Engine Red line as a result of Speed Vs Power

James_Dean said:
Yep, and if he spun it to just 2835 he has to -

1. Identify and correct the cause of the overspeed.

2. Complete the “Cylinder Overspeed Inspection” procedure in this Service Bulletin.

3. Drain the lubricating system.

4. Remove oil screens and filters.

5.Examine all screens and filters in the lubrication system for metal contamination. If
any unexplained metal accumulation is found, identify and correct the cause before
returning the engine to service.

6. If the engine has magnetos, complete the “Magneto Overspeed Inspection” procedure
in this Service Bulletin.

7.Complete the “Valve Train Overspeed Inspection” procedure in this Service Bulletin.
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Suit yourself. I've known plenty of Lycomings turned more than "momentarily" well past 10%, hundreds of times, and make TBO. Hope the acro guys don't find out about this very important bulletin. ;-)
 
RoscoeT said:
Suit yourself. I've known plenty of Lycomings turned more than "momentarily" well past 10%, hundreds of times, and make TBO. Hope the acro guys don't find out about this very important bulletin. ;-)
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Is there any reference out there to help me understand which limitations in my POH I have to obey and which ones I can ignore? I was taught you were supposed to observe them.
 
James_Dean said:
Is there any reference out there to help me understand which limitations in my POH I have to obey and which ones I can ignore? I was taught you were supposed to observe them.
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What you "were taught" is a starting point, not an absolute ending point. I say follow your POH. Just don't expect to get much out of a high performance acro plane with a fixed pitch prop unless you deviate from the almighty POH, assuming it even has one. But I can't think of a reason to bomb around in your Cherokee turning 3,000 RPM. This is case where decades of operational experience disagrees with the Lycoming bulletin produced by incentive from lawyers.
 
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RoscoeT said:
What you "were taught" is a starting point, not an absolute ending point.
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I am unaware of any limitations that the FAA allows you to exceed. Where did I miss that handbook.

Tim
 
Most CS props will momentarily overspeed during a go-around. That's pretty common. During a sneak in buzz job, too, but I'm sure nobody here does those!
 
tspear said:
I am unaware of any limitations that the FAA allows you to exceed. Where did I miss that handbook.

Tim
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LOL...now we're conflating engine overspeed with FAA requirements. I'll spread the word to the aerobatic community to cease and desist because an internet guy says they're all in violation of FAA rules.
 
RoscoeT said:
What you "were taught" is a starting point, not an absolute ending point. I say follow your POH. Just don't expect to get much out of a high performance acro plane with a fixed pitch prop unless you deviate from the almighty POH, assuming it even has one. But I can't think of a reason to bomb around in your Cherokee turning 3,000 RPM. This is case where decades of operational experience disagrees with the Lycoming bulletin produced by incentive from lawyers.
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I notice you keep editing your post. Maybe rethinking your sage advice?
 
RoscoeT said:
LOL...now we're conflating engine overspeed with FAA requirements. I'll spread the word to the aerobatic community to cease and desist because an internet guy says they're all in violation of FAA rules.
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Not me. Look at the operating limitations for the plane. In fact, in many planes, there is no limitation in section 6 of the AFM on prop speed.

Tim
 
tspear said:
Not me. Look at the operating limitations for the plane. In fact, in many planes, there is no limitation in section 6 of the AFM on prop speed.
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No kidding. Why did you bring it up?
 
tspear said:
Not me. Look at the operating limitations for the plane. In fact, in many planes, there is no limitation in section 6 of the AFM on prop speed.

Tim
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I see a lot of them in Section 2, though....engine rpm limits, anyway. But in most light airplanes, prop and engine rpm are directly related.
 
RoscoeT said:
The parting shot of someone with no legs to stand on and nothing relevant to say.
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Lolz. You're right. My only relevant contribution is to post the applicable guidance from the manufacturer and to suggest that we follow the limitation sections for our aircraft. Your contribution is to offer up anecdotal stories about people(wearing parachutes) pushing their aircraft and possibly the law to the limit(where is that again?) and use that as justification to say "give 'em hell".

One of us is showing a few of the hazardous attitudes. And it ain't me.
 
Don't forget the prop gets VERY HEAVY with high RPMs.

That is the prop may come apart in an over-speed condition. Not sure about this particular prop, but 2600 RPM with an 88" beech electric is where they say "inspect it". At 3000 RPM they say "throw it away". I've seen some limitations on wooden props (not sure what you have on this Grumman).
 
MauleSkinner said:
Loss of oil pressure to the prop is not necessarily a failed engine. I'd rather be able to make rated power if I still had the engine running.
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If you go to fine pitch you may not be able to make 100% power. You'll be able to make 100% (and more) RPM, and will have to throttle back to prevent overspeeding.
 
Ted DuPuis said:
If you go to fine pitch you may not be able to make 100% power. You'll be able to make 100% (and more) RPM, and will have to throttle back to prevent overspeeding.
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Good point , but probably a lot closer than you'd be on the high pitch stop, especially when you might need it most at Vx/Vy kind of speeds.
 
MauleSkinner said:
Good point , but probably a lot closer than you'd be on the high pitch stop, especially when you might need it most at Vx/Vy kind of speeds.
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I agree. Just wanted to clarify that going to fine pitch won't allow 100% power most of the time when you're moving.

Constant speed props are wonderful things. I'm a fan. :)
 
James_Dean said:
Lolz. You're right. My only relevant contribution is to post the applicable guidance from the manufacturer and to suggest that we follow the limitation sections for our aircraft. Your contribution is to offer up anecdotal stories about people(wearing parachutes) pushing their aircraft and possibly the law to the limit(where is that again?) and use that as justification to say "give 'em hell".

One of us is showing a few of the hazardous attitudes. And it ain't me.
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I get it, you know zilch about aerobatics, its history, Lycoming engines, or aerobatic pilots, and therefore consider my ONE specific point about a Lycoming not needing a dang inspection because it turned 2900 RPM to be a "hazardous attitude". These are not anecdotal "stories". It's SOP in this world. The engines don't blow up. We are not hazardous. The FAA does not give a single damn about the RPM we run. Fact. Carry on.
 
Been a loooooong time since I've looked at the limitations section of a light airplane, but I always understood a redline to be a placard.
In my mind that made it a limitation.
 
Kritchlow said:
Been a loooooong time since I've looked at the limitations section of a light airplane, but I always understood a redline to be a placard.
In my mind that made it a limitation.
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What I really like is that I bought a magic piece of paper that changed all the limits. Suddenly 200 more RPM was fine for the prop when it was an inspection item prior to that piece of paper.

Give me real limits or give me a piece of paper!
- Patrick Henry Jones
 
RoscoeT said:
I get it, you know zilch about aerobatics, its history, Lycoming engines, or aerobatic pilots, and therefore consider my ONE specific point about a Lycoming not needing a dang inspection because it turned 2900 RPM to be a "hazardous attitude". These are not anecdotal "stories". It's SOP in this world. The engines don't blow up. We are not hazardous. The FAA does not give a single damn about the RPM we run. Fact. Carry on.
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Never claimed to. What I do know is that the OP's plane has a limitation in the POH to not exceed 2700 rpm. Those are mandatory observance items for the FAA. The plane has an engine that is covered by an MSB that advises actions in the case of an exceedence, but is not mandatory for pt91.

In this case, I'm right and you're wrong. It isn't ok or legal to let it go past 2700 rpm.

I look at it the same as the ITT limit on my PT-6's. Could I exceed the limitation by 25 degrees safely? Sure. Is it good for the engine and my wallet long term? Hell no. Also not legal.
 
James_Dean said:
Never claimed to. What I do know is that the OP's plane has a limitation in the POH to not exceed 2700 rpm. Those are mandatory observance items for the FAA. The plane has an engine that is covered by an MSB that advises actions in the case of an exceedence, but is not mandatory for pt91.

In this case, I'm right and you're wrong. It isn't ok or legal to let it go past 2700 rpm.

I look at it the same as the ITT limit on my PT-6's. Could I exceed the limitation by 25 degrees safely? Sure. Is it good for the engine and my wallet long term? Hell no. Also not legal.
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You're missing the boat. I'm not trying argue FAA legal theory or to encourage folks in their Cherokees and Cessnas to deviate from their POH and go rattle windows at 3500 RPM. My point was that there is no need to worry about doing a stupid inspection if you happened to turn your Lycoming 2900 RPM more than "momentary". I'm not trying to get the types of people who don't drive 1MPH over the speed limit to do things contrary to their understanding of the FAA regs...a "rule" in this this case which the FAA never has and never will make an issue out of. I'm more concerned about the REALITY of the legal and practical implications of doing certain things. BTW, the FAA has watched me turn my Lycoming well over 3,000 RPM lots of times. But I guess you will pay for an inspection of your Lycoming that accidentally turned 2900 RPM for a little bit. If that makes you feel like a more law-abiding citizen and responsible safe pilot, then I won't fault you.
 
RoscoeT said:
You're missing the boat. I'm not trying argue FAA legal theory or to encourage folks in their Cherokees and Cessnas to deviate from their POH and go rattle windows at 3500 RPM. My point was that there is no need to worry about doing a stupid inspection if you happened to turn your Lycoming 2900 RPM more than "momentary". I'm not trying to get the types of people who don't drive 1MPH over the speed limit to do things contrary to their understanding of the FAA regs...a "rule" in this this case which the FAA never has and never will make an issue out of. I'm more concerned about the REALITY of the legal and practical implications of doing certain things. BTW, the FAA has watched me turn my Lycoming well over 3,000 RPM lots of times. But I guess you will pay for an inspection of your Lycoming that accidentally turned 2900 RPM for a little bit. If that makes you feel like a more law-abiding citizen and responsible safe pilot, then I won't fault you.
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Naturally you don't do much more than compression and timing checks on your annuals, and expect to make TBO.
 
MauleSkinner said:
Naturally you don't do much more than compression and timing checks on your annuals, and expect to make TBO.
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Pretty much. Standard compression pistons (high top end life), flown regularly. Still going strong after 1700 hrs. A few seconds of 3000+ RPM on down lines on each flight really doesn't do as much harm as many tend to think. Again, not advocating anything, just a little perspective.
 
Roscoe, you are a test pilot man, not me, unnecessary risk, I hope it works out for you. Too many pilots are nonchalant about stuff like this which frankly, contributes to the GA accident rate. 3,000 rpm on an engine designed for 2,700 is asking for trouble, stresses on connecting rods, rod ends, bearings, valve trains, you name it increase, probably exponentially. These things are identified as issues by engineers designing and working on these engines, not just lawyers. As I said, I hope it works out for you, may the wind be under your wings. Peace.
 
PaulS said:
Roscoe, you are a test pilot man, not me, unnecessary risk, I hope it works out for you. Too many pilots are nonchalant about stuff like this which frankly, contributes to the GA accident rate. 3,000 rpm on an engine designed for 2,700 is asking for trouble, stresses on connecting rods, rod ends, bearings, valve trains, you name it increase, probably exponentially. These things are identified as issues by engineers designing and working on these engines, not just lawyers. As I said, I hope it works out for you, may the wind be under your wings. Peace.
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I'm on the wrong site. Most pilots live in a much smaller box. I should not have revealed the "secret" that acro pilots have known for the last 45 years about Lycoming engines. My acro buddies who include some of the smartest, most well-educated, calculated, and talented stick and rudder pilots anywhere are not "unnecessary risk" takers. Since most of you here (and very safe to say YOU) have no experience in this arena, I can see how you think it's just cowboy "hazardous attitude". I have years of experience operating in this arena. You do not. You are simply pontificating. I'm relaying reality. Sorry if that disagrees with what you "were taught" or what you think. So support your local A&P and tear apart your Lycoming if you ever see 2,900 RPM on the tach. ;-)
 
RoscoeT said:
I get it, you know zilch about aerobatics, its history, Lycoming engines, or aerobatic pilots, and therefore consider my ONE specific point about a Lycoming not needing a dang inspection because it turned 2900 RPM to be a "hazardous attitude". These are not anecdotal "stories". It's SOP in this world. The engines don't blow up. We are not hazardous. The FAA does not give a single damn about the RPM we run. Fact. Carry on.
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The thing is that even though you may be correct your comment is not applicable to this thread. The op is flying a four place family hauler that he uses to fly his very precious family around. Who gives a **** what some airshow performer or competitive aerobatics pilot does to their engine. He should stay within the engine limitations as published.
 
RoscoeT said:
I'm on the wrong site. Most pilots live in a much smaller box. I should not have revealed the "secret" that acro pilots have known for the last 45 years about Lycoming engines. My acro buddies who include some of the smartest, most well-educated, calculated, and talented stick and rudder pilots anywhere are not "unnecessary risk" takers. Since most of you here (and very safe to say YOU) have no experience in this arena, I can see how you think it's just cowboy "hazardous attitude". I have years of experience operating in this arena. You do not. You are simply pontificating. I'm relaying reality. Sorry if that disagrees with what you "were taught" or what you think. So support your local A&P and tear apart your Lycoming if you ever see 2,900 RPM on the tach. ;-)
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I would be willing to bet those pilots you are talking about don't turn the engines on their crosscoutry family airplanes like they do in the competition aircraft. Your comments are not applicable to the op's situation.
 
Tarheelpilot said:
The thing is that even though you may be correct your comment is not applicable to this thread. The op is flying a four place family hauler that he uses to fly his very precious family around. Who gives a **** what some airshow performer or competitive aerobatics pilot does to their engine. He should stay within the engine limitations as published.
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You guys must deliberately miss the target for internet argument's sake. Let me sum up in hopefully simple enough terms........

If you happen to accidentally turn your Lycoming 2900 RPM in your "family hauler" for more than what Lycoming defines as "momentary", don't freakin' worry about it.

OR......you can point to where I advocate "family hauler" pilots deliberately overspeeding their engine. And not a problem, BTW, just pointless.

I imagine the POA indignant will not rest over this. LOL
 
Hey @SixPapaCharlie ...

Lots of stuff up there in the thread. Good info.

But the answer to your question is easier than all of it.

Would you downshift your car on a hill to an RPM above redline for compression braking?

No.

So don't do it to the airplane either. :)

Pull the black knob back if it's overspeeding in the descent.
 
Remember when discussing things meant sharing other people's experiences and perspectives? WTF is with this site and the guys that just want to ague for arguing's sake? Take your meds.

Simple question. How many of you fixed pitch owners have checked your tachs with a an optical tach lately? If you haven't? There's a good chance you're overspeeding your engine on a regular basis. Ignorance is bliss. Just sayin'.
 
Stewartb said:
Simple question. How many of you fixed pitch owners have checked your tachs with a an optical tach lately? If you haven't? There's a good chance you're overspeeding your engine on a regular basis. Ignorance is bliss. Just sayin'.
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Isn't just the fixed pitch that needs checked from time to time.

Shall we mention the sodium light 60 Hz trick again for checking tach numbers? :)
 
RoscoeT said:
You guys must deliberately miss the target for internet argument's sake. Let me sum up in hopefully simple enough terms........

If you happen to accidentally turn your Lycoming 2900 RPM in your "family hauler" for more than what Lycoming defines as "momentary", don't freakin' worry about it.

OR......you can point to where I advocate "family hauler" pilots deliberately overspeeding their engine. And not a problem, BTW, just pointless.

I imagine the POA indignant will not rest over this. LOL
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I'm not being indignant. I'm not arguing just for the fun of it. I hate arguing.

What you have said and the way you have framed your statements is inappropriate for the conversation being held in this thread.
 
Salty said:
Don't forget about lubrication. The faster those parts are spinning, the more lubrication you need, even in a decent you may not be getting enough of that slippery stuff everywhere it needs to be if you spin it too fast.
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I can't believe eman, sac, or mscard hasn't run with this post yet...
 
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