Just experienced an emergency...

Armageddon Aviator

Armageddon Aviator

Cleared for Takeoff
Joined
Mar 28, 2006
Messages
1,073
Location
Israel
Display Name
Display name:
Alon Smolarski
Right after take off, at about 300ft, we experienced a partial loss of power accompanied by strong vibrations.

The engine was still producing enough power to climb at about 200ft/min so I decided to keep climbing.

I declared an emergency and warned the other aircraft in the pattern.

At 900ft, I turned back towards the runway, I was too high and too close so I completely closed the throttle, opened full flaps and performed some S-turns to get rid of the excess altitude.

The landing was uneventful.

I guess I was lucky that this thing happened in the pattern...

I need to thank the Almighty and my instructors....

Alon
 
Very glad to hear you are okay, Alon.

I'll save my question until after you say type aircraft and engine. Say type and engine.

Any diagnosis yet?
 
Richard said:
Very glad to hear you are okay, Alon.

I'll save my question until after you say type aircraft and engine. Say type and engine.

Any diagnosis yet?
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The aircraft is a C-172 N - the engine ? some kind of Lycoming...not too sure which model...:dunno:
 
TMetzinger said:
Good job on handling the issue. Please pass along the post-failure analysis.
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The Chief Investigator of the ICAA ( Israeli Civil Aviation Administration ) has been notified as required by our regulations.

The aircraft will be thoroughly inspected next week - I'll keep you posted as soon as I get the results of the inquiry.

I am trying to draw some conclusions about the whole experience - Would I do anything differently ?

Right now, I can't come up with any smart insights - I just acted out of instinct...
 
Whew glad it worked out well! Good work on keeping cool I'd imagine that is 80 percent of the battle. The fact that it was instinct is testament to your preparedness.
 
In Israel the government has to be officially notified over a rough running engine?!? wow....

denny-o
 
Dr. O said:
In Israel the government has to be officially notified over a rough running engine?!? wow....

denny-o
Click to expand...

The "Big Brother" has to know everything !

Once you declare an emergency - there's no way around it, you must report the event to the CAA
 
In my opinion, you did just fine. Unless you skipped a step in preflight that would have allowed you to detect the problem before launching, I can't think of anything you could have done better.

You kept flying the airplane, you kept using the power the engine was producing, you landed safely.

If anyone gives you any BS about abusing the engine by making it continue to run while it was rough, smack them and tell them the whole point of the airplane and engine is to get you back to ground safely, even if they are sacrificed to do so. (Yes, I actually once heard someone tell a pilot that he should have shut the engine down and glided when it began to run rough. This is only good advice if you think there's a fire).
 
Dr. O said:
In Israel the government has to be officially notified over a rough running engine?!? wow....
Click to expand...
If more stuff like that got reported here via things like the Service Difficulty Report (SDR) system, we'd have a lot more data on which to make better decisions about maintenance, and could improve reliability -- which in turn improves safety.
 
TMetzinger said:
In my opinion, you did just fine. Unless you skipped a step in preflight that would have allowed you to detect the problem before launching, I can't think of anything you could have done better.

You kept flying the airplane, you kept using the power the engine was producing, you landed safely.

If anyone gives you any BS about abusing the engine by making it continue to run while it was rough, smack them and tell them the whole point of the airplane and engine is to get you back to ground safely, even if they are sacrificed to do so. (Yes, I actually once heard someone tell a pilot that he should have shut the engine down and glided when it began to run rough. This is only good advice if you think there's a fire).
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Depending on how severe the vibration, it could be a prop issue. Wouldn't you want to shut down in that case, for fear of ripping the powerplant from the firewall? That'll do wonders for your W&B calculations.
 
dennyleeb said:
a lycoming in a older cessna are you sure?
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The 172N has a Lycoming O-320-H2AD in in it. Cessna started using Lycomings in 172s in 1968. The 172N is 1977-1980.

Stuck or broken valve, I'd guess.

Dan
 
Jaybird180 said:
Depending on how severe the vibration, it could be a prop issue. Wouldn't you want to shut down in that case, for fear of ripping the powerplant from the firewall? That'll do wonders for your W&B calculations.
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Good thought!

I wonder if one could tell the difference between a "rough/failing" engine and a horribly unbalanced prop. I'm glad I haven't experienced either.
 
Dan Thomas said:
The 172N has a Lycoming O-320-H2AD in in it. Cessna started using Lycomings in 172s in 1968. The 172N is 1977-1980.

Stuck or broken valve, I'd guess.

Dan
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huh, learn something every day

but the older 182's are conti's right? maybe I just assumed they used em in both

either way glad your safe
 
dennyleeb said:
huh, learn something every day

but the older 182's are conti's right? maybe I just assumed they used em in both

either way glad your safe
Click to expand...

The older 172s are conti's also. O-300. They switched in '68.
 
Having experienced a seriously stuck valve lately in the 152 I'd guess that too since there was vibration involved. It'll be interesting to see what it turns out to be. And it's interesting that it's just been replaced.

Good on you Alon for flying the plane and landing safely.
 
TMetzinger said:
Good thought!

I wonder if one could tell the difference between a "rough/failing" engine and a horribly unbalanced prop. I'm glad I haven't experienced either.
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Aside from FOD, what would cause a prop to become unbalanced enroute?
 
GeorgeC said:
Aside from FOD, what would cause a prop to become unbalanced enroute?
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internal materials failure.... but really, what difference does it make?
Jaybird's right that a prop that sheds a blade or a significant amount of mass could rip the engine right off the airplane, which could render the airplane unrecoverable.

I'd like to think that an event like that might be over very quickly, or discernible from a busted cylinder or other problem, so that the pilot could make an informed decision whether it's necessary to shut down the engine.
 
I was told to shut down the engine and stand the airplane vertical in attempt to get the prop stopped. If successful then its just standard engine out procedures .... after the stall recorvery:hairraise:
 
I believe that the 172N with the Lycoming 0-320-H2AD has been known for valve troubles. Wonder if that was related to this particular issue? The D2J engine came next and the problem was addressed.
 
cbmontgo said:
I believe that the 172N with the Lycoming 0-320-H2AD has been known for valve troubles. Wonder if that was related to this particular issue? The D2J engine came next and the problem was addressed.
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This particular aircraft ( 4X-CHC ) belongs to the Megiddo Aviation FBO.

They must have changed the engine at least 4 times in the past 10 years...so I'd be very surprised if the engine was a 0-320-H2AD
 
GeorgeC said:
Aside from FOD, what would cause a prop to become unbalanced enroute?
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There were a couple early T-18's lost (all fatal) when cut down metal props broke due to fatigue - the shorter props resonated at normal operating speeds and after a relatively few number of hours, a blade would break off. That took the engine off the firewall, and that was the end.
 
Armageddon Aviator said:
This particular aircraft ( 4X-CHC ) belongs to the Megiddo Aviation FBO.

They must have changed the engine at least 4 times in the past 10 years...so I'd be very surprised if the engine was a 0-320-H2AD
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They can't change the engine model unless they have an STC to do that. And then they usually install 180 hp anyway. The Type Certificate for a 172N specifies the O-320-H2AD and that's likely what it is.

Dan
 
TMetzinger said:
internal materials failure.... but really, what difference does it make?
Jaybird's right that a prop that sheds a blade or a significant amount of mass could rip the engine right off the airplane, which could render the airplane unrecoverable.

I'd like to think that an event like that might be over very quickly, or discernible from a busted cylinder or other problem, so that the pilot could make an informed decision whether it's necessary to shut down the engine.
Click to expand...

An engine suffering a partial power loss, even from a broken or stuck valve, will vibrate much, much less than an engine that has lost even a few inches off a prop blade. The vibration from a failed prop is VIOLENT. One would have a hard time even finding the throttle knob to pull it out.

Dan
 
dennyleeb said:
huh, learn something every day

but the older 182's are conti's right? maybe I just assumed they used em in both

either way glad your safe
Click to expand...

182s had the Continental O-470 up to the 182R. Then Cessna quit building piston singles until 1996. The T182, built until the mid-80s, had the Lycoming O-540 in it, as did the R182/TR182 (retractable/turbo retractable) models.

The info on just about any US-made airplane is available on the TCDS section of the FAA website.
http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/MainFrame?OpenFrameSet

Dan
 
Ron Levy said:
Failure from a fatigue crack resulting in part of one blade letting go. And yeah, that happens.
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I would hope that if there was a fatigue crack, that you would see it during the preflight.

Here is one that wasn't found, but that was due to a rubber boot covering the crack:
http://aviation-safety.net/database/record.php?id=19760208-0

Like Dan Thomas mentioned, I think you'll definitely know whether or not to kill the engine if it happens and the engine may very well depart the plane before you even have that option.

There is a big difference between rough running and violent shaking.
 
Fearless Tower said:
I would hope that if there was a fatigue crack, that you would see it during the preflight.

Here is one that wasn't found, but that was due to a rubber boot covering the crack:
http://aviation-safety.net/database/record.php?id=19760208-0

Like Dan Thomas mentioned, I think you'll definitely know whether or not to kill the engine if it happens and the engine may very well depart the plane before you even have that option.

There is a big difference between rough running and violent shaking.
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Next time you are on the ramp take a look at various prop blades. Can you determine the stress riser? IOW, how much is too much? And that assumes nothing will change in the course of various power settings, etc during the course of a normal flight.

Amelia Reid, who taught Rod Machado to fly, used a wooden stick to tap the blade along it's length. Listen to the resonance. It's something I do. You may not see it even if it is there.
 
What do you listen for? Same sounds on each prop... the tone changing evenly along the length of the blade?
 
I can't imagine the vibration a failed prop could cause. I would imagine it would be something pretty extreme. I ALWAYS check the prop for nicks, but never heard of tapping it and listening to resonance.
 
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