Is it my plane, or is it me?

[FFSchooley]

Hey all,
It’s me again. I was hoping my next post would be my “I just soloed!” Post, but instead I am seeking all of your advice. I am supposed to solo tomorrow which I want to be excited about, but as usual there seems to be something wrong with my plane. So I want to ask all of your for your opinion on what you would do.

I thought I had everything finally sorted out on my plane thanks to all your help, my mechanics help, and lots and lots of money. I went up my first lesson yesterday after the spark plug issue and after a few laps notice that the vibration I used to have was back. I have gotten used to my yoke shaking a bit, but it seemed to be back to how it was before, visibly shaking really bad. It’s less at cruise, but at climb out or lower rpm is bad. Then I notice on climb out my rear pilot side lift strut is visibly vibrating up and down. It’s shaking. But it stops at cruise, when the vibration is less. Maybe it’s always done this and I just didn’t notice? Anyways, Compound this with my stupid engine monitor showing number 1 CHT bouncing all over the place (must be the probe, as CHT can’t go back and fourth from 150 to 250 in a matter of a second.), let’s just say I didn’t learn much that day. My instructor was frustrated that I wasn’t listening, but it was hard to pay attention to him as I watch my plane shake and red lights flash.

with all that said, am I worrying about this stuff to much? Do I need to just relax and accept that a 1959 plane is going to rattle and shake and have constant little issues? Am I just scarred from having to fix this mess of a plane that was poorly put together and poorly maintained? Do I just need to ignore this stuff and just fly? I mean, the engine hasn’t blown up in all these years and the plane hasn’t vibrated apart yet, so it’s probably all fine, right? My instructor doesn’t say anything, so I assume he isn’t concerned. I just don’t know if I am expecting too much or if there is something truly wrong with my plane. I don’t see other planes shaking and vibrating when I watch YouTube, but maybe they are and I just don’t see it. Is this all normal for old planes?

Anyways, I couldn’t sleep and was hoping to get some advice from those those have much more experience than me. Tell me, what would you do? Should I have more confidence in this old bird and all the work that has been done fly the crap out of this thing, or do I need to not be flying this thing and figure out was is still wrong?

thanks in advance for the help.

brett

 

[walt.buskey]

As I mentioned before, we're apparently in the same boat here... The fellow I bought my plane from flew it for 6 years and 400+ hrs with no real issues, but the overall condition of the thing was pretty shaky when I got it and started digging into it. I've replaced or repaired so many things now I can't remember them all. So now we're ready to get it back in the air and my A&P puts an electronic accelerometer thing on it and says it vibrates too much -- "Dangerous Vibration" was the message his device displayed, in fact.

So we're going through stuff now, but so far nothing has "cured" it. So I was thinking... maybe that's just its nature?

Then I thought some more: very many of the issues I've corrected COULD have been caused --or at the very least exacerbated-- by excessive vibration, as it turns out. In thinking about all the stuff I've fixed, that vibration issue keeps rearing its head....

Not sure where we're going to go after the next test (right mag was just overhauled), but it's beginning to sound like perhaps minimal effort was involved when the engine was rebuilt 740+/- hrs ago -- both my A&P and another A&P had the same thought: when it was overhauled, they didn't bother to weigh/balance any of the new parts in the engine before they put it all together.

I've never been involved in an O-320 overhaul, but that's what they both thought. Interesting, and given the number of observed "shortcuts" elsewhere in the plane, a distinct possibility -- but what do I know?

You might see if your A&P can get a quantitative analysis on your engine -- see if he's got an accelerometer to verify if engine vibration levels are really out of line.

So, Brett, I'm scratching my head, too!

One thing I will say, however, is that I'm in this to the end, even if it involves pulling that engine out, to determine who the ^%$ is going on. Hang in there.

Walt

 

[Pacer42Z]

The two general sources of vibration are the engine and the prop. If the prop hasn’t been overhauled for a long time, I would start there. It is not that expensive. Then make sure the prop is mounted in the correct position.

Juergen
Pacer N3342Z

 

[Frank Green]

42Z you are spot on. When I overhauled my plane 10 years ago I had the prop overhauled and then reinstalled it with instructions from the SWPC site which are still on Andy's site. When my prop stopped it was almost always 12-6 oclock position. And I had a noticeable vibration. At annual this year when I reinstalled the prop I used the instructions on the Sensenich website and the vibration is way less than it was. The prop now stops at 2-8 oclock when standing in front like you were going to hand prop. The 12 position was better if I have to hand prop it but that is rare.

 

[Gilbert Pierce]

The rapid oscillation of the CHT is most likely a bad connection in the CHT wiring. I have had this issue on several occasions.

If its an EI gauge with spade connectors, taking the apart and reconnecting them will cure it for awhile. EI has a replacement connector that cures the problem. They use to send them for free.

Does your instructor think it vibrates too much?

 

[FFSchooley]

It’s not my prop fellas, it’s been overhauled and clocked in various positions, no luck.

Gilbert, it’s an EI gauge, so I will check the connectors. my instructor hasn’t said anything, but I have also never asked.

Im with Walt, I believe we have tackled everything but the engine at this point. If it is the engine, well... that will be out of my price range for quite some time.

back to my original question, do I just live with this? Is it normal for these planes to vibrate? Am I crazy trying to chase down having a smooth running plane? Should my lift strut be vibrating? Can I just fly this thing and enjoy?

 

[smcnutt]

I think it's hard to say what you're feeling is "normal" from way out here in the internet. I would certainly start a little closer to the issue and ask your instructor while you're flying. You certainly don't want to be worried about your airplane when you should be concentrating on actually flying. Soloing is hard enough as you are fighting your own confidence you don't need to have a lack of confidence in your airplane.

I think your instructor, at the very least, needs to know where your head is and either reassure you that your airplane is fine or validate your concern.

 

[FFSchooley]

Fair enough. I will let him know and ask his opinion.

 

[Glen Geller]

Schooley,
I think you live in California, what city and at what airport is your plane based at?
Maybe another member who is not too far away could come over and put a more experienced Shortwing eye on the plane or fly it with you and give an opinion?


As I have mentioned before, this is a closed group and you can put a little relevant info in your profile and signature so your fellow owners are aware of such useful trivia. OK to omit your SSI # or bank PIN.
GG

 

[FFSchooley]

Lol, thanks glen. I though I had but I will make sure to edit it. Yes, I live in CA.

As luck would have it, my instructor just had emergency hand surgery for an injury, so it looks like my solo is delayed anyway.

I know it’s hard to diagnose this stuff via the internet, I guess I am just wondering what’s normal. It doesn’t make it fun to fly when it vibrates soo much. I had dreams of flying across the country in a smooth, comfy plane and enjoying the view. Right now it’s not smooth at all and my hands and feet get numb from the vibration. Although I am sure my death grip on the yoke and pressing the pedals to hard is part to blame.

im nervous that it could be the engine as I think I have tackled everything else. After over $20,000 in repairs, it’s not in the budget anytime soon. Luckily Ly-Con is located about an hour from here so when I do need engine work I can take it to them. I just hope I can fly it for a few years before that happens. If that means vibrating away in the sky, so be it as long as it’s safe enough...

 

[Glen Geller]

Looks like you may be based at Buchanan in Concord, yes?
https://www.airnav.com/airport/KCCR
Anyone flying in to visit you would need to have ADS-B OUT, as you are just inside the 30 mile veil of KSFO.
Pretty flying in that area.

I hope you resolve the vibration problem, it should NOT buzz your hands and feet and be unpleasant at cruise or full power.

GG

 

[J Ryd]

Schooley,
I think you live in California, what city and at what airport is your plane based at?
Maybe another member who is not too far away could come over and put a more experienced Shortwing eye on the plane or fly it with you and give an opinion?


As I have mentioned before, this is a closed group and you can put a little relevant info in your profile and signature so your fellow owners are aware of such useful trivia. OK to omit your SSI # or bank PIN.
GG

That's what I mentioned a while back. Certainly one of our members needs an excuse to fly a mission? Dont make me fly from Denver to CA for a short hop around the pattern. Lol

Jan

 

[FFSchooley]

I would feel horrible if someone flew out here only to tell me it’s normal! My luck it would behave for a guest pilot. But at least someone with some short wing experience could teach me how to land this thing! I’m having a hell of a time and my instructor is still trying to learn this thing too.

Anyways, I guess I will just ignore it and keep plugging along so I can get my ticket and then head to the nearest fly-in!

 

[FFSchooley]

One thing I just realized while talking to Jan, is that the lift strut shakes during climb out under higher load and a high AOA. The vibration during flight is more pronounced during slow flight, slower cruise where I am at lower power settings but have a higher AOA. Not sure if that helps diagnose it or confirms it’s normal.

 

[andya]

Seems like there should be someone in your area that has flow PA-22's before that could take you for a ride around the pattern
I cannot envision an engine vibration that would make the wing strut vibrate like you describe.
Also can think about an aerodynamic situation could do that but if so, that could be worse than an engine vibration.

 

[FFSchooley]

It’s hard for me to really diagnose it because I am trying to learn to fly and figure this out. But as I sit here and think about it, I am realizing it is more pronounced when under load or at higher AOA. Climb out, slow flight, cruising around the pattern. High speed cruise it’s not as bad.

maybe that’s normal for all planes?

 

[sierrasplitter]

Can you video your yokes while you fly to show us the vibration ? Can you video the lift strut vibration ?

My yoke vibrates at 2500 rpm on climb out. Doesnt numb my hand but it does vibrate a bit.

What planes does your instructor usually teach in ? Im sure if He thought it was excessive he would have said so already.

 

[FFSchooley]

I agree, I would think we would have said something. He teaches mostly in a 172.

I just got a go pro as a present, so I will set it up to film the strut and the yoke as best I can.

 

[sierrasplitter]

You can use your phone and post it up to the shortwing facebook page if thats easier

 

[FFSchooley]

Yea, I want to have the camera up for different stages of flight and different RPMs. I will post it on youtube and link it since I don’t have Facebook

 

[gliderman]

hi Brett
just a thought- do you have a oversize cylinder- if one is installed and not matched on the opposing cylinder, vibration will happen. it may or not be marked.....
green for P010
yellow for P020

it also could be stamped on the clyinder base flange

shane-o

 

[FFSchooley]

I will take a look! Thanks for the suggestion. Will report back

 

[Jim]

Hi,

These things can be dynamically balanced. Spinning the prop with the engine running at various RPMs will eliminate or confirm something much better than the guessing going on here. If the shop providing the balance offers a solution you'll be miles ahead of things. Might be as easy a fix as them attaching a small bolt with several washers to your spinner backing plate.

 

[FFSchooley]

Yea, it’s on my to-do list as soon as I get my PPL.

 

[at7615]

Hi,

These things can be dynamically balanced. Spinning the prop with the engine running at various RPMs will eliminate or confirm something much better than the guessing going on here. If the shop providing the balance offers a solution you'll be miles ahead of things. Might be as easy a fix as them attaching a small bolt with several washers to your spinner backing plate.

Have balanced a bunch of props and rotors, I don't get the "dangerous ips" and then do nothing to make it smooth! What do you have to lose to chart the vibration, make an ajustment to verify the clock and then balance it. "A book a cook does not make" All the fancy equipment in the world will do no good if you don't use it! I used a strobex for decades balancing Bell 412's which is the lowest level of hell in Dante's circle! So what is the present "IPS" and "clock"? PLease send it to me and I'll be glad to plot the weight for you! Wish I was close cause I likes a challenge!

Before we begin, double verify that you have no balance bolt/weights on the bulkheads or some nasty repair job that added extra weight or missing nutplates/stands at this time, second what PN flywheel are you running. Third, make sure your prop bolts are torqued to specs. Fourth, get 2 different color chalk and mark the ends of your prop and check that the blades are running together. The game begins!

https://www.rpxtech.com/uploads/9/3/3/2/93321990/dynavibe_classic_user_manual_v1-09.pdf

https://www.rpxtech.com/uploads/9/3/3/2/93321990/polarchart.pdf

 

[FFSchooley]

Ok, will try to tackle all that too.

 

[walt.buskey]

Thanks for the suggestions, everybody. So far, all plugs checked, cleaned & gapped, all plug wires checked, prop's indexing checked --but we'll check it again; prop was sent out for overhaul & re-installed, torqued correctly. Prop shop said I had an older prop but that it was in very good shape.

My A&P's gadget --I'm still learning about this-- apparently hasn't been able to indicate any position for adding weight because it vibrates so much, according to his device. In glancing at it on the floor, I recall seeing in excess of 2 ips before it just went to the "Dangerous Vibration--Reduce to Idle" message.

So as soon as he has time, we'll re-install the right mag and go from there. I'll try to get more details -- check the cylinders, observe where prop stops when engine's shut down, flywheel part #, etc.

at7615, I've saved your attachments to my computer. Don't recall what brand accelerometer my A&P has, but I'll find out.

 

[FFSchooley]

Yes, thanks for all the suggestions and help. I didn’t intend for this tread to become a trouble shooting vibration thread, but now have a few more things to check out, so thanks!

If I could just go back to my original question, until I can get some experience in some other planes, I am still trying to figure out if I need to worry about this stuff soo much or just accept it all as part of owning an old plane? Yes, it’s something I need to try to track down and fix, but if every old plane has some sort of vibration or rattle or shake then I can take a break from worrying so much and just fly. But if that’s not the case and it might be more serious than that, I will take a different frame of mind.

so with that said, do you all have super smooth shake free non-smoking rivet planes, or is it normal to have a vibration here and there, screws and knobs rattling loose on occasion, smoking rivets here and there, etc? I guess I am trying to get some “experience” in other peoples planes virtually until I can actually do it for real.

this is obviously the downside to buying a plane before getting your ticket and having no experience in any other planes, but it’s the choice I made and have to live with it

 

[walt.buskey]

Me, too, same situation. The only thing I have to go on is that darned accelerometer saying it's too rough -- to me, it feels the same as it ever did. But with this plane, and the way it's been taken care of (or not)... that doesn't mean much. Notice on at7615's second DynaVibe attachment above that anything over 1.00 - 1.25 ips is considered "Extreme." See if you can get yours measured, Brett.

I even contacted the guy I bought it from --yes, we're still on good terms-- and he said he never thought much about it, but he felt it did vibrate -- "some." (I should repeat that he was an AF pilot; as such, he trusted all the "fixing" to the A&Ps at his airfield, so I don't fault him for the --apparent-- poor care 57A received.)

Walt

 

[dgapilot]

There are a number of phone apps that can measure vibration and frequency. Almost all vibrations will be engine related, and be a multiple (frequency) of the movement of the part causing the vibration. Use a phone app to record vibration level and frequency, and another phone or camera to show the vibration on the yoke or struts.

Do not ignore vibration! Your airplane is telling you something! Vibration (aside from what is causing it) will result in more wear and tear on the rest of the airframe. Worn bushings, cracked fairings, cracked ribs, fatigue failures of other structural parts. Find out what is causing it and fix it.

The TriPacer I fly had a bad vibration around 2300 rpm. Indexed the prop and it is all but gone now. When I had my Howard, had a vibration that cracked my oil cooler scoop. Did a dynamic balance on the prop and that solved the cracking problem.

All that said, reciprocating powered airplane will have some vibration. Certainly high power, high AoA will result in vibrations based on blade pass frequency, often seen in the fabric on the underside of the wing, and the horizontal stabilizer. Only with considerable flight experience will you know what is “normal” and what isn’t. Find someone with a fair amount of TriPacer time to fly your airplane and evaluate the vibrations. Get a dynamic balance on your engine/prop. If vibration is so bad you can’t dynamically balance, borrow a different prop, try with the spinner and spinner bulkheads off. Make sure the flywheel is in the correct position, verify mag timing, check your induction system and your exhaust system.


Sent from my iPhone using Tapatalk

 

[Troy Hamon]

Either of you have a tripacer pilot come test the plane? The airplanes are light, which makes balancing during a ground run challenging. Without being in your plane, it is hard to evaluate based on the descriptions.

 

[FFSchooley]

Ok, well I need the fly “the vibrator” enough to get my ticket so I can then take it to get dynamic balanced, go to fly ins and meet you all and try other planes, and ultimately fly it to Texas and beg Steve to have a look over this thing. I will try the vibration app as well as film the best I can. My solo is delayed due to my instructor having emergency hand surgery. Always something I tell ya!

should anyone decide they want to come out to california to have a try at flying “the vibrator,” the offer of putting you up at the firehouse and getting to ride along for a shift or two, as well as some ride along time on our rescue helicopter and a trip around the bay still stands to the first taker! Meals included too, especially if you bring a prop balancer!