Pour les moteurs : 360’s, 470’s, 520’s & 550’s, construit, remis à neuf et/ou réparer impliquant un ‘’Vilebrequin (Crankshaft)’’, entre le 1 juin, 2021 et le 7 février, 2023!
Voici un ‘’Article en anglais’’ d’Information préliminaire!
Continental Calls for O-360, O-470, O-520 and O-550 Engine Counterweight Inspection!
By Paul Bertorelli, - Published: February 10, 2023Updated: February 11, 2023
Continental Aerospace Friday said it’s asking owners of O-360, O-470, O-520 and O-550 series engines manufactured after June 1, 2021, and with fewer than 200 hours to perform crankshaft inspections to check counterweight retaining ring installations. The announcement from Continental follows a report from Cirrus on Wednesday that it has grounded all of its own aircraft in response to an alert from Continental about a potential engine manufacturing defect.
Here’s the full statement from Continental: “Continental has identified a potential safety of flight issue for aircraft equipped with Continental 360, 470, 520, 550 series engines and replacement crankshaft assemblies. Consequently, Continental is preemptively advising that an inspection should be performed to confirm that the crankshaft counterweight retaining ring was properly installed in new and rebuilt engines assembled between June 1, 2021, and February 7, 2023.
“This advice also applies to replacement crankshaft assemblies manufactured between June 1, 2021, through February 7, 2023. Continental proactively recommends that all flights powered by the aforementioned engines with less than 200 operating hours be limited to 5 additional flight hours with the essential crew to position the aircraft at a maintenance facility. To further clarify, Continental engines with over 200 hours may continue normal flight operations. A service bulletin with affected serial numbers will be forthcoming.”
The total number of engines affected is unknown, but Continental said Friday that more information would be forthcoming, as will a bulletin describing the inspection procedure. Warranty performance and reimbursement will also be detailed. On many of its engines, Continental uses moving counterweights to reduce torsional loads on the crankshaft. The weights are held in place on the crankshaft with a pin arrangement secured with snap rings. The weights counteract torsional loads by sliding across a small range of movement. The defect appears to be that the snap rings were installed reversed. This could mean the open end of the ring is facing outward, rather than toward the crankshaft centerline. The weights and snap rings can be accessed by removing cylinders without the need to split the engine case or remove the engine from the airframe, according to previous Continental service bulletins. All of the engines in question are six-cylinder models.
Paul Bertorelli,
Jethro B. February 10, 2023 At 5:05 pm
The article seems contradictory. In one instance it says that Continental is “requiring” owners to perform inspections and in another it says that Continental is “advising” owners that inspections be performed.
I suspect the latter is correct. Continental has no authority to “require” that an owner perform an inspection.
Matt W. February 10, 2023 At 7:14 pm
I said this when Mr. Niles first wrote about this and I’ll say it again. Since cylinders have to be pulled to access the counterweights, is Continental creating a solution that may be worse than the original issue? Is this solution a cheap way for Continental to get out of replacing engines outright? I wonder who gets to pay for all those inspections?
. February 12, 2023 At 7:22 pm
I guess being owned by the Chinese government makes you forget how to assemble components after 60+ years of doing it.
Lewis M. February 13, 2023 At 8:41 am
Holly Molly! Continental… Well, now “we know” what the “issue” was when Cirrus announced some of its fleet be grounded because of an “issue”. Continental should be responsible for replacing the engines. If I had a brand new Cirrus in this circumstance I would not accept “removing the cylinders” to inspect the snap rings! Screw that! It’s not my responsibility to cheaply try to fix a problem created by Continental. Replace the engines Continental! You caused the problem on your factories! Brand new engines! That’s it.
George H. February 13, 2023 At 12:32 pm
WE will ALL pay for Continentals’ mistake…. via increased costs so Continental can recover the expenses from this screw up. :{
(This is not likely due to Chinese ownership, however. It’d likely due to an inexperienced employee new on the task.)
Roger a. February 13, 2023 At 8:43 am
Not being a mechanic, what does the direction the snap ring faces make and what happens that makes it ok after 200 hours. Anybody know? Inquiring minds….
Papua P. February 13, 2023 At 11:40 am
Snap rings are stamped when they are made. The top side is slightly rounded and the bottom side has a sharper edge. When you install it, you want the sharper edge facing out, this aids in holding it in place. Having the rounded edge up can lead to the snap ring coming out, which is most likely the problem that has happened here.
George H. February 13, 2023 At 12:34 pm
Papua, that’s not the problem in this case. It’s that open-end of the snap-ring facing outboard instead of inboard….which may place unexpected stresses on its’ retention.
Ronnie S. February 13, 2023 At 10:03 am
This is gonna be ugly no matter what. There are now 2 separate issues with the same engines during the same time frame of manufacture. AD 2023-02-12 covers Superior cylinder valve issues and now this counterweight issue on the same. Thats gonna be the kind of warranty work no one wants.
J’espères que cela ne s’applique pas à vous!
Jacques
Inspection requise sur les Moteurs Continental, six cylindre
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Re: Inspection requise sur les Moteurs Continental, six cyli
Continental Issues Counterweight Inspection Bulletin
By Paul Bertorelli, Published:February 13, 2023
Continental Aerospace Technologies Monday released a mandatory service bulletin describing how to inspect for improperly installed snap rings on about 2000 six-cylinder engines. The bulletin describes how to reseat the rings, if necessary, and also details warranty reimbursement.
The issue surfaced earlier this month when Continental notified Cirrus through a letter that snap rings had been improperly installed on engines and crankshafts manufactured between June 21, 2021, and Feb. 7, 2023. Continental said Monday that the problem was caused by improper assembly, not a defective part.
On its six-cylinder engines, Continental uses crankshaft counterbalance weights that move and suppress torsional or twisting loads on the crankshaft. The weights slide across a small range of motion and are able to respond to RPM shifts. They ride on pins held in place by the snap rings. The company says the snap rings were improperly installed and may not have seated fully in the groove designed to retain them.
The service bulletin requires inspecting the snap rings by removing one to three cylinders—variable with engine model—to gain access to the weights. The weights themselves do not have to be removed unless difficulties are encountered in seating the snap rings. Continental will loan a gauge to insert between the ears of the snap rings to determine if they’re fully seated. It also provides dimensions to field manufacture the gauge. The gap should be between 0.179 inch and 0.212 inch, depending on the engine model. The service bulletin describes how to reseat the rings if they are out of spec. The bulletin also advises techs to make sure the open end of the snap ring is oriented toward the crankshaft centerline.
Engines with more than 200 hours are exempt from the inspection, the reasoning being that if the rings allowed the pins and weight to depart, that would have occurred in the first 200 hours. It’s not known how many of the listed engines have accumulated this much flight time.
Continental will cover the cost of the work under warranty, for both engines and crankshafts. It will also establish a direct dial call center at 251-441-4460 for questions on the procedure.
Paul Bertorelli,
William . February 13, 2023 At 5:02 pm
Lousy situation but I respect them for taking responsibility and trying to make it right.
The obvious problem is that pulling cylinders will affect preload on the main bearings and this can lead to issues in the future, that will not likely be covered by warrantee.
Black B. February 14, 2023 At 1:02 pm
Preload on the mains? Detailed explanation needed please.
Never heard if it.
Paul B. February 15, 2023 At 7:49 am
A horizontally opposed aircraft engine is a light structure that carries a lot of load. It’s critical that the through studs holding the case together are torqued to the right value in the right order.
When cylinders are removed, if not done correctly, it can distort the torque loads on the case and thus the main bearings. This can cause them to spin in their mounts and fail. While this is not a common cause of engine failures, it happens frequently enough after cylinder work to raise real alarm about removing three cylinders from one side or even one cylinder.
Torque plates to hold the load temporarily are supposed to prevent this, but believe it or not, not all shops know how to do this properly. If it were my engine, I’d take it to a good engine shop where they’re more likely to know how to do it correctly.
Bob G. February 14, 2023 At 4:50 am
I had to look-up what a snap ring was – we call them circlips here in the UK.
Richard P. February 15, 2023 At 8:18 am
In the USA, we generally use “circlip” for the plain wire variety, often used to locate wrist [gudgeon] pins in the piston.
Joe P. February 14, 2023 At 8:28 am
“Continental said Monday that the problem was caused by improper assembly, not a defective part.: The kinda have to cover this. Improper assembly is never a good thing.
Ronnie S. February 14, 2023 At 10:11 am
I want to see what Continental and Cirrus call out for the acceptable time to perform this inspection. Usually they are way off and whats the shop rate they are figuring it on.
Rush S. February 14, 2023 At 11:49 am
Click on the “service bulletin” link for specifics. Replacement crankshaft assemblies allow for 0.15 hr inspection time, and 0.25 hr for replacement or adjustment (per counterweight).
For engines, add 10, 18, or 22 hours for cylinder removal, depending on whether the specific model requires pulling 1, 2, or 3 jugs.
Richard H. February 14, 2023 At 6:33 pm
Can’t believe those time estimates.
Richard P. February 15, 2023 At 8:18 am
Yeah, I think in 22 hours I can build an engine from the parts bin, and install it.
Cockpit p. February 14, 2023 At 11:49 am
Bad deal for new engine owners. You paid for a new engine, now have your local A&P tear it apart. Good luck.
Eric . February 14, 2023 At 12:34 pm
How many engines have had the pins and weights come apart?
How was this problem discovered?
How is it that if the engine survived for 200 hours that suddenly it’s not a problem?
Richard H. February 14, 2023 At 6:31 pm
Great comment
Richard P. February 15, 2023 At 8:20 am
There have been zero reported failures (that is, the pin itself coming loose), but because it’s not impossible, it must be fixed. Apparently the ring can be seated properly if put in “backwards” but it’s more difficult, and if it’s still there in 200 hours, it must be seated.
Rick E. February 14, 2023 At 5:43 pm
I’ve never been a big fan of Continental Engines, but ever since our friends in China have taken ownership of the company, I’m even less of a fan.
Richard H. February 14, 2023 At 6:31 pm
Made in China! A shame.
T I. February 15, 2023 At 8:14 am
No, not “made in China”, owned by a Chinese parent company, as is Cirrus, Mooney, and other aviation entities
Tom C. February 14, 2023 At 9:22 pm
My guess is that the “preload on the mains” that was mentioned probably refers to the requirement for installation of torque plates when cylinders are removed, to keep adequate torque particularly on the thru-studs. So yes, that could be interpreted to mean “preload.
J’espères que cela ne s’applique pas à vous!
Jacques
By Paul Bertorelli, Published:February 13, 2023
Continental Aerospace Technologies Monday released a mandatory service bulletin describing how to inspect for improperly installed snap rings on about 2000 six-cylinder engines. The bulletin describes how to reseat the rings, if necessary, and also details warranty reimbursement.
The issue surfaced earlier this month when Continental notified Cirrus through a letter that snap rings had been improperly installed on engines and crankshafts manufactured between June 21, 2021, and Feb. 7, 2023. Continental said Monday that the problem was caused by improper assembly, not a defective part.
On its six-cylinder engines, Continental uses crankshaft counterbalance weights that move and suppress torsional or twisting loads on the crankshaft. The weights slide across a small range of motion and are able to respond to RPM shifts. They ride on pins held in place by the snap rings. The company says the snap rings were improperly installed and may not have seated fully in the groove designed to retain them.
The service bulletin requires inspecting the snap rings by removing one to three cylinders—variable with engine model—to gain access to the weights. The weights themselves do not have to be removed unless difficulties are encountered in seating the snap rings. Continental will loan a gauge to insert between the ears of the snap rings to determine if they’re fully seated. It also provides dimensions to field manufacture the gauge. The gap should be between 0.179 inch and 0.212 inch, depending on the engine model. The service bulletin describes how to reseat the rings if they are out of spec. The bulletin also advises techs to make sure the open end of the snap ring is oriented toward the crankshaft centerline.
Engines with more than 200 hours are exempt from the inspection, the reasoning being that if the rings allowed the pins and weight to depart, that would have occurred in the first 200 hours. It’s not known how many of the listed engines have accumulated this much flight time.
Continental will cover the cost of the work under warranty, for both engines and crankshafts. It will also establish a direct dial call center at 251-441-4460 for questions on the procedure.
Paul Bertorelli,
William . February 13, 2023 At 5:02 pm
Lousy situation but I respect them for taking responsibility and trying to make it right.
The obvious problem is that pulling cylinders will affect preload on the main bearings and this can lead to issues in the future, that will not likely be covered by warrantee.
Black B. February 14, 2023 At 1:02 pm
Preload on the mains? Detailed explanation needed please.
Never heard if it.
Paul B. February 15, 2023 At 7:49 am
A horizontally opposed aircraft engine is a light structure that carries a lot of load. It’s critical that the through studs holding the case together are torqued to the right value in the right order.
When cylinders are removed, if not done correctly, it can distort the torque loads on the case and thus the main bearings. This can cause them to spin in their mounts and fail. While this is not a common cause of engine failures, it happens frequently enough after cylinder work to raise real alarm about removing three cylinders from one side or even one cylinder.
Torque plates to hold the load temporarily are supposed to prevent this, but believe it or not, not all shops know how to do this properly. If it were my engine, I’d take it to a good engine shop where they’re more likely to know how to do it correctly.
Bob G. February 14, 2023 At 4:50 am
I had to look-up what a snap ring was – we call them circlips here in the UK.
Richard P. February 15, 2023 At 8:18 am
In the USA, we generally use “circlip” for the plain wire variety, often used to locate wrist [gudgeon] pins in the piston.
Joe P. February 14, 2023 At 8:28 am
“Continental said Monday that the problem was caused by improper assembly, not a defective part.: The kinda have to cover this. Improper assembly is never a good thing.
Ronnie S. February 14, 2023 At 10:11 am
I want to see what Continental and Cirrus call out for the acceptable time to perform this inspection. Usually they are way off and whats the shop rate they are figuring it on.
Rush S. February 14, 2023 At 11:49 am
Click on the “service bulletin” link for specifics. Replacement crankshaft assemblies allow for 0.15 hr inspection time, and 0.25 hr for replacement or adjustment (per counterweight).
For engines, add 10, 18, or 22 hours for cylinder removal, depending on whether the specific model requires pulling 1, 2, or 3 jugs.
Richard H. February 14, 2023 At 6:33 pm
Can’t believe those time estimates.
Richard P. February 15, 2023 At 8:18 am
Yeah, I think in 22 hours I can build an engine from the parts bin, and install it.
Cockpit p. February 14, 2023 At 11:49 am
Bad deal for new engine owners. You paid for a new engine, now have your local A&P tear it apart. Good luck.
Eric . February 14, 2023 At 12:34 pm
How many engines have had the pins and weights come apart?
How was this problem discovered?
How is it that if the engine survived for 200 hours that suddenly it’s not a problem?
Richard H. February 14, 2023 At 6:31 pm
Great comment
Richard P. February 15, 2023 At 8:20 am
There have been zero reported failures (that is, the pin itself coming loose), but because it’s not impossible, it must be fixed. Apparently the ring can be seated properly if put in “backwards” but it’s more difficult, and if it’s still there in 200 hours, it must be seated.
Rick E. February 14, 2023 At 5:43 pm
I’ve never been a big fan of Continental Engines, but ever since our friends in China have taken ownership of the company, I’m even less of a fan.
Richard H. February 14, 2023 At 6:31 pm
Made in China! A shame.
T I. February 15, 2023 At 8:14 am
No, not “made in China”, owned by a Chinese parent company, as is Cirrus, Mooney, and other aviation entities
Tom C. February 14, 2023 At 9:22 pm
My guess is that the “preload on the mains” that was mentioned probably refers to the requirement for installation of torque plates when cylinders are removed, to keep adequate torque particularly on the thru-studs. So yes, that could be interpreted to mean “preload.
J’espères que cela ne s’applique pas à vous!
Jacques