High RPM (2,900-3,000) After Take Off

[Skates97]

I had something new happen on my flight back from Arizona Sunday. Everything was normal on take off, I confirmed 2,700 RPM as I began the roll, and then just after we left the ground it sounded and felt different so I looked over at the tach and it was between 2,900-3,000. The sound was actually different enough than normal that my wife even noticed it. I quickly turned the prop knob and brought it back down to 2,700. Tonight I went out to get in some night landings (my night currency would expire 11/14). It did the same thing to me, 2,700 on the roll but after leaving the ground surging up to about 2,900. Again I dialed it back and just left the prop set there as I was only doing pattern work.

Ideas? The only thing that was done to the plane is I changed the oil and went from running Phillips Victory 100 to Phillips XC 20/50 (plus Avblend) for the winter as we will be travelling to Utah this winter. I can't imagine that the oil would make a difference. When I bought the plane it was running Aeroshell 15/50 and I never saw anything over 2,700 rpm.

[carusoam]

Wait right there....

Sounds like the governor has gone off line...

There are a few different causes for that.

Search for overspeed limitations to see what might be required.  There is a limit of how fast for how long and what needs to be done...

You have time to look up the newest governor’s for your plane PCU2000 comes to mind.  Cost vs OH cost are similar...

I OHd My C's gov, to find that the seal in my crank shaft came loose, internally leaking all the oilP That was going to the prop...

Could be prop actuators...

Could be governor....

Could Be shaft seal, a small piece of aluminum hammered into the shaft, up by the prop.

Flying it without fixing it won't work very well... the prop will overspeed before developing full power.  A T/O at less than full power can take a lot of runway...

Stuff I learned from my M20C... I should have named it 'the professor' ... 

Not trying to be an alarmist, but reading the Lycoming doc about overspeed can be alarming....

Getting the seal reseated, took removing the prop...

Got any oil leaks?

PP thoughts only, not a mechanic...

Best regards and good luck,

-a-

 

 

[Skates97]

Nope, no oil leaks... 

It's going in the shop for the EDM 830 to be installed on Monday. I'll have to have them check it out. 

[carusoam]

It’s probably a good sign that you were able to turn it down to 2700 rpm.  That's a hint the gov is working. But something let it lose it's set-point...?

Get a good look at its control cable ends.  Any fraying, or the end coming off....

Any odd feeling when using the prop control?

Some prop control cables have given MSers a bad day...

Best regards,

-a-

[Guitarmaster]

I had something new happen on my flight back from Arizona Sunday. Everything was normal on take off, I confirmed 2,700 RPM as I began the roll, and then just after we left the ground it sounded and felt different so I looked over at the tach and it was between 2,900-3,000. The sound was actually different enough than normal that my wife even noticed it. I quickly turned the prop knob and brought it back down to 2,700. Tonight I went out to get in some night landings (my night currency would expire 11/14). It did the same thing to me, 2,700 on the roll but after leaving the ground surging up to about 2,900. Again I dialed it back and just left the prop set there as I was only doing pattern work.
Ideas? The only thing that was done to the plane is I changed the oil and went from running Phillips Victory 100 to Phillips XC 20/50 (plus Avblend) for the winter as we will be travelling to Utah this winter. I can't imagine that the oil would make a difference. When I bought the plane it was running Aeroshell 15/50 and I never saw anything over 2,700 rpm.

What is your oil pressure reading when the event occurs?


Sent from my XT1585 using Tapatalk

[N601RX]

Although not mandatory Lycoming SB369 covers overspend events.   Prop manufacturer also has additional guidance  

https://www.lycoming.com/sites/default/files/SB369N Engine Inspection after Overspeed .pdf

3. In

the case where the overspeed is 10% or more, the corrective action is to:

1. Remove the engine from the aircraft.

2. Disassemble the engine in accordance with the applicable Lycoming Overhaul Manual.

3. Examine the engine and components in accordance with the applicable Lycoming Overhaul Manual.

4. Replace any parts that are damaged or not in agreement with the latest revision of the Table of Limits SSP-1776.

5. In engines with dynamic counterweights, replace the bushings in the counterweight and the crankshaft.

6. In the engine logbook, record the overspeed incident, any inspections, and corrective action. 

Edited November 9, 2017 by N601RX

[Mooneymite]

Something is very wrong.

Even if the prop governor completely failed the internal stops in the prop should have prevented that extreme an overspeed.

This engine/prop needed professional attention the first time it happened.  The subsequent flight should not have been attempted without a repair.

3000 rpm?  Wow!

[MIm20c]

3k rpm is really high!  I would be careful flying again like that. It would be one thing pushing 2750 for a few seconds while you figure things out but you are considerably higher than that. I agree with @Mooneymite that the propeller pitch hard stop should have stepped in. 

I’m not sure how mechanically inclined your wife is but when mine mentions something wrong with the car I run out to the driveway and check to see if all four wheels are attached or if the engine is dragging on the ground.

[mpg]

get a rpm test done to confirm your tach reading!!

compare that tach reading to your exact memory of the rpm you saw!!

dredge your memory for the exact amount of time that you ran at that maximum overspeed!!

study sb 369!    http://davidduffer.com/lycoming/Lycoming_SB_SL/sb/SB369.pdf

[N601RX]

6 minutes ago, mpg said:

get a rpm test done to confirm your tach reading!!

compare that tach reading to your exact memory of the rpm you saw!!

dredge your memory for the exact amount of time that you ran at that maximum overspeed!!

study sb 369!    http://davidduffer.com/lycoming/Lycoming_SB_SL/sb/SB369.pdf

This link is to a version that is several version old. The current version is in my post above. 

[Bob_Belville]

Since both you and your wife heard/felt something was wrong I would not think that it is only a tach problem. I hope you're hearing the alarm in the replies above. There is at least a very real possibility that the engine has sustained damage. 

[Skates97]

6 hours ago, carusoam said:

It’s probably a good sign that you were able to turn it down to 2700 rpm.  That's a hint the gov is working. But something let it lose it's set-point...?

Get a good look at its control cable ends.  Any fraying, or the end coming off....

Any odd feeling when using the prop control?

Some prop control cables have given MSers a bad day...

Best regards,

-a-

Prop Control felt normal. Checking the cable afterwards showed no signs of anything amiss. RPM responded immediately when I adjusted it, brought it back to 2,700, then 2,600 for the remainder of the climb and 2,400 once at altitude.  Subsequent flight (three trips around the pattern) I was watching for it and caught it before it got to 2,800 adjusting the prop control for 2,700 and leaving it there. On the two take offs following that it never went past 2,700 where the cable was set at.

3 hours ago, Guitarmaster said:

What is your oil pressure reading when the event occurs?


Sent from my XT1585 using Tapatalk
 

I couldn't tell you what the reading was when it occurred as my first action was to adjust the prop control. I can say oil pressure was normal on the take off roll and normal for the duration of the flight, but in that moment I don't know. In run-up oil pressure was fine and when cycling the prop oil pressure dropped as it should, I adjust the prop and watch the oil pressure for a drop. Once it drops I push the control back in which usually results in a drop of 1-200 rpm.

Oil consumption five hours in is less than a quart which is consistent with my records after my previous three oil changes.

26 minutes ago, mpg said:

get a rpm test done to confirm your tach reading!!

compare that tach reading to your exact memory of the rpm you saw!!

dredge your memory for the exact amount of time that you ran at that maximum overspeed!!

study sb 369!    http://davidduffer.com/lycoming/Lycoming_SB_SL/sb/SB369.pdf

The tach is possibly off. Months ago I was checking it with one of the cheap handheld readers and it consistently said it was a 2,640-2,650 when the tach showed 2,700. Of course that could mean it was a cheap instrument doing the reading that was off instead of the tach.

1 hour ago, Mooneymite said:

Something is very wrong.

Even if the prop governor completely failed the internal stops in the prop should have prevented that extreme an overspeed.

This engine/prop needed professional attention the first time it happened.  The subsequent flight should not have been attempted without a repair.

3000 rpm?  Wow!

I don't know if it was exactly 3,000. As I stated in a different thread, eye witness accounts are notoriously unreliable. My memory of the event is that just after lifting off, the engine sounded and felt different. The first thing I looked at was the tach because the engine sounded fast. It was above the red line so I grabbed the prop control and adjusted it. Was it between 2,800-2,900 or between 2,900-3,000? I really can't say with any certainty.

I will post what the mechanic finds.

[Skates97]

38 minutes ago, Bob_Belville said:

Since both you and your wife heard/felt something was wrong I would not think that it is only a tach problem. I hope you're hearing the alarm in the replies above. There is at least a very real possibility that the engine has sustained damage. 

I agree it is not a tach problem. I have enough time in the plane that I know what it sounds and feels like at 2,700 rpm and this was faster.

[MB65E]

Did the high pitch stop fall out since the last flight or maybe it loosened? 

The first thing that gets damaged from high rpm is the mags. For a warm and fuzzy, a lot of the Airshow guys run their io540s between 2900-3100. Makes for some great noise!! My only issue with 3k rpm is that it trashes the mags and puts more ware on the engine. Being certified- you'll need to take Lycomings guidance. 

-Matt

[N601RX]

Keep in mind that the  pitch stop is specified by the type cert and is spec to a value that will allow the engine to reach full rpm under various conditions. At a high altitude airport or on a hot day it should still allow the prop to flatten out enough to reach full rpm.   However at a low altitude airport or cold day when the engine has more available power it will also allow an over speed event. It's the governors job to regulate prop speed, not the stop.   The stop should prevent the prop from going so flat that it can't prevent the prop from producing enough thrust to continue a flight if the gov fails. 

Edited November 9, 2017 by N601RX

[Mooneymite]

1 hour ago, N601RX said:

Keep in mind that the  pitch stop is specified by the type cert and is spec to a value that will allow the engine to reach full rpm under various conditions.

The prop involved has not been specified.  However, on my C, the Hartzel book has very specific guidance on how the pitch stop is to be adjusted.  If this is the same prop, something is definitely out of rig.

[N601RX]

13 minutes ago, Mooneymite said:

The prop involved has not been specified.  However, on my C, the Hartzel book has very specific guidance on how the pitch stop is to be adjusted.  If this is the same prop, something is definitely out of rig.

I don't dispute that they can be adjusted but the type cert gives the number and range for the stock Hartzell.  Perhaps some of the stc props allow more adjustment?

 

Propeller and Propeller Accessories:

1. .... Hartzell constant speed propeller installation

1. (a)  Hartzell HC-C2YK-1 or HC-C2YR-1 hub, 7666-2 blades ..................................

   See Notes 5 and 7.
   Pitch setting at 30.0 in. sta.:

   Low 13.0 ± 0° See Note 6.

   High 29.0° ± 2° Diameter: Max. 74 in.

   Min. allowable for repairs 72.5 in. No further reduction permitted.

2. (b)  Spinner assembly, Hartzell, 835-20 ..................................................................... (835-33 for S/N 69-0001 & ON)

3. (c)  Propeller governor
   Hartzell D-1 -4 or D-1 -6 or H-1 or H-1 L ...........................................................

4. (d)  Propeller governor, Edo Aire 34828014 ..............................................................

5. (e)  Propeller governor, McCauley, C 290D5/T24 .....................................................

2. .... McCauley constant speed propeller installation

1. (a)  Propeller, McCauley, 2D34C53-A hub, 74E-0 blades .........................................

   Pitch settings at 30.0 in. sta.: Low 12.7° ± 2°
   High 27.5° ± 0.5°

   Diameter: Max. 74 in.
   Minimum allowable for repairs 72.5 in.

   No further reduction permitted.

2. (b)  Spinner dome, McCauley, D-2808, D-3148 bulkhead and

   fillet assembly .....................................................................................................

3. (c)  Propeller governor, Woodward 210452 ...............................................................

4. (d)  Propeller governor, EDO Aire, 34828014 ...........................................................

3. .... Hartzell constant speed propeller installation
(a) Propeller, Hartzell HC-C2YK-1 B hub 7666A-2 blades......................................

See Notes 5 and 7.
Pitch settings at 30.0 in. sta.:

Low 13.0° ± 0° (See Note 6.)

High 29.0° ± 2° Diameter: Maximum 74 in.

Minimum allowable for repairs 72.5 in. No further reduction permitted. 

[Skates97]

24 minutes ago, Mooneymite said:

The prop involved has not been specified.  However, on my C, the Hartzel book has very specific guidance on how the pitch stop is to be adjusted.  If this is the same prop, something is definitely out of rig.

The prop is a Hartzell, Model #HC-C2YK-1BF/F7666A-2. I haven't looked in the prop manual regarding this but will be supplying the manual to my mechanic when I get the plane to him.

Hub: S/N CH41645B

It was also desludged back in 2007 after a prop strike a couple owners ago as part of the engine removal/tear down following the prop strike.

[N201MKTurbo]

On my old M20F I once lost most of my oil and the governor stopped working. The engine went to about 3000 RPM. It will get your attention. I think that is about where it goes with the propeller set up correctly. This was at about 11000 Ft.

You said it surged to 3000 RPM. you mean it didn't gradually increase as your speed increased, it just suddenly went high?

[Guest]

It sounds like a very expensive visit to an engine shop, and propeller shop are in your future.

Clarence

[Skates97]

1 minute ago, N201MKTurbo said:

On my old M20F I once lost most of my oil and the governor stopped working. The engine went to about 3000 RPM. It will get your attention. I think that is about where it goes with the propeller set up correctly. This was at about 11000 Ft.

You said it surged to 3000 RPM. you mean it didn't gradually increase as your speed increased, it just suddenly went high?

Honestly tough to tell and surge I suppose is a relative term. Sunday take off roll was normal, 2,700 rpm, off the ground at about 75 mph, and shortly after that I noticed the sound of higher RPM's, looked over and adjusted the prop. Last night I was watching for it and after leaving the ground saw that it was increasing past 2,700 so dialed it back. If that is a surge or gradual increase, I don't know.

Not an issue of oil loss, I put 7 quarts in at the oil change and five hours later I still show over 6 on the dipstick. I'm normally adding a quart about 7.5-8 hours when it is between 5.5-6 quarts before the next flight.

[Guest]

18 minutes ago, N601RX said:

I don't dispute that they can be adjusted but the type cert gives the number and range for the stock Hartzell.  Perhaps some of the stc props allow more adjustment?

 

Propeller and Propeller Accessories:

1. .... Hartzell constant speed propeller installation

1. (a)  Hartzell HC-C2YK-1 or HC-C2YR-1 hub, 7666-2 blades ..................................

   See Notes 5 and 7.
   Pitch setting at 30.0 in. sta.:

   Low 13.0 ± 0° See Note 6.

   High 29.0° ± 2° Diameter: Max. 74 in.

   Min. allowable for repairs 72.5 in. No further reduction permitted.

2. (b)  Spinner assembly, Hartzell, 835-20 ..................................................................... (835-33 for S/N 69-0001 & ON)

3. (c)  Propeller governor
   Hartzell D-1 -4 or D-1 -6 or H-1 or H-1 L ...........................................................

4. (d)  Propeller governor, Edo Aire 34828014 ..............................................................

5. (e)  Propeller governor, McCauley, C 290D5/T24 .....................................................

2. .... McCauley constant speed propeller installation

1. (a)  Propeller, McCauley, 2D34C53-A hub, 74E-0 blades .........................................

   Pitch settings at 30.0 in. sta.: Low 12.7° ± 2°
   High 27.5° ± 0.5°

   Diameter: Max. 74 in.
   Minimum allowable for repairs 72.5 in.

   No further reduction permitted.

2. (b)  Spinner dome, McCauley, D-2808, D-3148 bulkhead and

   fillet assembly .....................................................................................................

3. (c)  Propeller governor, Woodward 210452 ...............................................................

4. (d)  Propeller governor, EDO Aire, 34828014 ...........................................................

3. .... Hartzell constant speed propeller installation
(a) Propeller, Hartzell HC-C2YK-1 B hub 7666A-2 blades......................................

See Notes 5 and 7.
Pitch settings at 30.0 in. sta.:

Low 13.0° ± 0° (See Note 6.)

High 29.0° ± 2° Diameter: Maximum 74 in.

Minimum allowable for repairs 72.5 in. No further reduction permitted. 

Tweaking the propeller fine pitch blade stop to get rated static RPM is allowed in the Hartzell manual and is not unusual.

Clarence

 

[MB65E]

I was referring to the govoner adjustment screw changing and not the propeller stop itself. Sorry for the mix up.  With out counter weights, the prop will do whatever it wants if not limited by oil P.

Personally, I would pull the mags for overhaul. Never hurts, probably close to a 500hr anyway. Then do the normal inspection for a 10% over speed. But check your Tach readings. My tach orgional from '65- reads high by 150rpm when compared to my electronic eye. Finally, depending on if the govoner screw backed out or not, I'd upgrade to the PCU-5000 gov. 

My free opinion only, 

-Matt

[mpg]

31 minutes ago, Skates97 said:

Honestly tough to tell and surge I suppose is a relative term. Sunday take off roll was normal, 2,700 rpm, off the ground at about 75 mph, and shortly after that I noticed the sound of higher RPM's, looked over and adjusted the prop. Last night I was watching for it and after leaving the ground saw that it was increasing past 2,700 so dialed it back. If that is a surge or gradual increase, I don't know.

Not an issue of oil loss, I put 7 quarts in at the oil change and five hours later I still show over 6 on the dipstick. I'm normally adding a quart about 7.5-8 hours when it is between 5.5-6 quarts before the next flight.

here is what i think i know,,,

neither overspeed was for sure 3000 rpm,,, your tach over reads by 50 rpm,, sooo

true rpm was 2950 max,,,   that is Less than 10% overspeed!!

the 1st time was a surprise, but you were ready for the 2nd time,,

you were in take off mode and i would bet your right hand was still on the engine controls,

if the surge was obvious,,, and you noticed Right Now!!

you could have easily and instinctively reduced power or propeller speed Within 3 seconds!!! 

Read the SB,,   you very well could be in the all clear..

still need to correct what made it happen..

[Skates97]

49 minutes ago, MB65E said:

I was referring to the govoner adjustment screw changing and not the propeller stop itself. Sorry for the mix up.  With out counter weights, the prop will do whatever it wants if not limited by oil P.

Personally, I would pull the mags for overhaul. Never hurts, probably close to a 500hr anyway. Then do the normal inspection for a 10% over speed. But check your Tach readings. My tach orgional from '65- reads high by 150rpm when compared to my electronic eye. Finally, depending on if the govoner screw backed out or not, I'd upgrade to the PCU-5000 gov. 

My free opinion only, 

-Matt

500 hour mag inspection was done 28.45 hours ago. I talked with my shop this morning and on Monday they are going strobe it to check the tach readings and will go from there.

It was already going in for the 830 install. (Would have been nice to have had that done a week ago so I could pull the data instead of guessing at numbers but the 13th was the soonest they could get to it.)