that were downgraded to 1200 hour life. In Australia we convinced CASA that an eddy current inspection of the threads allowed us to retain the original hour timex.
So it has been done before

Creamie,
Too true.
The last engineer (as opposed to LAME) who had serious knowledge and experience with piston engines retired quite some time ago.
The AOPA US developed failure statistics showed the illogical position of the FAA clearly, why a proper cost/benefit analysis was bypassed has never been explained.
Sadly, high level administration of the FAA is seeing fever and fever people of serious aviation expertise, and more and more "career" public servants.
Tootle pip!!

Yes, but how many decades ago?

There is no doubt it could be done again, but it would require a level of unanimity and commitment that, sadly, I think no longer exist in GA in Australia. :(

They used to look at all ADs and make there own judgement now they don't and we lost a great deal of good ones when they started that allowed everyone to know where they should. Now it's just a mess a system that is useless and still not common to anything or any where. It's a disgrace.
Cheers

Compliance with Airworthiness DIRECTIVE of the NAA of the OEM or TC or STC holder is a requirement of Australian regs. CASA promulgates the foreign ADs in Part 39. Note they are no longer issued as Aust ADs.
Indeed Creampuff, time passes in the blink of an eye, was in the 1990s

Did you mean ‘Airworthiness Directive’ rather than ‘Airworthiness Data’?

If you meant ‘Airworthiness Data’, what is your definition of that term?

Creampuff
Airworthiness Directive is what I meant
At the risk of thread drift and tailwheel taking us all out the back of the hangar for a damn good flogging I am willing to discuss the differences. Remember though I am just a dumbass mechanic from Tennant Creek who failed matriculation

In that case, you are correct: There is an automatic obligation to comply with what the CASRs call a ‘foreign State of Design airworthiness directive’ (as well as comply with an ‘Australian airworthiness directive’). That’s because CASR 39.002 imposes an obligation to comply ‘airworthiness directives’, and the definition of ‘airworthiness directive’ in CASR 39.001A covers both ‘Australian airworthiness directives’ and ‘foreign State of Design airworthiness directives’.

I merely reiterate that CASA has the discretion to approve a means of compliance with an AD other than that set out in the AD, and CASA has the discretion to exclude a particular kind of aircraft or aeronautical product from the operation of an AD: see CASRs 39.004(2) and 39.004(3).

Read all about it here: Civil Aviation Safety Regulations 1998

The approved maintenance data for an aircraft and the maintenance schedule applicable an aircraft are related but different regulatory concepts. Read all about them here: Civil Aviation Regulations 1988

And BTW: I too am just a dumbass who left school at 15 to start an apprenticeship. :ok:

Creamie,
Such excessive modesty !!:)
Tootle pip!!

No Hoper and Leaddie: Check your PMs!

What amazes me is at what cost do you put on safety. You seam more worried that FAA is using it powers for evil. I would think that the cost should not be brought into it. I known the FAA dose costing and have done for a long time which is a lot different to what we have here.
Dick smith had a affordable safety. I know how dangerous that was when a pilot that was normally bright and bubbly was as white as a ghost. He nearly had a mid air late at night. When I ask how close was it he pointed to the top of the hangar wall. Luck was riding with that night as we'll as the crew down the back.

So at what point dose it stop. I think this is a very basic AD. Not much to it. As I've said earlier at what point have they being failing. If first life I can see why. I never seen or heard of an OEM cly failing at a 1st life.

What amazes me are the idiotic decisions that are made in the name of safety. When a decision is made that can't be backed by data the powers that be bellow "SAFETY" to shut down any further discussion. Those who think there is no such thing as affordable safety have a very poor understanding of risk management.
If "affordable safety" is abandoned it follows that even a cessna 150 should be fitted with a zero zero ejection system and that Malaysian Jet should have had personal ejection seats for every passenger + a life raft equipped with VHF and HF radios and 2 weeks of food. If you think this is nonsense then you actually do believe in affordable safety and the discussion then becomes where to draw the line.
Cheers RA

Rutan
That is what is called an Absolute
Have been considering Walter's bait
Without the screw thread the head would depart on the first runup
It is a combination of the screw thread and interference fit that retains and locks the head to the cylinder

No Hoper
Do you have Data that shows this to be true? I always thought the above to be true. In fact I didn't even know there was a shrink fit involved.:{
Having now read Mike Busch's article (Link post 10 ) I tend to believe a cylinder manufacturer probably knows more about how they work than I do. I do know that train wheels seldom fall off and they don't have a threaded section to help hold them on.

I agree with Rutan: It’s amazing how the word ‘safety’ can turn some people into gibbering idiots.

I’ve posted this in the threads about DAMP and the proposed SS terminal AD, but it’s about this ECi Cylinder AD. Well known expert and aviation journalist Mike Busch said this, in part, in response to the NPRM for the AD:My all-time favourite comment on this proposed AD (and any other one for that matter) is:You see, yr right, if the probabilities and consequences of ECi cylinder failures justify this AD, it follows that other risks with similar probabilities and similar consequences must justify similar regulatory action.

For example, people with learning difficulties should be prohibited from conducting maintenance on aircraft. Even though there may have been zero accidents and zero injuries from their activities, they could cause a big accident by misunderstanding some important maintenance data. All in the interests of ‘safety’, old boy. Surely it’s a cost you’d be willing to pay? I’d be amazed if you disagreed.Is that your guess, No Hoper, or a conclusion supported by data?

Seems basic engineering
A screw thread retains and then it is locked if in a high load situation.
Lock nuts come to mind, wouldn't work without the screw thread
Although in the olden days was split pinned or wire locked.
One can also wire lock the bolt heads in a blind bolt situation

My guess is you are correct. However, I don’t have any data to back that up and, like many things in life, the correct answer could be counter-intuitive.

I’m hoping Walter A or John D will enlighten us with the results of their research. :ok:

Well everyone has leaning problems for a start. You may be an academic but can you true a screw driver generally no. I know off a very clever fella that once fixed his 210 in to a 182 buy glueing his u/c handle into the down position or one friend that I will assure you all that make you like a primary school kids but put a nut on and his lost.
Where is the data that these are failing at are they 1st life, like ive said cly failure on general don't happen on a 1 st life engine OEM and separation happens at the end of the screw thread.
Now this also proves that it is a between the inter fit and the screw thread that hold the head on. With out either that don't stay on. Manufacture's wont do unnecessary work like fit a screw thread for know other reason. Also there is nearly always a sign before separation, you need to know the signs.
Why did we never use R1340 engines cause when they have a head separation the engine stops and in a R985 the engine looses performance and allows you to get back. We never had a head separation because we always always always checked during the day on shut down and ever night on return to base.


So why do you think that FAA wont these cly out of service.


And why don't I have a problem because I check recheck and check again that's why im good at my job. That's why im get ask all the time what im doing , that's why im sent all over the place to work.


Cheers

That’s what most of the world’s experts are wondering.Something stinks… to high heaven.But going on the logic that has resulted in this AD, your zero accident and zero injury history is not enough. You have a known problem that could cause accidents and injuries in the future. You must be stopped, in the interests of 'safety'.

And BTW: I reckon you work for CASA. ;)

Me casa I think not. My family would disown me if I went to the dark side. Soypu also should be stopped as your own disability is far worse than mine.

So once again go f yourself. I deal in common sence you still not said when these cly are failing

Yep: You and me both should be stopped in the interests of ‘safety’.

You and I know why the cylinders are failing: Excessive leaning. ;)

Pilots of aircraft with engines fitted with ECi cylinders run them excessively lean. When one of those cylinders fail, the pilots do a forced landing and sneak over to another aircraft with engines fitted with stock CMI cylinders and sledge hammer the heads off two cylinders. Thus the logical regulatory response is to mandate replacement of ECi cylinders. It all makes perfect sense ...

... on the Planet Coosbane. :ok: