Emergency landing and inversion 13/06/2022

[onetrack]

It can't be too hard to install a mechanical lock to prevent screw-on oil filters from unscrewing. As I understand it, all certified engines have safety-wired, screw-on filter canisters.

Perhaps the problem is, not enough owners approach an oil and filter change with the right attitude. It is a crucial maintenance procedure that must be treated with the maximum consideration as to the risks incurred by playing with the engines lubricating system. 

 

Checking the new filter for transit/manufacturing damage that may cause it to loosen, should be part of the oil change process. Oil filter manufacturing is an automated process, and not every "dodgy" filter is found in the QC process.

Look for dents or buckles. Discard any filter that displays dents or buckles. The oil filter fitment area and surfaces must be thoroughly cleaned and examined for damage.

As Thruster88 points out, filter threads and any filter adaptors must be carefully examined, to ensure all is in order. 

Changes in engineering design can often create problems if there have been changes in threads, dimensions, or part numbers. Ensure you're familiar with all these.

 

The new oil filter gasket must be examined for flaws that may cause leaks or loosening. A coating of new lube oil on the gasket ensures a smooth tightening process - and the oil coating serves as a retention mechanism - as the oil coating on the gasket becomes heated and loses it volatile ingredients, and it thereby becomes stickier, and acts as a filter retention aid.

 

And of course, recommended oil filter tightening procedures must be adhered to religiously. As a general rule, tightening to at least 3/4 turn, after gasket contact, using both hands is recommended.

I would be particularly adverse to using a filter strap wrench for tightening, as strap wrenches invariably buckle the filter canister - and a new, buckled filter canister is a candidate for splitting under pressure.

 

Below is a Avweb article on oil and filter changes for certified aircraft. It contains a lot of very useful advice. Only some of the directions may apply to your aircraft, but all the safety procedures certainly would.

 

https://www.avweb.com/ownership/no-muss-no-fuss-oil-changing/

 

Edited July 16, 2022 by onetrack

[facthunter]

Some of the filters threads are too loose a fit. Reject if they are.. Sometimes the OLD rubber seal will stick to the engine and you get a double seal that is not supported and will blow out under pressure,  Check everything, It's an aeroplane not a lawnmower. Nev

[turboplanner]

The issue is (a) If the design is for the filter to seat as it normally does on the block seal, then the most likely cause is night correctly seating and tightening of the filter.

 

(b) Go back about four posts and there's a photo of a nipple which appears to screw on to the block thread; so the filter if screwed on to the nipple is not going to seat on the block. Just basd on the photo, the filter when screwed on the engine is sitting in mid air so some component is missing, and it may be that this component is unsuitable to the simple screw on attachment method we use for spin in filters, in which case the issue may optentially apply to every engine with a nipple.

[BrendAn]

1 hour ago, onetrack said:

It can't be too hard to install a mechanical lock to prevent screw-on oil filters from unscrewing. As I understand it, all certified engines have safety-wired, screw-on filter canisters.

Perhaps the problem is, not enough owners approach an oil and filter change with the right attitude. It is a crucial maintenance procedure that must be treated with the maximum consideration as to the risks incurred by playing with the engines lubricating system. 

 

Checking the new filter for transit/manufacturing damage that may cause it to loosen, should be part of the oil change process. Oil filter manufacturing is an automated process, and not every "dodgy" filter is found in the QC process.

Look for dents or buckles. Discard any filter that displays dents or buckles. The oil filter fitment area and surfaces must be thoroughly cleaned and examined for damage.

As Thruster88 points out, filter threads and any filter adaptors must be carefully examined, to ensure all is in order. 

Changes in engineering design can often create problems if there have been changes in threads, dimensions, or part numbers. Ensure you're familiar with all these.

 

The new oil filter gasket must be examined for flaws that may cause leaks or loosening. A coating of new lube oil on the gasket ensures a smooth tightening process - and the oil coating serves as a retention mechanism - as the oil coating on the gasket becomes heated and loses it volatile ingredients, and it thereby becomes stickier, and acts as a filter retention aid.

 

And of course, recommended oil filter tightening procedures must be adhered to religiously. As a general rule, tightening to at least 3/4 turn, after gasket contact, using both hands is recommended.

I would be particularly adverse to using a filter strap wrench for tightening, as strap wrenches invariably buckle the filter canister - and a new, buckled filter canister is a candidate for splitting under pressure.

 

Below is a Avweb article on oil and filter changes for certified aircraft. It contains a lot of very useful advice. Only some of the directions may apply to your aircraft, but all the safety procedures certainly would.

 

https://www.avweb.com/ownership/no-muss-no-fuss-oil-changing/

 

I have never buckled a filter tightening it with a cat filter strap and I have done it a lot. Buckled plenty loosening them with a strap. 

[BrendAn]

6 hours ago, turboplanner said:

There is a torquing procedure used on new era engines which is a little bit different, and could possibly be based on manufacturers records that 'x' million filters had never come loose.

 

The procedure specifies a torque value for a fastener (e.g. Head Bolt) then it requires a dial gauge to be fitted and specifies tghtening a specific number of degrees, tensioning the bolt against its thread. These bolts are discarded after one use.

 

Most spin on oil filters now use the same principle, a lot using "smear oil on seal, screw on until seal contact is made, turn filter an additional 3/4 turn.

Yes. That is the method used for Detroit diesels and others for decades.

[BrendAn]

5 hours ago, Thruster88 said:

The only plausible explanation is if the nipple or oil cooler adapter fitting became substantially un screwed when removing the oil filter. I have seen this on a volvo truck engine, fortunately for me the nipple completely un screwed and remained in the old filter.

 

Picture for example only.

That reminded me of one of my trucks a few weeks back. Started leaking and the nipple had come loose. The workshop had to make a special tool to screw it back in

[facthunter]

The length of thread before it goes plain varies on some nipples. It's possible to choose a filter where the thread bottoms before the seal is torqued correctly. If we were 1/2 smart a code would eliminate this possibility. Standard.  Often filters are selected by dimensional reference and not a vehicle specific  listing.. There's risks in doing that.  Nev

[Old Koreelah]

After hand-tightening a new filter I always fitted a hose clamp around the filter body, then lock-wired it to a sump stud. After a well-qualified person called that overkill, I stopped doing it. 

 

Maybe I should go back to my old habit.

 

 

[onetrack]

Every other threaded fastener of importance is either lockwired or secured with some other form of fastening, so why would you leave an important item such as the engine oil filter on a unsecured thread?

[Kyle Communications]

I put a SS clamp..wormdrive one and just wire lock it to a bolt..it cant come off then

 

 

[turboplanner]

A lot of posts relating to a conventional spin on, but did anyone see this photo posted by Thruster with someone holding the nipple and a seal on the block, so two threads and some (missing) component between the block and the filter body to provide a face for the filter seal and TWO threads to come loose?

 

 

Source: Thruster88

[facthunter]

The friction on the largish diameter seal is what holds it there. The specified extra turning decides the pressure on it. Mostly they are harder to undo than the force applied when tightening. There's no harm in a belt and bracers approach but a lose fitting thread and/or a split case will ruin your day.. Nev

[turboplanner]

17 minutes ago, facthunter said:

The friction on the largish diameter seal is what holds it there. The specified extra turning decides the pressure on it. Mostly they are harder to undo than the force applied when tightening. There's no harm in a belt and bracers approach but a lose fitting thread and/or a split case will ruin your day.. Nev

Have a look at the photo in the post directly above yours.

[facthunter]

THAT seal ring should be enclosed so it can't be displaced by oil pressure. That situation is previously covered where the original stays in contact with the block, and you end up with 2 . This is the only failure that ever happened to me. At the factory the original engine is painted black and the filter seal stuck to the undried paint Everything being black it's not noticed so the filter should have been checked. Normally with an aeroplane the filter is cut open and examined for metal particles so that would have been picked up. My normal procedure is to put the old filter in the box the new one came out of.. . Nev

Edited July 17, 2022 by facthunter

[RFguy]

My 912
 

[pmccarthy]

I have seen it argued that the risk of a hose clamp penetrating the filter case is greater than teh risk of theh filter coming loose.

[RFguy]

it is the way it came to me.

those things are hard to get undone at the best of times. notwithstanding the FAILURE MODES of various items as discussed above- threads, the spigot etc etc . 

[facthunter]

I know there have been case failures but I can't recall specific details. Engines can fail for many reasons. A little elbow on the Qantas A 380 lube piping nearly ruined a lot of People's day. Nev

[BrendAn]

last night i watched a you tube about 912 maintenance.  rotaxs method or fitting oil filter is lube the seal as normal. screw filter on until the surfaces mate and then another 270 degrees, which is what turbo described earlier. the rotax guy said if done this way a filter will never come loose.

[BrendAn]

i know we are talking about jabiru but same thing.  and those pistons in the pic i posted are out of the engine that lost the filter.  

[Blueadventures]

BrendAn really need more details like image of the filter attachment area,  what brand filter was fitted, how many hours in service, who fitted it and how; to name a few.

[Thruster88]

I would like to see a pic of the big end bearing, that would be the first thing to fail with no oil pressure. It doesn't appear heat affected in the pic. 

[BrendAn]

i had the pics sent to me , thats all i have. 

as far as i know the motor went to a workshop in s.a and has been scrapped.

i found it odd that the pilot said temp and oil pressure was in the green right up to when it failed.

[BrendAn]

9 minutes ago, Thruster88 said:

I would like to see a pic of the big end bearing, that would be the first thing to fail with no oil pressure. It doesn't appear heat affected in the pic. 

there was still about 500ml of oil in the sump. 

 

[BrendAn]

43 minutes ago, Blueadventures said:

BrendAn really need more details like image of the filter attachment area,  what brand filter was fitted, how many hours in service, who fitted it and how; to name a few.

would help if i could but i only know what i have posted tonight.