SB for Crank shaft Journal inspection

[Rich]

View The Video

Rotax announces Service Bulletin SB-912-064 / SB-914-045 :

 

Mandatory.

 

 

I just received this notification by E-mail. My engine is affected. SN/ULS 6 779 300, manufactured in 2011.

 

Check your engine SN to see if future compliance is mandated.

 

Rich

[Rich]

Sorry for the small print.--------Rich

[FastEddieB]

Ouch!

 

Mine (manufactured 2007- #5648194) seems not to be in the range.

 

The actual check seems pretty easy - with the tool mentioned another few minutes when you pull the magnetic plug at scheduled oil changes.

 

Not so pretty if the little gauge slides in too far though!

 

(note: you can select the text and make it any size you want, even after posting.)

 

(note2: for some reason I found the presenter in the video unintentionally hilarious at times! )

[Jim Meade]

I don't recall the context so you'll have to refresh my memory.

[Rich]

Roger,

 

Worse case scenario. If the journal was cracked, what is the approx cost for the fix? Does Rotax offer any monatary reimbursement for a low time engine (100-200 hrs)?

 

I plan on ordering the tool and checking at every oil change. Do I need an A&P to sign it off?

 

Rich

[Rich]

Eddie,

 

Thanks for the tip on print size.

The pronunciation on the Rotax video's is VERY precise. Haven't seen that fellow before.

 

Rich

[Jim]

The implication here is that the engine will start and fly with the crankshaft broke. Is this true?

[Rich]

Thanks Roger,

 

Have you seen this happen before? Does an SB like this come out after one incident or after a certain number?

 

Can I check this w/o an A&P sign off?

 

Thanks again,

Rich

[Doug G.]

That had me concerned. My plane is a 2010, but the engine was manufactured in 2009 and the serial number is not included. The test is not that big a deal, but a problem with the crank would be. I hope it is simply a matter of using the gauge for you Rich.

[Dan Kent]

This also applies to my engine. Looks like I'll be ordering the tool and finding a local A&P to do the test. Right now I think I'm going to test it right away and then as perscribed (of course it depends on how long it takes to get the tool). I have 180 hours on the engine.

[Rich]

Dan, and others needing the Rotax tool # 876-260 to check the crankshaft journal.

 

If you call Lockwood at 1-863-655-6229 (press 3 for maintenance) Dean will put you on an E-mail list and you'll be notified when they receive the tools from Rotax.

 

Call times are from 9-10AM and 2-3PM eastern time.

 

Rich

[FlyingMonkey]

My engine is outside the affected range, whew.

[Dan Kent]

Dan, and others needing the Rotax tool # 876-260 to check the crankshaft journal.

 

If you call Lockwood at 1-863-655-6229 (press 3 for maintenance) Dean will put you on an E-mail list and you'll be notified when they receive the tools from Rotax.

 

Call times are from 9-10AM and 2-3PM eastern time.

 

Rich

 

Thanks Rich. I just got off the phone with Dean and am on the email list. One of the things he told me was that a flight school had an engine from the earlier SB group that flew approximately 3 months with the crankshaft broken. When the plane was brought in for an 100 inspection the mechanic pulled off the gearbox and he end of the crankshaft came with it. The flight school operator did mention that there were some unusual vibrations.

 

I still can't get my head around how a broken crankshaft can still drive the prop, but Dean (as Roger said earlier) that it will continue to operate. He did say to pay particular attention to your oil pressure.

 

EDIT: I went back and looked at the SB again and on pg 10 the last illustration shows where the break happens. Now I understand.

[FlyingMonkey]

I still can't get my head around how a broken crankshaft can still drive the prop, but Dean (as Roger said earlier) that it will continue to operate. He did say to pay particular attention to your oil pressure.

 

If it breaks longitudinally, I can see the two halves keeping each other in place and still turning if they are held tightly enough in the gearbox bearings.

[Dan Kent]

According to the SB, it shears outbound (toward the front of the engine) of the gear, so it is between the front of the gearbox case and the gear on the crankshaft (basically at the front end of the crankshaft).

 

I asked Dean if there was any in between failure and he said because that nut it torqued to 148 ft-lbs, it is not going to crack, but either hold or break (shear).

[FastEddieB]

I am guessing this is an issue for earlier engines.

 

Better to say, a certain range of engines.

 

Much earlier ones were similarly not affected.

[Dan Kent]

 

I am guessing this is an issue for earlier engines.

 

My plane was built in mid to late 2011, and I took delivery in early 2012. Rich got his plane after mine, so it isn't too much earlier.

[liltaka]

Cracked / Broken crankshafts...That is right up my alley.

 

You can not check cracks in crankshaft with your naked eyes, unless you have a magnetic particle fluid & light.

Cracks which can cause crankshaft to break can be in microns...You can definitely see broken though...I would assume this notice is to change all crankshafts between the serial numbers.

 

If you would like to know...

 

There are several reasons why crankshaft breaks during the operation.

1. Bearings are not floating on main journals & pin journals as freely due to oil hole blockage

2. Journals are not machined properly

3. Crankshaft was not forged properly and folded material, inclusions

4. Induction hardening or fillet roll of main & pin journals did not hardened the material correctly

5. Crankshaft was not balanced within the specified tolerance

6. Too much torque can also break crankshaft (depends on material & specs)

 

Only way to ensure your safety, change cranksahft, don't just check with your naked eyes and thinking it's ok.

 

taka

[liltaka]

One more info.

912 crankshaft has 4 pin & 3 main journals. Pins are where connecting rods connects & mains sits right on crank casing. This service bulletin says front, so post end without the fly wheel is mounted on. Weired part is that cranks are breaking from the #1 main. Usually crank break from pin journal thrust wall since those areas deals with more stress from combustions...

[CRANKY]

In South Africa 21 October 2013 one of the affected engines came to an abrupt stop at 300 hours with a broken crank, so don’t think that your engine is going to take you to the next 100 hour inspection. The Rotax distributor is offering………….. No, not a new engine. A new crank shaft and that is it !!!! If the recall of each of these engines were to cost BRP Powertrain $ 5,000, that would cost the company $18,500,000. Will they be able to take the punch? This might explain the absurd 100 hour inspection regime for a manufacturing defect that could result in sudden engine stoppage at any time and without warning. Potentially this could break the company if not your neck.

[Dan Kent]

I just spoke with Lockwood and they have the part in to test this. They are renting them out @ $15. They charge your credit card for the full value of the gauge (around $100 (I forgot to write down the exact amount)) and then credit back everything but $15 when it is returned. They said they would like to get them back within a week or so.

[Rich]

Dan,

 

I received that E-mail from lockwood also. I've decided to wait for the tool and keep a close eye on my oil pressure.

 

Rich

[Dan Kent]

I thought I would do the initial test just for peace of mind. My oil pressures have been very steady, but still want to do initial test.

[Rich]

S.O.

 

Thanks for that information.

 

The tool's cost would have been approx $95.

[Dan Kent]

The test on my engine was done today and it passed. I have about 190 hrs on the engine.

 

I have the Honeywell oil pressure sensor and in level flight my oil pressures hover between 55 to 60 psi. I started watching my oil pressure very closely after the sb.