Cessna 172M 10,000 hours+

1

172M

Filing Flight Plan
Joined
Aug 29, 2020
Messages
7
Display Name
Display name:
Carl
Hi everyone,
I have a few questions regarding a Cessna 172M. I've put over 10K hours on my 172 and it has developed a vibration that I'm having trouble finding the cause. Do the fuselages wear out? What to look for? Something in the firewall letting go? Most of the vibration is in the rudder pedals.
More info about the 172 is 180hp conversion, converted to a taildragger (Bolen kit), has been wrecked and is why it was converted to a taildragger. Always hangered. Rebuilt wings 4 or 5 years ago.
What determines when the 172 would be wore out? Corrosion? Fatigue?
Any help with ideas and where to look would be great.
Thanks,
 
10,000hrs is nothing for a Cessna 100 series aircraft if it’s been properly maintained. The school 172’s at my local airport usually have 10-20k on their airframes (M,N and P models) and I’ve seen a 172 for sale that had over 30k.

If I were you I’d look at when the last propeller balance was completed, worn or cracked engine mounts and the bolts that connect the engine mount to the airframe.
 
Propeller balancing done well has amazing results. We had it done to the club Skylane a few years ago and came back a much quieter and smoother machine.
 
172M said:
Hi everyone,
I have a few questions regarding a Cessna 172M. I've put over 10K hours on my 172 and it has developed a vibration that I'm having trouble finding the cause. Do the fuselages wear out? What to look for? Something in the firewall letting go? Most of the vibration is in the rudder pedals.
More info about the 172 is 180hp conversion, converted to a taildragger (Bolen kit), has been wrecked and is why it was converted to a taildragger. Always hangered. Rebuilt wings 4 or 5 years ago.
What determines when the 172 would be wore out? Corrosion? Fatigue?
Any help with ideas and where to look would be great.
Thanks,
Click to expand...

You need to be a bit more specific as you try to diagnose. For example does the vibration frequency or amplitude you feel in the rudder pedals vary with different engine speeds? Does it vary with different airspeeds? Climb vs descent? And so forth. You won't likely trace it quickly and efficiently if you don't try to isolate the likely source(s) first.


AggieMike88 said:
Propeller balancing done well has amazing results. We had it done to the club Skylane a few years ago and came back a much quieter and smoother machine.
Click to expand...

Agree with this completely.

But props rarely go out of balance suddenly. I am presuming the OP's vibration problem is a recent, significant step function onset. Which implies something has changed. That is why I would suggest some diagnostics and inspection before undertaking any balancing actions.
 
GRG55 said:
You need to be a bit more specific as you try to diagnose. For example does the vibration frequency or amplitude you feel in the rudder pedals vary with different engine speeds? Yes Does it vary with different airspeeds? Yes Climb vs descent? Both And so forth. You won't likely trace it quickly and efficiently if you don't try to isolate the likely source(s) first.




Agree with this completely.

But props rarely go out of balance suddenly. I am presuming the OP's vibration problem is a recent, significant step function onset. Which implies something has changed. That is why I would suggest some diagnostics and inspection before undertaking any balancing actions.
Click to expand...
Had the dynamic balancing done twice. No difference.

Frequency is in tune with the engine RPM's. One thing is it's fairly smooth with the cowl off. Put the cowl on and I feel way more vibration. Can't fly it with no cowl so? But I have examined every millimeter of the cowl for rubbing or metal to metal contact and there is none. It does seem to bang a little if I grab the cowl and force it into the fuselage. But why all of a sudden would it get loose? Changed a few of the Lord mounts and no difference.
 
GLDP said:
10,000hrs is nothing for a Cessna 100 series aircraft if it’s been properly maintained. The school 172’s at my local airport usually have 10-20k on their airframes (M,N and P models) and I’ve seen a 172 for sale that had over 30k.

If I were you I’d look at when the last propeller balance was completed, worn or cracked engine mounts and the bolts that connect the engine mount to the airframe.
Click to expand...
Prop was done about 6 years ago. Has some wear and corrosion. New Barry control mounts and no change.
 
GLDP said:
10,000hrs is nothing for a Cessna 100 series aircraft if it’s been properly maintained. The school 172’s at my local airport usually have 10-20k on their airframes (M,N and P models) and I’ve seen a 172 for sale that had over 30k.

If I were you I’d look at when the last propeller balance was completed, worn or cracked engine mounts and the bolts that connect the engine mount to the airframe.
Click to expand...
Also nice to know about the hours on the airframe. Thanks
 
Look closely at engine mount. Could be a fatigued/cracked weld.
 
Like others have said........10,000 is just a little kid compared to the 207's in Alaska. Most of them have 50,000 hrs.

Every 10K, though, you should perform the Cessna 10k single-engine continued airworthiness maintenance program, available from your Cessna dealer.
 
172M said:
Hi everyone,
I have a few questions regarding a Cessna 172M. I've put over 10K hours on my 172 and it has developed a vibration that I'm having trouble finding the cause. Do the fuselages wear out? What to look for? Something in the firewall letting go? Most of the vibration is in the rudder pedals.
More info about the 172 is 180hp conversion, converted to a taildragger (Bolen kit), has been wrecked and is why it was converted to a taildragger. Always hangered. Rebuilt wings 4 or 5 years ago.
What determines when the 172 would be wore out? Corrosion? Fatigue?
Any help with ideas and where to look would be great.
Thanks,
Click to expand...
Place the fuselage in a cradle and check for looseness of the tail, and cable assemblies
 
kgruber said:
Like others have said........10,000 is just a little kid compared to the 207's in Alaska. Most of them have 50,000 hrs.

Every 10K, though, you should perform the Cessna 10k single-engine continued airworthiness maintenance program, available from your Cessna dealer.
Click to expand...
Thanks
 
Cessna claims the air frames time-out about 30K hours, maybe 32K hours. Cessna published a service bulletin on this topic.
 
NordicDave said:
Cessna claims the air frames time-out about 30K hours, maybe 32K hours. Cessna published a service bulletin on this topic.
Click to expand...

Makes me think the true number is more like 60k then.... lawyers ya know.
 
You must log in or register to reply here.
Back
Top