Prop is HC-H3YF-1RF with TSIO-550E on L-IVP

On Jul 21, 2013, at 11:13 PM, Colyn Case <colyncase [at] earthlink.net

> wrote:

Bob ,   Can you please specify the model number of the blades and hub?  More than one exist which match "78 inch Hartzell"

Colyn

Sent from my iPhone

On Jul 21, 2013, at 11:54 PM, Robert R Pastusek <rpastusek [at] htii.com

> wrote:

Gentlemen,

This is an alert for a potentially serious problem with the Continental IO/TSIO-550 engine/Hartzell 78” Scimitar propeller combination commonly used on Lancair aircraft. Please appreciate that this is from a very small data sample, and analysis is on-going, but it’s important enough to share what we now know. 

Lancair (N619SJ) owner Bob Rickard called last week to advise that he’d discovered a major crack in his crankshaft at the propeller flange and wanted to alert other owners flying the above engine/prop combination of his problem. 

Bob has been chasing a random vibration in his airframe since he bought the aircraft three years/approximately 500 hours ago. The “standard suspects” of prop balance/run-out, engine mount/isolators, engine contact with the cowling, etc. had been systematically ruled out over time. In frustration, and unwilling to just ignore it, Bob ordered a new MT 4-blade to replace the Hartzell, remaining very uncomfortable with the vibration and unable to think of any other possible fixes. Part of Bob’s discomfort was based on the fact that he’d talked extensively to Ed Smith who had similar vibration issues with the same engine/propeller combination. (Ed’s N9JE experienced an in-flight crankshaft failure/departure of the prop in 2010; Ed successfully dead-sticked the airplane onto a beach.)

Bob’s recent discovery of the cracked crankshaft was made when the Hartzell was removed for replacement with a new MT prop. At the time of removal/discovery, the engine had just more than 100 flight hours since major overhaul. The crankshaft had been checked for cracks at overhaul, and the actual eddy current test results were still available showing no cracks or irregularities at that time. Bob believes that the crack developed within the last 100 flight hours as a result of long-term exposure to harmonic vibration, and that this vibration could be a result of an incompatibility between his big-bore Continental and this specific Hartzell prop. He notes that although this is an “FAA approved” engine/propeller combination, he has talked to other airplane owners flying this combination who have/are experiencing similar vibration issues. 

We understand that Continental and the FAA have been notified of this problem, but we have no additional information at this time. LOBO expects to publish a more detailed report on this in the next monthly newsletter, but both Ed Smith and Bob Rickard felt this discovery was worth making immediate notification about. Specifically, any unusual or new engine vibration should be cause for immediate attention. Bob considers himself very lucky to have caught the crack before in-flight failure. 

We’ll devote a few minutes to share what we know/answer questions at our LOBO Safety Forum to be held at 1300 in Forum Pavilion 2, Monday, 29 August, at AirVenture. Bob Rickard won’t be available to discuss this at our safety forum, but you can email him at r.rickard [at] rcginc-us.com. LOBO would also appreciate an email or call (rpastusek [at] htii.com 757-286-4802) if you are experiencing similar problems.

Thanks,

Bob Pastusek

For LOBO

Bob Rickard

President, Rickard Consulting Group, Inc.

r.rickard [at] rcginc-us.com

RCG Logo for Email.jpg

If anyone is interested I can send them the Hartzell manual in .pdf

Bob,  there's a blade part and a hub part.

Bob,  there's a blade part and a hub part.

e.g. my full feathering is a 

HC-H3YF-2UF/FC7693DF which was the latest and greatest in 2004.

(It also has a TKS slinger ring and boots on it) 

On Jul 22, 2013, at 9:27 AM, Bob Rickard wrote:

Prop is HC-H3YF-1RF with TSIO-550E on L-IVP

Bob

On Jul 21, 2013, at 11:13 PM, Colyn Case <colyncase [at] earthlink.net

> wrote:

Bob ,   Can you please specify the model number of the blades and hub?  More than one exist which match "78 inch Hartzell"

Colyn

Sent from my iPhone

On Jul 21, 2013, at 11:54 PM, Robert R Pastusek <rpastusek [at] htii.com

> wrote:

Gentlemen,

 

This is an alert for a potentially serious problem with the Continental IO/TSIO-550 engine/Hartzell 78” Scimitar propeller combination commonly used on Lancair aircraft. Please appreciate that this is from a very small data sample, and analysis is on-going, but it’s important enough to share what we now know. 

 

Lancair (N619SJ) owner Bob Rickard called last week to advise that he’d discovered a major crack in his crankshaft at the propeller flange and wanted to alert other owners flying the above engine/prop combination of his problem. 

 

Bob has been chasing a random vibration in his airframe since he bought the aircraft three years/approximately 500 hours ago. The “standard suspects” of prop balance/run-out, engine mount/isolators, engine contact with the cowling, etc. had been systematically ruled out over time. In frustration, and unwilling to just ignore it, Bob ordered a new MT 4-blade to replace the Hartzell, remaining very uncomfortable with the vibration and unable to think of any other possible fixes. Part of Bob’s discomfort was based on the fact that he’d talked extensively to Ed Smith who had similar vibration issues with the same engine/propeller combination. (Ed’s N9JE experienced an in-flight crankshaft failure/departure of the prop in 2010; Ed successfully dead-sticked the airplane onto a beach.)

 

Bob’s recent discovery of the cracked crankshaft was made when the Hartzell was removed for replacement with a new MT prop. At the time of removal/discovery, the engine had just more than 100 flight hours since major overhaul. The crankshaft had been checked for cracks at overhaul, and the actual eddy current test results were still available showing no cracks or irregularities at that time. Bob believes that the crack developed within the last 100 flight hours as a result of long-term exposure to harmonic vibration, and that this vibration could be a result of an incompatibility between his big-bore Continental and this specific Hartzell prop. He notes that although this is an “FAA approved” engine/propeller combination, he has talked to other airplane owners flying this combination who have/are experiencing similar vibration issues. 

 

We understand that Continental and the FAA have been notified of this problem, but we have no additional information at this time. LOBO expects to publish a more detailed report on this in the next monthly newsletter, but both Ed Smith and Bob Rickard felt this discovery was worth making immediate notification about. Specifically, any unusual or new engine vibration should be cause for immediate attention. Bob considers himself very lucky to have caught the crack before in-flight failure. 

 

We’ll devote a few minutes to share what we know/answer questions at our LOBO Safety Forum to be held at 1300 in Forum Pavilion 2, Monday, 29 August, at AirVenture. Bob Rickard won’t be available to discuss this at our safety forum, but you can email him at r.rickard [at] rcginc-us.com. LOBO would also appreciate an email or call (rpastusek [at] htii.com 757-286-4802) if you are experiencing similar problems.

 

Thanks,

Bob Pastusek

For LOBO

<RCG Logo for Email.jpg>

Bob Rickard

President, Rickard Consulting Group, Inc.

r.rickard [at] rcginc-us.com

image.jpeg

Ed Martin's legacy is smooth.  Mine has had a lot of annoying vibes as you describe but virtually all have been removed with lots of cowling interference fixes and plug change.  Many pilots forget the alternator can be a wicked source of vibration and it is almost in the same plane as the prop.



The problems I had originally were in that freq range and visible at the wingtip also.



Paul



On 2013-07-25, at 9:54, Charles Brown <browncc1 [at] verizon.net> wrote:



>

> Has anyone definitely flown a vibration-free IO-550 Lancair (or TSIO-550) with *any* propeller?  And by vibration-free, I mean it is free of low-frequency 10-20Hz stuff, not the normal noise of flying.  What I'm wondering is...  is it the 550, making such vibration with *any* propeller?

>

> Charley Brown

> Legacy RG  280hr

>

>

So how do you get your alternator balanced?  non-aviation shops won't touch them and aviation shops don't want to open them



On Jul 25, 2013, at 10:21 AM, Paul Miller wrote:



Ed Martin's legacy is smooth.  Mine has had a lot of annoying vibes as you describe but virtually all have been removed with lots of cowling interference fixes and plug change.  Many pilots forget the alternator can be a wicked source of vibration and it is almost in the same plane as the prop.



The problems I had originally were in that freq range and visible at the wingtip also.



Paul



On 2013-07-25, at 9:54, Charles Brown <browncc1 [at] verizon.net> wrote:



>

> Has anyone definitely flown a vibration-free IO-550 Lancair (or TSIO-550) with *any* propeller?  And by vibration-free, I mean it is free of low-frequency 10-20Hz stuff, not the normal noise of flying.  What I'm wondering is...  is it the 550, making such vibration with *any* propeller?

>

> Charley Brown

> Legacy RG  280hr

>

>



--

For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html

The key point that this thread is about is a vibration that is NOT "normal".  The key indicator is a change in the magnitude of the vibration with a change in RPM.  There are enough of you out there that have responded to me directly that state you have made all attempts at correcting the "normal" vibration issues, ruling out alternators, cowl interference, motor mounts, dynamic balancing, crank counter weights, etc.  Those things are normal and would not likely cause damage to the crank prop flange if left untreated.  The problem we are discussing is related to the prop/engine combination.  

We have confirmed reports of 550 motors being smooth with McCauley props, Aerocomposite Props and MT props, to answer Charley's question below.  However, NO ONE has come forward and said "My 550 engine/Hartzell Scimitar 78" prop combination is smooth".  I would be very interested if someone out there can say that.  To the contrary, I have received multiple responses from 4 different aircraft types that say "I have dealt with this for a long time and can't fix it".  Now what?

Bob R

On Jul 25, 2013, at 9:21 AM, Paul Miller <pjdmiller [at] gmail.com

> wrote:

Ed Martin's legacy is smooth.  Mine has had a lot of annoying vibes as you describe but virtually all have been removed with lots of cowling interference fixes and plug change.  Many pilots forget the alternator can be a wicked source of vibration and it is almost in the same plane as the prop.

The problems I had originally were in that freq range and visible at the wingtip also.

Paul

On 2013-07-25, at 9:54, Charles Brown <browncc1 [at] verizon.net

> wrote:

Has anyone definitely flown a vibration-free IO-550 Lancair (or TSIO-550) with *any* propeller?  And by vibration-free, I mean it is free of low-frequency 10-20Hz stuff, not the normal noise of flying.  What I'm wondering is...  is it the 550, making such vibration with *any* propeller?

Charley Brown
Legacy RG  280hr

--
For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html

<RCG Logo for Email.jpg>

Bob Rickard

President, Rickard Consulting Group, Inc.

r.rickard [at] rcginc-us.com

My 550/hartzell scimitar is and has always been smooth.

1350hrs TT

Douglas Johnson MD

Sent from my iPad

On Jul 25, 2013, at 12:10 PM, Bob Rickard <r.rickard [at] rcginc-us.com

> wrote:

The key point that this thread is about is a vibration that is NOT "normal".  The key indicator is a change in the magnitude of the vibration with a change in RPM.  There are enough of you out there that have responded to me directly that state you have made all attempts at correcting the "normal" vibration issues, ruling out alternators, cowl interference, motor mounts, dynamic balancing, crank counter weights, etc.  Those things are normal and would not likely cause damage to the crank prop flange if left untreated.  The problem we are discussing is related to the prop/engine combination.  

We have confirmed reports of 550 motors being smooth with McCauley props, Aerocomposite Props and MT props, to answer Charley's question below.  However, NO ONE has come forward and said "My 550 engine/Hartzell Scimitar 78" prop combination is smooth".  I would be very interested if someone out there can say that.  To the contrary, I have received multiple responses from 4 different aircraft types that say "I have dealt with this for a long time and can't fix it".  Now what?

Bob R

On Jul 25, 2013, at 9:21 AM, Paul Miller <pjdmiller [at] gmail.com

> wrote:

Ed Martin's legacy is smooth.  Mine has had a lot of annoying vibes as you describe but virtually all have been removed with lots of cowling interference fixes and plug change.  Many pilots forget the alternator can be a wicked source of vibration and it is almost in the same plane as the prop.

The problems I had originally were in that freq range and visible at the wingtip also.

Paul

On 2013-07-25, at 9:54, Charles Brown <browncc1 [at] verizon.net

> wrote:

Has anyone definitely flown a vibration-free IO-550 Lancair (or TSIO-550) with *any* propeller?  And by vibration-free, I mean it is free of low-frequency 10-20Hz stuff, not the normal noise of flying.  What I'm wondering is...  is it the 550, making such vibration with *any* propeller?

Charley Brown
Legacy RG  280hr

--
For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html

<RCG Logo for Email.jpg>

Bob Rickard

President, Rickard Consulting Group, Inc.

r.rickard [at] rcginc-us.com

Here's the ticket for a stock Legacy prop, it's 70 inches as shown by the serial number (73 minus 3).  Rickard's LIV prop appears to be 76 inches, from the serial number.

<PastedGraphic-1.png>

I too have a vibration in my Legacy IO-550 and have had dynamic balance check out perfect.  It's around 20Hz, I'd guess, and the visible amplitude at the wingtips is about 1/4 inch.  Most passengers don't notice it; I normally cruise at 2300 rpm; it seems a little smoother at higher rpm.  I have a hard time believing that all Hartzell 3-blade props on all Lancair 550s, regardless of diameter and horsepower, have the same problem; but now I wonder.  

Just before Placerville I let the USAF's chief F-16 test pilot fly my Legacy and he commented immediately on the vibration.  I figured that's because he flies jets and gliders, neither of which ever vibrate...  but my friend's 2-blade RV-6 / O-320 doesn't have this vibration either...

Has anyone definitely flown a vibration-free IO-550 Lancair (or TSIO-550) with *any* propeller?  And by vibration-free, I mean it is free of low-frequency 10-20Hz stuff, not the normal noise of flying.  What I'm wondering is...  is it the 550, making such vibration with *any* propeller?

Charley Brown

Legacy RG  280hr

On Jul 23, 2013, at 6:37 AM, Steve Colwell wrote:

We have been chasing a vibration from the first few hours on our Legacy IO-550 with stock compression and a Hartzell 3 blade.  I don’t have easy access to the prop model but it is the standard Hartzell supplied by Lancair for the IO-550. 

Our vibration varies in magnitude with power setting and air speed.  It is most noticeable with control stick shake but also could be felt on the dust cover.   I went thru an exhaustive series of finding engine/cowl contact points, questioning gear doors, rechecking control surfaces, two prop balances and an engine rebuild (cracked case).  I thought it was almost fixed several times since it was not easily replicated.  Then it would come back, sometimes very slightly, other times worse. 

Actually, this is a relief to know what the likely problem is after 5 years and 400 hours of chasing a fix.  We just booked a Southwest round trip to OSH.  I really don’t want to be the next statistic.  Thanks Bob and Ed.

 

Steve

 

For no particular reason, I was browsing through the Continental Engine Maintenance and Overhaul Manual (M-18) for the TSIO-550 family of engines.  The engine specifications are listed on pages 2-22 through 2-33.  Each of these engines has a "Minimum Cruise RPM" of 2300 RPM.   I was unaware that there was any RPM restriction (other than max. RPM) on these engines.



I never go that low.  My minimum cruise RPM is 2400.



Does anyone use a cruise RPM below 2300?



Barry Knotts

LIV-P, N4XE

This is the shop that did ours.

Steve



Call these guys.

Aircraft Systems

5187 Falcon Road

Rockford, IL 61109-2986

(815) 399-0225

Terry Norris, Sr.



Craig Berland

N7VG



-----Original Message-----

From: Lancair Mailing List [lml [at] lancaironline.net (mailto:)

] On Behalf Of Steve

Colwell

Sent: Thursday, July 25, 2013 5:47 PM

To: lml [at] lancaironline.net

Subject: [LML] Potential Problem-Engine Vibration



I can find out from Bill Bainbridge of B&C at Airventure.  The shop he

recommended found a several built in problems with our Kelly rebuilt main

alt. when they balanced it.

Kyrillian, thanks.  I will check out this app.  I think a good place to put the iPhone would be to clamp it directly to the copilot's floorboard.



I have never had alarming vibration like Steve Colwell cites, so maybe we are talking about two entirely different situations.



I cruise at 2300.  Continental has had some crankshaft problems with engines that were cruised at 2200, but I forget the details and I'm not even sure they were 550s.  





On Jul 26, 2013, at 5:22 AM, Kyrilian Dyer wrote:



If you'd like to measure the frequency and amplitude of relatively low frequency vibration I'd recommend an iPhone app called 'Vibration' ($4.99 from the App Store).  It's certainly not high end but it may help in characterizing some of the vibrations that you guys describe. The only problem I see is that it only samples up to 100 Hz, which gives you frequency data up to 44.9 Hz (~2690 rpm).  This won't give you any data at propeller frequencies.  But it may help tell if its a function of RPM at 1/rev, or if it's asynchronous with the engine (and doesn't correlate with engine speed, such as buffet or flutter).



A few screenshots (recording of an out of balance car tire at 70 mph) are shown below. Note that the app can output data to a .csv file, which can be reviewed/analyzed later.  I do this sort of thing with proper accelerometers, recorders and analyzers on helicopters in my day job, so I'd like to help if I can.  If anyone has luck with the iPhone app please send me the data files.  Perhaps we could then compare between aircraft.



 Regards,

- Kyrilian

  L2K-236



Time display:

<image.png>



DFT (note spike at around 16 Hz)

<image.png>



Setup (one of several sub screens)

<image.png>





Sent from my iPhone

If you'd like to measure the frequency and amplitude of relatively low frequency vibration I'd recommend an iPhone app called 'Vibration' ($4.99 from the App Store).  It's certainly not high end but it may help in characterizing some of the vibrations that you guys describe. The only problem I see is that it only samples up to 100 Hz, which gives you frequency data up to 44.9 Hz (~2690 rpm).  This won't give you any data at propeller frequencies.  But it may help tell if its a function of RPM at 1/rev, or if it's asynchronous with the engine (and doesn't correlate with engine speed, such as buffet or flutter).

A few screenshots (recording of an out of balance car tire at 70 mph) are shown below. Note that the app can output data to a .csv file, which can be reviewed/analyzed later.  I do this sort of thing with proper accelerometers, recorders and analyzers on helicopters in my day job, so I'd like to help if I can.  If anyone has luck with the iPhone app please send me the data files.  Perhaps we could then compare between aircraft.

 Regards,

- Kyrilian

  L2K-236

Time display:

DFT (note spike at around 16 Hz)

Setup (one of several sub screens)

Sent from my iPhone

On Jul 25, 2013, at 8:46 PM, "Dennis Johnson" <pinetownd [at] volcano.net

> wrote:

I have a smooth running Legacy RG IO-550 with a three blade Hartzell
scimitar prop, HC-J3YF-1RF/F7391D-3/SM7. 

 

According to Hartzell's website, this is the recommended three blade
scimitar prop for the Legacy RG with IO-550 engine.  It is a 72" diameter
prop, not the 78" prop mentioned in Bob R's posting.  I thought all the
scimitar props on Legacys were the same as mine.

 

http://hartzellprop.com/pilots/kit-builders/legacy-2000-io-550-n-3-blade/

 

I consider mine to be "smooth," but that is a terribly subjective
concept.  However, I can say for sure that I do not feel vibration in the
stick and don't see any aileron vibration or wing tip
vibration.  Another Legacy builder and pilot commented on how smooth
mine is, but maybe he was just being polite.   

 

Unless there is a way to quantify "vibration" and "smoothness," I don't see
how we can accurately communicate about this.  One person's rough could be
another person's smooth.  Maybe if someone had a video of stick shake
or aileron shake?  A glass of water sitting on the glare
shield? 

 

Dennis

Legacy 625 hours 

 

 

 

 

 

 

 

 

image.png

image.png

image.png

 

Attachment: IMG_1196_2[9].jpg 

(61K)

 

Attachment: IMG_1197_2[11].jpg 

(57K)

 

Attachment: IMG_1200_2[15].jpg 

(58K)

The other related variable on prop blades is "runout" or "blade tracking." Although it's as severe as with different pitch angles, ;but significant variation between blade tracking can also be a cause of vibration. Always worth checking as part of these checks.



Bob



-----Original Message-----

From: Lancair Mailing List [lml [at] lancaironline.net (mailto:)

] On Behalf Of Craig Schulze

Sent: Friday, July 26, 2013 12:48 PM

To: lml [at] lancaironline.net

Subject: [LML] Re: Potential Problem-Engine Vibration



It sounds to me that you may have an issue with your prop hub not changing the pitch exactly the  same on all the blades.  The vibration you are feeling is one blade taking a larger bite of air and then causing everything to wobble.  It settles in sometimes but when you change the power setting the pitch on the prop is adjusted by the hub unevenly.  



Blue Skies,

Craig Schulze

Lancair N73S





On Jul 25, 2013, at 1:22 PM, "Steve Colwell" <mcmess1919 [at] yahoo.com> wrote:



In the first 40 hours I had vibration so severe it caused stick shake.  This has continued intermittently more or less for almost 400 hours.



First I found and fixed several Cowl Interference locations, then adjusted and notched the hat section of the nose gear door.



At about 50 hours I paid Barrett to tear down the engine to replace the Performance pistons (prematurely worn top rings) with stock ECI pistons.

Also found a cracked case.



We had the Kelly Alternator balanced and rebuilt at a shop recommended by Bill Bainbridge of B & C.  Sorry I can't remember the name, the Legacy file is in Texas.



I rounded the leading edges of the elevator counter weights when building so I temporarily squared them off to go back to the stock shape for testing.



All gear doors were checked in flight with video camera.



The pitch trim hinge pin had play, I replaced it per Chris Zavatson's web page.



Along the way the prop was balanced twice.



I could not get more that the usual vibration (which always seemed to be too

much) on test flights.  Then, unpredictably, vibration magnitude would increase with power reduction on some later flight.  I say unpredictably because I could not get increased vibration by attempting to duplicate previous conditions.  Let's hope a solution surfaces at Airventure.



Steve Colwell  Legacy RG IO550-N with Hartzell 3 Blade







-----Original Message-----

From: Lancair Mailing List [lml [at] lancaironline.net (mailto:)

] On Behalf Of Paul Miller

Sent: Thursday, July 25, 2013 7:22 AM

To: lml [at] lancaironline.net

Subject: [LML] Re: Potential Problem-Engine Vibration



Ed Martin's legacy is smooth.  Mine has had a lot of annoying vibes as you describe but virtually all have been removed with lots of cowling interference fixes and plug change.  Many pilots forget the alternator can be a wicked source of vibration and it is almost in the same plane as the prop.



The problems I had originally were in that freq range and visible at the wingtip also.



Paul







--

For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html

On what data do you make this assessment?



Danny

LNC2-360 Mk-II

Nothing is foolproof to the sufficiently talented fool.



-----Original Message-----

From: Craig Schulze [craig [at] skybolt.net (mailto:)

]

Sent: Friday, July 26, 2013 12:48 PM

To: lml [at] lancaironline.net

Subject: [LML] Re: Potential Problem-Engine Vibration



It sounds to me that you may have an issue with your prop hub not changing

the pitch exactly the  same on all the blades.  The vibration you are

feeling is one blade taking a larger bite of air and then causing everything

to wobble.  It settles in sometimes but when you change the power setting

the pitch on the prop is adjusted by the hub unevenly.  



Blue Skies,

Craig Schulze

Lancair N73S





On Jul 25, 2013, at 1:22 PM, "Steve Colwell" <mcmess1919 [at] yahoo.com> wrote:



In the first 40 hours I had vibration so severe it caused stick shake.  This

has continued intermittently more or less for almost 400 hours.



First I found and fixed several Cowl Interference locations, then adjusted

and notched the hat section of the nose gear door.



At about 50 hours I paid Barrett to tear down the engine to replace the

Performance pistons (prematurely worn top rings) with stock ECI pistons.

Also found a cracked case.



We had the Kelly Alternator balanced and rebuilt at a shop recommended by

Bill Bainbridge of B & C.  Sorry I can't remember the name, the Legacy file

is in Texas.



I rounded the leading edges of the elevator counter weights when building so

I temporarily squared them off to go back to the stock shape for testing.



All gear doors were checked in flight with video camera.



The pitch trim hinge pin had play, I replaced it per Chris Zavatson's web

page.



Along the way the prop was balanced twice.



I could not get more that the usual vibration (which always seemed to be too

much) on test flights.  Then, unpredictably, vibration magnitude would

increase with power reduction on some later flight.  I say unpredictably

because I could not get increased vibration by attempting to duplicate

previous conditions.  Let's hope a solution surfaces at Airventure.



Steve Colwell  Legacy RG IO550-N with Hartzell 3 Blade







-----Original Message-----

From: Lancair Mailing List [lml [at] lancaironline.net (mailto:)

] On Behalf Of Paul

Miller

Sent: Thursday, July 25, 2013 7:22 AM

To: lml [at] lancaironline.net

Subject: [LML] Re: Potential Problem-Engine Vibration



Ed Martin's legacy is smooth.  Mine has had a lot of annoying vibes as you

describe but virtually all have been removed with lots of cowling

interference fixes and plug change.  Many pilots forget the alternator can

be a wicked source of vibration and it is almost in the same plane as the

prop.



The problems I had originally were in that freq range and visible at the

wingtip also.



Paul







--

For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html

It's really only a guess.  But if you think about it the only thing changing with a throttle change is pitch.  



Blue Skies,

Craig



On Jul 26, 2013, at 10:45 AM, "Danny" <danny [at] n107sd.com> wrote:



> On what data do you make this assessment?

>

> Danny

> LNC2-360 Mk-II

> Nothing is foolproof to the sufficiently talented fool.

>

> -----Original Message-----

> From: Craig Schulze [craig [at] skybolt.net (mailto:)

]

> Sent: Friday, July 26, 2013 12:48 PM

> To: lml [at] lancaironline.net

> Subject: [LML] Re: Potential Problem-Engine Vibration

>

> It sounds to me that you may have an issue with your prop hub not changing

> the pitch exactly the  same on all the blades.  The vibration you are

> feeling is one blade taking a larger bite of air and then causing everything

> to wobble.  It settles in sometimes but when you change the power setting

> the pitch on the prop is adjusted by the hub unevenly.  

>

> Blue Skies,

> Craig Schulze

> Lancair N73S

>

>

> On Jul 25, 2013, at 1:22 PM, "Steve Colwell" <mcmess1919 [at] yahoo.com> wrote:

>

> In the first 40 hours I had vibration so severe it caused stick shake.  This

> has continued intermittently more or less for almost 400 hours.

>

> First I found and fixed several Cowl Interference locations, then adjusted

> and notched the hat section of the nose gear door.

>

> At about 50 hours I paid Barrett to tear down the engine to replace the

> Performance pistons (prematurely worn top rings) with stock ECI pistons.

> Also found a cracked case.

>

> We had the Kelly Alternator balanced and rebuilt at a shop recommended by

> Bill Bainbridge of B & C.  Sorry I can't remember the name, the Legacy file

> is in Texas.

>

> I rounded the leading edges of the elevator counter weights when building so

> I temporarily squared them off to go back to the stock shape for testing.

>

> All gear doors were checked in flight with video camera.

>

> The pitch trim hinge pin had play, I replaced it per Chris Zavatson's web

> page.

>

> Along the way the prop was balanced twice.

>

> I could not get more that the usual vibration (which always seemed to be too

> much) on test flights.  Then, unpredictably, vibration magnitude would

> increase with power reduction on some later flight.  I say unpredictably

> because I could not get increased vibration by attempting to duplicate

> previous conditions.  Let's hope a solution surfaces at Airventure.

>

> Steve Colwell  Legacy RG IO550-N with Hartzell 3 Blade

>

>

>

> -----Original Message-----

> From: Lancair Mailing List [lml [at] lancaironline.net (mailto:)

] On Behalf Of Paul

> Miller

> Sent: Thursday, July 25, 2013 7:22 AM

> To: lml [at] lancaironline.net

> Subject: [LML] Re: Potential Problem-Engine Vibration

>

> Ed Martin's legacy is smooth.  Mine has had a lot of annoying vibes as you

> describe but virtually all have been removed with lots of cowling

> interference fixes and plug change.  Many pilots forget the alternator can

> be a wicked source of vibration and it is almost in the same plane as the

> prop.

>

> The problems I had originally were in that freq range and visible at the

> wingtip also.

>

> Paul

>

>

>

> --

> For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html

>

It sounds like accelerometers mounted in suspect
locations with the engine running at the RPM indicated by the spike shown by the
Apple app. would lead you to the culprit.

 

Wolfgang

 

----- Original Message -----

From:
john [at] jjts.net.au (John Smith)

To: lml [at] lancaironline.net

Sent: Friday, July 26, 2013 12:47
PM

Subject: Re: [LML] Re: Potential
Problem-Engine Vibration

Kryilian,

I too have this vibration phenomenon in VH-XTZ ? I spent hours and hours
of flying time trying to isolate it, trying different power settings,
different aircraft loading, different angles of attack, you name it ? I could
not find a pattern. Mostly its there, but occasionally nothing. Visually, it
manifests itself with a very slight port wing tip / aileron quiver;
physically, you can mainly feel it ever so slightly in the rudder pedals.
Having said all this, others fly in the aircraft and don't know what I'm on
about.  But, I have now found that running at about 2540rpm is quite
smooth and all but gets rid of the vibration. Its noticeably worse at say 2400
? 2450rpm.

So ? endeavouring to quantify things, I employed the iPhone App you have
mentioned.  The attached pics are from way back in 2011; these should
give everyone an idea of what can be produced. Below my comments at the time
wrt to attached samples.

As one of our other forum contributors mentioned, vibration is very
subjective without the use of measurement devices? so can I suggest that those
whip have access to iPhones go flying and capture outputs in the same manner
and with same engine settings ? how about with iPhone resting on centre
console and engine set at 2500rpm, 19" and leaned 28degC (50degF) rich of
peak?. Or as anyone else might suggest otherwise.  Then we can all
collect data that should be legitimately comparable, and perhaps identify if
there are any substantial differences in the vibration characteristics.
Anyways, just an idea?.

Comments from tests in August 2011:-

Captured
three outputs with 2400rpm and about 19? MAP.  First sample with iPhone
on the centre console shows a spike at ~20Hz ? that is approx. equivalent to
1200rpm, which exactly half the engine engine rpm. For other two samples,
iPhone on the dust cover in the middle and then a bit to one side; these show
the same 20Hz spike, and also a spike around 38 - 40Hz ? this would seem to be
close to the engine rpm, but 38Hz is equivalent to 2280rpm, which does not
make sense as there is no way the engine rpm varies by that much. So, I?m not
sure what all this means. I?d love to get the iPhone onto the rudder pedals,
but that?s kind of tricky! The iPhone doesn?t measure above 50Hz, so I can
detect prop beat or exhaust beat.

Regards,

John


John N G Smith
Tel / fax:
   +61-8-9385-8891
Mobile:
     +61-409-372-975
Email:
        john [at] jjts.net.au

From: Kyrilian Dyer <kyrilian_av [at] yahoo.com

>
Reply-To: Lancair Mailing List <lml [at] lancaironline.net

>
Date: Friday, 26 July 2013 6:22 PM
To: <lml [at] lancaironline.net

>
Subject: [LML] Re: Potential Problem-Engine
Vibration

If you'd like to measure the frequency and amplitude of relatively low
frequency vibration I'd recommend an iPhone app called 'Vibration' ($4.99
from the App Store).  It's certainly not high end but it may help in
characterizing some of the vibrations that you guys describe. The only
problem I see is that it only samples up to 100 Hz, which gives you
frequency data up to 44.9 Hz (~2690 rpm).  This won't give you any data
at propeller frequencies.  But it may help tell if its a function of
RPM at 1/rev, or if it's asynchronous with the engine (and doesn't correlate
with engine speed, such as buffet or flutter).

A few screenshots (recording of an out of balance car tire at 70 mph)
are shown below. Note that the app can output data to a .csv file, which can
be reviewed/analyzed later.  I do this sort of thing with proper
accelerometers, recorders and analyzers on helicopters in my day job, so I'd
like to help if I can.  If anyone has luck with the iPhone app please
send me the data files.  Perhaps we could then compare between
aircraft.

 Regards,

- Kyrilian

  L2K-236

Time display:

DFT (note spike at around 16 Hz)

Setup (one of several sub screens)

Sent from my iPhone

On Jul 25, 2013, at 8:46 PM, "Dennis Johnson" <pinetownd [at] volcano.net

>
wrote:

I have a smooth running Legacy RG IO-550 with a three blade Hartzell
scimitar prop, HC-J3YF-1RF/F7391D-3/SM7. 

 

According to Hartzell's website, this is the recommended three blade
scimitar prop for the Legacy RG with IO-550 engine.  It is a 72"
diameter prop, not the 78" prop mentioned in Bob R's posting.  I
thought all the scimitar props on Legacys were the same as mine.

 

http://hartzellprop.com/pilots/kit-builders/legacy-2000-io-550-n-3-blade/

 

I consider mine to be "smooth," but that is a terribly subjective
concept.  However, I can say for sure that I do not feel vibration in
the stick and don't see any aileron vibration or wing tip
vibration.  Another Legacy builder and pilot commented on how
smooth mine is, but maybe he was just being polite.   

 

Unless there is a way to quantify "vibration" and "smoothness," I
don't see how we can accurately communicate about this.  One person's
rough could be another person's smooth.  Maybe if someone had a
video of stick shake or aileron shake?  A glass of water sitting on
the glare shield? 

 

Dennis

Legacy 625 hours 

 

 

 

 

 

 

 

---

---

---

That is a possibility I had not considered, I will ask Hartzell about it.  Another possibility is the movable crankshaft counter weights failing to position correctly.

Steve Colwell 

---

From: Craig Schulze <craig [at] skybolt.net

>
To: Steve Colwell <mcmess1919 [at] yahoo.com

>
Cc: "lml [at] lancaironline.net

" <lml [at] lancaironline.net

>
Sent:
Friday, July 26, 2013 7:42 AM
Subject: Re: Potential Problem-Engine Vibration

It sounds to me that you may have an issue with your prop hub not changing the pitch exactly the  same on all the blades.  The vibration you are feeling is one blade taking a larger bite of air and then causing everything to wobble.  It settles in sometimes but when you change the power setting the pitch on the prop is adjusted by the hub unevenly. 

Blue Skies,
Craig Schulze
Lancair N73S


On Jul 25, 2013, at 1:22 PM, "Steve Colwell" <mcmess1919 [at] yahoo.com

> wrote:

In the first 40 hours I had vibration so severe it caused stick shake.  This
has continued intermittently more or less for almost 400 hours.

First I found and fixed
several Cowl Interference locations, then adjusted
and notched the hat section of the nose gear door.

At about 50 hours I paid Barrett to tear down the engine to replace the
Performance pistons (prematurely worn top rings) with stock ECI pistons.
Also found a cracked case.

We had the Kelly Alternator balanced and rebuilt at a shop recommended by
Bill Bainbridge of B & C.  Sorry I can't remember the name, the Legacy file
is in Texas.

I rounded the leading edges of the elevator counter weights when building so
I temporarily squared them off to go back to the stock shape for testing.

All gear doors were checked in flight with video camera.

The pitch trim hinge pin had play, I replaced it per Chris Zavatson's web
page.

Along the way the prop was balanced twice.

I could not get more that the usual vibration (which always seemed to be too
much) on test flights.  Then,
unpredictably, vibration magnitude would
increase with power reduction on some later flight.  I say unpredictably
because I could not get increased vibration by attempting to duplicate
previous conditions.  Let's hope a solution surfaces at Airventure.

Steve Colwell  Legacy RG IO550-N with Hartzell 3 Blade



-----Original Message-----
From: Lancair Mailing List [mailto:lml [at] lancaironline.net

] On Behalf Of Paul
Miller
Sent: Thursday, July 25, 2013 7:22 AM
To: lml [at] lancaironline.net

Subject: [LML] Re: Potential Problem-Engine Vibration

Ed Martin's legacy is smooth.  Mine has had a lot of annoying vibes as you
describe but virtually all have been removed with lots of cowling
interference fixes and plug change.  Many
pilots forget the alternator can
be a wicked source of vibration and it is almost in the same plane as the
prop.

The problems I had originally were in that freq range and visible at the
wingtip also.

Paul

WHAT?  That makes no sense at all.  Where did you ever get such an idea?

 

Danny

LNC2-360 Mk-II

Nothing is foolproof to the sufficiently talented fool.

 

From: Craig Schulze [craig [at] skybolt.net (mailto:)

]
Sent: Sunday, July 28, 2013 2:21 PM
To: lml [at] lancaironline.net

Subject: [LML] Re: Potential Problem-Engine Vibration

 

It could be possible for wear or manufacturing process to allow one blade to have more play in pitch operation than the others. 

Blue Skies,

Craig Schulze 

On Jul 27, 2013, at 5:36 PM, vtailjeff [at] aol.com

wrote:

How is that mechanically possible? All blades are attached to the same pitch change mechanisms Elton 

 

J

Sent from my iPad

On Jul 27, 2013, at 12:34 PM, Steve Colwell <mcmess1919 [at] yahoo.com

> wrote:

That is a possibility I had not considered, I will ask Hartzell about it.  Another possibility is the movable crankshaft counter weights failing to position correctly.

Steve Colwell 

 

 

---

From: Craig Schulze <craig [at] skybolt.net

>
To: Steve Colwell <mcmess1919 [at] yahoo.com

>
Cc: "lml [at] lancaironline.net

" <lml [at] lancaironline.net

>
Sent: Friday, July 26, 2013 7:42 AM
Subject: Re: Potential Problem-Engine Vibration

It sounds to me that you may have an issue with your prop hub not changing the pitch exactly the  same on all the blades.  The vibration you are feeling is one blade taking a larger bite of air and then causing everything to wobble.  It settles in sometimes but when you change the power setting the pitch on the prop is adjusted by the hub unevenly. 

Blue Skies,
Craig Schulze
Lancair N73S


On Jul 25, 2013, at 1:22 PM, "Steve Colwell" <mcmess1919 [at] yahoo.com

> wrote:

In the first 40 hours I had vibration so severe it caused stick shake.  This
has continued intermittently more or less for almost 400 hours.

First I found and fixed several Cowl Interference locations, then adjusted
and notched the hat section of the nose gear door.

At about 50 hours I paid Barrett to tear down the engine to replace the
Performance pistons (prematurely worn top rings) with stock ECI pistons.
Also found a cracked case.

We had the Kelly Alternator balanced and rebuilt at a shop recommended by
Bill Bainbridge of B & C.  Sorry I can't remember the name, the Legacy file
is in Texas.

I rounded the leading edges of the elevator counter weights when building so
I temporarily squared them off to go back to the stock shape for testing.

All gear doors were checked in flight with video camera.

The pitch trim hinge pin had play, I replaced it per Chris Zavatson's web
page.

Along the way the prop was balanced twice.

I could not get more that the usual vibration (which always seemed to be too
much) on test flights.  Then, unpredictably, vibration magnitude would
increase with power reduction on some later flight.  I say unpredictably
because I could not get increased vibration by attempting to duplicate
previous conditions.  Let's hope a solution surfaces at Airventure.

Steve Colwell  Legacy RG IO550-N with Hartzell 3 Blade



-----Original Message-----
From: Lancair Mailing List [mailto:lml [at] lancaironline.net

] On Behalf Of Paul
Miller
Sent: Thursday, July 25, 2013 7:22 AM
To: lml [at] lancaironline.net

Subject: [LML] Re: Potential Problem-Engine Vibration

Ed Martin's legacy is smooth.  Mine has had a lot of annoying vibes as you
describe but virtually all have been removed with lots of cowling
interference fixes and plug change.  Many pilots forget the alternator can
be a wicked source of vibration and it is almost in the same plane as the
prop.

The problems I had originally were in that freq range and visible at the
wingtip also.

Paul