Rough Running Engine
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with regard to EAs EFOT post and SNS's response
If you're trimmed for the climb, you're trimmed close to the glide. In general terms, your best glide speed will closely approximate your sea level best rate of climb speed (Vy), and your minimum sink glide speed will closely approximate your sea level best angle of climb speed (Vx). If you're trimmed for one of these speeds on the climb, a power loss will result in a trimmed descent at that speed if you don't get involved (i.e. pulling back and interfering with the airplanes ability to do it's job...remain stable).
To be more specific, I understand the point that you are trimmed for an AoA so the change in excess power from positive to negative should over time result in the same airspeed but a sink rate rather than a rate of climb.
BUT, with a sudden lack of power, the aircraft flight path needs to move from say 6 degrees up (750 fpm climb @ 75kts) to 6 degrees down (typical 1 in 10 glide ratio), which it will do pretty quickly, but the airframe needs to rotate the same 12 degrees at the same rate that your climb moves to descent (i.e. fast) otherwise your AoA will be temporarily increasing, increasing drag, loosing airspeed and sapping energy out to rotate the aircraft.
All of this added to the fact that until you are level, part of the lift vector is slowing you down and you need to get most of the way through the rotation before you have eliminated the deceleration from drag, induced drag and the rearward component of lift.
Last edited by mm_flynn; 16th Jan 2008 at 20:58. Reason: to clarify the context
Avoid imitations
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Exactly our thinking on the C152/0. I have even see fuel cocks drilled and wire locked on!!!!!
Presumably a pair of sidecutters was provided for use in the case of an engine fire?
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Are you sure?
So far as a need to scream, panic, or fear a rough or failed engine...you're flying an airplane with wings. It doesn't depend on an engine to fly. That's why it's not an engineplane, but an airplane (or "aeroplane" if you happen to breathe aero). You flew it up there, fly it back down.
Agressively manhandling the airplane isn't required to fly it back down.
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After having read most of the posts here, for which I concur on most of the advice given. For me, I am always looking for suitable landing areas as flying at below 500 for most of my career demands it.
However, one interesting aspect I have come to notice in training our new PPL pilots today (in OZ anyway) is that they are taught to land with power mostly on, and to do longer approaches. I realise that this somewhat alleviates the problem of an engine misfiring due to carby conditions or such like, but if the engine does konk then ...... well....... sorry about the bent a/c.
What happened to doing glide approaches. Its safe, teaches a hell of a lot re a/c performance in lots of different circumstances, and it may save your life and those of others one day (esp if you happen to want to put down in a school playground)
Sure when you get into larger a/c, I can understand the need of keeping a brick aloft with brute power, but for most single piston engined............
My cents worth
However, one interesting aspect I have come to notice in training our new PPL pilots today (in OZ anyway) is that they are taught to land with power mostly on, and to do longer approaches. I realise that this somewhat alleviates the problem of an engine misfiring due to carby conditions or such like, but if the engine does konk then ...... well....... sorry about the bent a/c.
What happened to doing glide approaches. Its safe, teaches a hell of a lot re a/c performance in lots of different circumstances, and it may save your life and those of others one day (esp if you happen to want to put down in a school playground)
Sure when you get into larger a/c, I can understand the need of keeping a brick aloft with brute power, but for most single piston engined............
My cents worth
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Yes.
So far as a need to scream, panic, or fear a rough or failed engine...you're flying an airplane with wings. It doesn't depend on an engine to fly. That's why it's not an engineplane, but an airplane (or "aeroplane" if you happen to breathe aero). You flew it up there, fly it back down.
Agressively manhandling the airplane isn't required to fly it back down.
So far as a need to scream, panic, or fear a rough or failed engine...you're flying an airplane with wings. It doesn't depend on an engine to fly. That's why it's not an engineplane, but an airplane (or "aeroplane" if you happen to breathe aero). You flew it up there, fly it back down.
Agressively manhandling the airplane isn't required to fly it back down.
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Rough running, the title of the thread dosnt need aggresive handling but it does need decisive handling and looking at the posts I cannot see much evidence of any methodical plan, more throwing in a couple of thoughts that might help.
Knowing Bob as I do and knowing his meticulous detail I have a feeling he is waiting for the correct moment to publish his easy logical series of actions.
Knowing Bob as I do and knowing his meticulous detail I have a feeling he is waiting for the correct moment to publish his easy logical series of actions.
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Airmuster... oh if only you were here a few weeks ago - there was a very enlightening thread on the pro's & con's of teaching and/or doing glide approaches. 
SNS3Guppy
Well, I like your logic here. And I'm not normally one to argue. 
But when your rough running occurs EXACTLY midway across cook strait, altitude due weather prevents you gliding to either shore, then scream & panic & swear is not the FURTHEST from one's mind....
(I think it comes a close second to: jaysus that's gonna be freezing, and did I just see a SHARK??)
SNS3Guppy
You flew it up there, fly it back down.
But when your rough running occurs EXACTLY midway across cook strait, altitude due weather prevents you gliding to either shore, then scream & panic & swear is not the FURTHEST from one's mind....
(I think it comes a close second to: jaysus that's gonna be freezing, and did I just see a SHARK??
)
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Haha, yes...........
Funny how there's never one around when you need it.
Or how willing your pax are to point out all the dark shadows lurking under the water...
Funny how there's never one around when you need it.
Or how willing your pax are to point out all the dark shadows lurking under the water...
HA! I employed the same technique whenever my students flew me out too far over the water. I'd crane my neck around and say "Look of the size of that shark. Is that a Mako or Great White?" Suddenly the aircraft would deviate closer to within gliding range of land...
Thread Starter
Knowing Bob as I do and knowing his meticulous detail I have a feeling he is waiting for the correct moment to publish his easy logical series of actions.
My observation is that many replies focus on the procedural aspects of addressing the rough running engine. I was interested to see how much emphasis was put on pointing the a/c (I am assuming single engine) towards the nearest suitable aerodrome and (if possible) gaining height before executing a forced landing from the overhead.
As various posters have indicated there are a lot of variables, hence no strictly right answer - my question was deliberately vague - I wonder who taught me that...............
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Yes, virtually no one mentioned gaining altitude and I think only one mentioned surface wind considerations.
Vague questions provoke more thought and yes I know who taught you that!
Miss FM at Humberside too!
Vague questions provoke more thought and yes I know who taught you that!
Miss FM at Humberside too!
