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A good video on risks of cylinder replacement

here

Unfortunately Mike Busch talks incredibly slowly but a good bit is around 25 mins into the video, and there are really good bits after that on how much bolt preload is affected by the lubrication of the threads, and by the way the torque wrench is operated. Get this wrong and you will have under-spec preload, with loads of problems.

What is really interesting is that when you change more than one cylinder, you have to tighten up all the other through-bolts to prevent the bearings rotating while the engine is worked on. This sort of thing helps explain why so many engine shops manage to screw up.

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

This sort of thing helps explain why so many engine shops manage to screw up.

IMHO, there is NO excuse for NOT following the Service Bulletins and Maintenance Manuals that outline this very important & critical procedure.

FAA A&P/IA
LFPN

Peter, finally I find an hour to listen to this and find that almost all that is said on the presentation is what we do, what I did not apriciate was the effect that lubrication had on the preload, as we have always provided ample lubrication of the threads this was interesting rather than a game changer for us.

I do think that fitting of torque plates is critical, it is my opinion that these also stop oil getting in between the bearing saddles and effecting the preload when the cylinder is re-fitted.

That video could cut to 3 minutes with the very same information… especially as it boils down to “do it as the manufacturer recommends”.

You could say the same for all of Mike Busch’s videos He could do with an editor…

Administrator
Shoreham EGKA, United Kingdom

There is a big discussion about this whole thing in Switzerland right now.

Following a crash of a badly maintained Saratoga a few years back, Switzerland has basically banned “on condition” operation for GA engines and allows exceptions only under the pretext that in regular intervalls invasive maintenance involving pulling at least two cylinders has to be performed to assess the interior of the engine.

There has been a huge outcry in Switzerland over this, as many people saw themselfs grounded without any warning and at the same time had to perform maintenance they regarded unsafe.

Now, it appears that this practice has cost the life of a Glasair owner and got one innocent bystander severely injured. Last week, a Glasair equipped with a IO360 suffered a severe engine fire in flight. The pilot, who was the owner and builder and who had extensive experience with the airplane and was known for his immaculate maintenance of this 20 year old airplane, managed to land the aircraft but suffered 80% burns of which he died after having been rescued out of the burning wreck by two courageous bystanders.

It has since become known in the circles around him that it was only a few weeks ago when this engine had to be torn apart to comply with the FOCA directive as it was older than 12 years. There is a very high probability that the “safety measure” imposed by the FOCA is to blame for this in combination with some maintenance error while performing the unnecessary task.

The accident and it’s implications are very seriously watched by the Swiss aviation community. Since the new rules were enforced, quite a lot of people think of outflagging their airplanes rather than submit to this senseless risk. If it proves to be true that this engine failed because of this, I hope there will be sufficient political pressure to bring this thing down and to get the FOCA to adhere to EASA ELA1.

LSZH(work) LSZF (GA base), Switzerland

The problem is that how do you deal with muppets doing the work?

You could say that an aircraft should not be lubricated – because some muppet might use WD40.

I know a lot of people can’t read a maintenance manual (well, a lot of people these days won’t read past first 5 lines of an email, so what chance is there of them reading the 150 page IO540 MM, where the torque settings are at the very end) but one has to draw the line somewhere.

I am not advocating pulling cylinders at 2000hrs on a healthy engine, but there are limits…

The adult illiteracy issue is just as big in the USA as in Europe but the USA has the advantage of many more experienced shops, and more inter-pilot communication as to where to go or not, whereas over here people tend to keep quiet.

Administrator
Shoreham EGKA, United Kingdom

Peter,

knowing about this pilot, who had a 40 years experience of flying as well as aerobatic license as well as having built this plane and flown it for a long time, he certainly did not let anyone near this plane who was not competent. Apart,the engine did not have near enough 2000 hrs but was simply out of calender TBO of 12 years! The new ruling sais that if you want to run on condition, every 3 years after TBO you have to pull 2 cylinders on a perfectly healthy engine to inspect the interior of the engine.

There is NO sane reason to do this. None. And ANY form of invasive maintenance brings a risk of actually damaging the engine rather than fix what ain’t broke.

I understand that Mike Bush has been involved in the opposition to this new rule ever since it was started past June or at least his publications have been used as arguments. We will have to wait and see what happens, but there is a huge outcry over this here and I do hope that legal steps taken at this moment will at least stop this nonsense before more people get killed.

LSZH(work) LSZF (GA base), Switzerland

he certainly did not let anyone near this plane who was not competent

I’d like to think that description would apply to me also, and I have p1ssed off enough people in the business to earn it But I still got this Grade A bodge job, and got a frozen elevator trim, and other stuff…

The reality is that most owners don’t have so many options, have to make a hard decision between using a based company, and flying somewhere (with all the hassle of getting back etc), and there are so many ways to screw up.

Also a lot of people are in syndicates where you often get a member who has an overpowering personality and who dictates how things should be done, and you have to decide how much it is worth to you to tackle him.

Administrator
Shoreham EGKA, United Kingdom

I never understood swiss GA. Being under swiss register seems to be a nightmare in many ways (at least compared to N-reg or say D-reg). Still, most GA aircraft in Switzerland are HB-reg. and very few are N-reg or other European regs. Is there some tax reason that most swiss people keep most of them HB-reg? Or is it just some national pride/loyalty thing? Or just that the swiss are generally very “conforming” people?

Last Edited by boscomantico at 24 Sep 15:50
Mainz (EDFZ) & Egelsbach (EDFE), Germany
33 Posts
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