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Posted

Pilot reported an occurrence of his engine quitting after landing on rollout. It was re-started and taxied back to the hangar without further issue. I thought I read this happening to another MS’er before. Open to thoughts on what to look for. 
Thanks,

David

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Posted
5 minutes ago, Sabremech said:

Pilot reported an occurrence of his engine quitting after landing on rollout. It was re-started and taxied back to the hangar without further issue. I thought I read this happening to another MS’er before. Open to thoughts on what to look for. 
Thanks,

David

I'll bet it was a Continental.

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  • Haha 1
Posted
15 minutes ago, Fly Boomer said:

I'll bet it was a Continental.

And we are off to the races!

Posted

If it was a Continental, it is most likely a slightly too lean an idle mixture. Easy tweak for a Mooney A&P, or a mildly talented hangar elf.

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Posted
19 minutes ago, M20F said:

And we are off to the races!

 

35 minutes ago, Fly Boomer said:

I'll bet it was a Continental.

Nope! Lycoming IO-360 in an M20J. 

  • Sad 1
Posted (edited)
2 hours ago, Sabremech said:

Pilot reported an occurrence of his engine quitting after landing on rollout.

At their Home Airport or while on a XC?  If a XC, what airport and what was the Density Altitude? 

I had that happen to me on my first X-US flight in a Cherokee Six when I rolled off the runway at Coronado, NM (4AC which isn't there any more).  I was still in the "Full Rich" mentality and the engine did not like all that fuel at that altitude. :wacko: 

But probably just a quick tweak by their mechanic of the idle RPM or the idle mixture.

 

Edited by PeteMc
Posted

This did come up a while back, and there was a lot of thought about where the mixture control was left during approach.   If the idle is set low and it's full rich at high DA, or too lean at lower altitude, it may have difficulty idling against the stop.    More annoying than catastrophic.

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Posted (edited)
14 minutes ago, EricJ said:

This did come up a while back, and there was a lot of thought about where the mixture control was left during approach.   If the idle is set low and it's full rich at high DA, or too lean at lower altitude, it may have difficulty idling against the stop.    More annoying than catastrophic.

@Sabremech, Eric nailed it.  It was mine.  Very high Da landing (like 9500’ ish).  I didn’t have the mixture full or too lean.  It was probably a tad too rich if anything, but maybe an inch back.  With the throttle at full idle, that shouldn’t matter.  My idle is set real low (like 500ish I think) and generally that’s fine but apparently it needs a little more air at very high altitude… 

Edited by Ragsf15e
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Posted
12 minutes ago, EricJ said:

This did come up a while back, and there was a lot of thought about where the mixture control was left during approach.   If the idle is set low and it's full rich at high DA, or too lean at lower altitude, it may have difficulty idling against the stop.    More annoying than catastrophic.

This was in the Midwest and it was warm but I don’t  believe anything out of the ordinary. Idle setting hasnt been an issue or mixture setting either. Pilot has 3000 plus hours in this bird and it’s the first time this has happened to him. 
Thanks again.

Posted

There are many ways in which the operation of a turbocharged aircraft are completely different from a normally aspirated aircraft. Pilots of one type make assumptions, come to conclusions or give advice about the other from their own perspective and the answer or conclusion can be 180 degrees wrong. So without knowing what the aircraft was and what engine it had in it, there is no way to come to any conclusion about what happened.

NA pilots, for example, are taught to put in full mixture during the landing phase in case they have to go around. The theory is that if a go around becomes necessary, putting in full mixture is one less thing to do. However, in at least some turbocharged aircraft, the engine is set up to run very rich to protect the engine at full power, in takeoff and during the climb. It is set up so rich that during the final descent to landing the engine will "burble" unless it is leaned out quite a bit. The burbling is not a true miss, a true miss being a cylinder failing to fire. Rather, there is so much fuel and the engine is producing so little HP in that regime of flight that the cylinder fires but the fire is drowned out quickly by the excess fuel. To avoid this we turbocharged pilots lean the engine out quite a bit during the approach to landing. So much so that on occasion we lean it a little too far and forget to put some mixture in right at touch down. When the plane is no longer descending and the prop is no longer being helped by the airspeed the engine can quit on the ground because of too little fuel. The fix, if you hear it happening, is to quick push the fuel knob in. 

When I first started flying my TSIO360 years ago, being a freshly trained NA pilot (Slohawks, Warriors and Archers) I would put the mixture full in for landing. People on the ground would tell me that there was something wrong with my engine, it was missing during the landing. So I figured out to lean the engine out during the descent and me, the engine, and the people waiting on the ground are all much happier.

Oh, and it may come as a surprise to NA pilots, but there is no great trick to pushing in the fuel knob for a go around. You have no choice, if the engine is leaned out it will struggle if you just put in MP. I have done a few emergency go arounds, deer or geese on the runway for example, it has just never been an issue.

So back to the OPs question. There is no way to answer without knowing the engine in the aircraft. If it is an NA engine, then maybe some engine adjustment is in order. If it is a turbo'd engine, the pilot may need to change his methods and put in some fuel (not MP) at the runway.

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Posted

Happened to my E on landing at high and hot if at idle and full rich.  Didn't need to be anywhere near 9,500 DA.  A little throttle on rollout would catch it, but happened to me twice while focused on other things (getting stopped)

Posted

It’s a non turbo J model. Owner is high time in this airplane and this is not normal for it. Appreciate some ideas to just verify. 
Thanks again,

David

Posted

RSA servos don't meter fuel according airflow below about 1200 - 1500 rpm because there isn't enough air flow through the venturi and into the impact tubes to create the necessary differential pressure across the air diaphragm. There is a spring in the regulator that holds the ball valve off the seat to let some fuel flow into the metering section but the mixture at low throttle settings is controlled by a mechanical linkage on the throttle to an idle mixture valve. At high density altitudes, as the airplane slows down on the rollout with the throttle closed, there isn't enough air and the mixture will be too rich. You cannot really fix this by manual leaning during the let down because you'd have to lean so aggressively that the engine wouldn't run above 1000 rpm. The solution if it starts to die is to just give it a little throttle. If it's doing it all the time, adjust the idle speed and idle mixture.

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Posted
37 minutes ago, PT20J said:

RSA servos don't meter fuel according airflow below about 1200 - 1500 rpm because there isn't enough air flow through the venturi and into the impact tubes to create the necessary differential pressure across the air diaphragm. There is a spring in the regulator that holds the ball valve off the seat to let some fuel flow into the metering section but the mixture at low throttle settings is controlled by a mechanical linkage on the throttle to an idle mixture valve. At high density altitudes, as the airplane slows down on the rollout with the throttle closed, there isn't enough air and the mixture will be too rich. You cannot really fix this by manual leaning during the let down because you'd have to lean so aggressively that the engine wouldn't run above 1000 rpm. The solution if it starts to die is to just give it a little throttle. If it's doing it all the time, adjust the idle speed and idle mixture.

Happened once. Not a common issue but something entirely out of the normal for this aircraft after all his years of flying. The owner puts at minimum 100 hours a year on his airplane. 

I have a few things to look at and Will do so. Plan to fly it Friday after looking it over and doing a ground run or two. 
Thanks again,

David

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Posted

Spark, Fuel and Air.

I had an airplane that every once in awhile would stumble after landing and died a couple of times. The resistance in the Champion plugs was very high. I put in Tempest fine wire and never had the issue again.

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Posted
3 hours ago, LANCECASPER said:

Spark, Fuel and Air.

I had an airplane that every once in awhile would stumble after landing and died a couple of times. The resistance in the Champion plugs was very high. I put in Tempest fine wire and never had the issue again.

This one has the Tempest fine wires installed.

Thanks,

David

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Posted
1 hour ago, Sabremech said:

This one has the Tempest fine wires installed.

Thanks,

David

I’m sure you know this and have probably pulled all of the plugs for inspection, but there was a run of tempest plugs back around 2018 or so where they had farmed out production and the electrodes came out. I understand that in the last few years they moved production back in-house.

 

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Posted
6 hours ago, LANCECASPER said:

I’m sure you know this and have probably pulled all of the plugs for inspection, but there was a run of tempest plugs back around 2018 or so where they had farmed out production and the electrodes came out. I understand that in the last few years they moved production back in-house.

I just had 2 from that era fail in this way this year. 
-dan

 

Posted

I had a similar occurrence, landing at sea level, full rich, cool day. Engine cut out just as I let the nose wheel down on the pavement. Started right up when I bumped the starter. Had the Idle and idle mixture adjusted and it didn't happen again until one day when I did a power off 180, saw I was coming up short so I pulled the prop lever all the way back to extend the glide. I easily made the runway but the prop stopped before I touched down

the idle seems correct when warmed up on the ramp, although I find that the fully retarded throttle stop is a little soft. If I just pull it gently back I idle around 650. If I pull it firmly against the stop it goes down to 500-550.

Now when I land I slightly back off the throttle from the idle position

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Posted
On 7/29/2024 at 9:07 PM, Sabremech said:

This was in the Midwest and it was warm but I don’t  believe anything out of the ordinary. Idle setting hasnt been an issue or mixture setting either. Pilot has 3000 plus hours in this bird and it’s the first time this has happened to him. 
Thanks again.

I was taught to land by a Mooney Safety Instructor to land with mixture at cruise setting (don't touch anything to descend other than pulling throttle back).    If you go around then add mixture.    I would ask when the last time his fuel Servo was rebuilt.   The guys in Justin Texas did mine.   No problems since.

Posted

I ended up inspecting the spark plugs as they are fine wires. Cleaned and rotated them as I usually do. Ground run was good with idle at about 650-660 rpm. 
The owner flew it yesterday and reported no issues. We’ll continue to monitor to see if this was a one off occurrence. 

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