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DavidWhite

DavidWhite

Final Approach
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Today while doing our second job in North Platte, NE we preflighted and jumped back in the airplane. I started it up, started my taxi, and then it just started running like ****. Dieseling, throttle lag, mags checked fine though. Made the no-go decision and called Jesse for a Mooney rescue.

Well, Jesse landed in the Mooney and got out shaking his head - the left mag wasn't running right. I jumped in to confirm, and sure as **** it ran like a massage chair on the left mag. Made a second no-go decision and the three of us are currently driving back via rental car.

Wah-wah.
 
This was my first mx related no-go when the get-there-itis was very high. It is REALLY difficult to turn the airplane back to the ramp and tell your pax you aren't going.

But it is the right choice.
 
Seems like a much simpler exercise to me. Just hand him the keys and tell him you're not going but whatever he wants to do is up to him.

DavidWhite said:
This was my first mx related no-go when the get-there-itis was very high. It is REALLY difficult to turn the airplane back to the ramp and tell your pax you aren't going.

But it is the right choice.
Click to expand...
 
When and how long ago was the duel mag inspected and repaired and who did it?
 
wabower said:
Seems like a much simpler exercise to me. Just hand him the keys and tell him you're not going but whatever he wants to do is up to him.
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He's actually great - didn't squawk at all. His response "Do what you think is safe." Really speaks volumes of his character. The other surveyor that I used to work with would have had a problem. We don't work well together (but the new guy and I do)
 
I also find it funny that in another thread a poster said that run-ups are only necessary for the first flight - this was the third and I had a problem. Plane ran fine all day.
 
DavidWhite said:
I also find it funny that in another thread a poster said that run-ups are only necessary for the first flight - this was the third and I had a problem. Plane ran fine all day.
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Every flight is a first flight for me... run-up every time.
 
I'm more interested in why the other plane was "Dieseling", WTF is up there? Bad fuel? Contaminated by Jet A? If so they owe a new engine.
 
Well how was the drive,at least you had something to talk about.good luck with the plain good pre flight procedure.
 
FWIW, I consider mags to be 500-hour items. I think the Mooney has under 500 SMOH, but from what you've told me of the plane it wouldn't surprise me if the mags weren't done. I would consider doing both mags. I've had a mag go bad, replace it, and have another one go bad on the run-up post repair.
 
Ted DuPuis said:
FWIW, I consider mags to be 500-hour items. I think the Mooney has under 500 SMOH, but from what you've told me of the plane it wouldn't surprise me if the mags weren't done. I would consider doing both mags. I've had a mag go bad, replace it, and have another one go bad on the run-up post repair.
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You forgot the mooney has this thing:



These buggers need to be IRAN'ed every 500 hrs and the impulse spring should be replaced at that time also regaurdless. I would also do the the lycoming service bulletin for the 66M19385 clamps if it hasn't been done yet
 
Do you guys recommend IRANing one mag at a time on a 500 check or both at the same time?
 
Both, assuming that both actually have 500 hours on them since last inspection or 500 hours since new. No regulatory requirement, just personal preference.
 
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bnt83 said:
You forgot the mooney has this thing:



These buggers need to be IRAN'ed every 500 hrs and the impulse spring should be replaced at that time also regaurdless. I would also do the the lycoming service bulletin for the 66M19385 clamps if it hasn't been done yet
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Ahh, I didn't know that - the Mooney I flew had normal mags, an F model.

The dual mag is a rotten setup. I never met anyone who liked it. Definitely a 500 hour item.

Alexb2000 said:
Do you guys recommend IRANing one mag at a time on a 500 check or both at the same time?
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Good question. If you did what the airlines do, you'd probably only do one at a time. Personally I used to replace one at a time when it failed. The plan going forward is to do all 4 at once, mainly for convenience and I think there's a higher probability of maintenance error for removing/timing/etc twice vs the error possible in overhauling the mags themselves, which is easy.
 
Henning said:
I'm more interested in why the other plane was "Dieseling", WTF is up there? Bad fuel? Contaminated by Jet A? If so they owe a new engine.
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Wondering the same thing. Maybe it was the wrong way to put it. When I think of dieseling, I think of mags off and the thing still runs.

Contaminated fuel is my guess, if it passed a mag check. Maybe water. Sometimes they will do okay with some water in the fuel at high power, then at lower power run rough.
 
Ted DuPuis said:
If you did what the airlines do, you'd probably only do one at a time.
Click to expand...

Airlines have to follow a AAIP nowdays, which will say to do them whenever they are due (including a calandar limit). If one failed before the 500 hrs was due and was repaced with a fresh one, then yes, they wouldn't be on the same schedule.

This is much like firebottle squibs, each needs to be tracked individually.
 
bnt83 said:
Airlines have to follow a AAIP nowdays, which will say to do them whenever they are due (including a calandar limit). If one failed before the 500 hrs was due and was repaced with a fresh one, then yes, they wouldn't be on the same schedule.

This is much like firebottle squibs, each needs to be tracked individually.
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You are correct. However many airlines purposely stagger various MX items (sometimes replacing a hair early on one) to minimize the possibility of a maintenance-induced double failure. Obviously I am more familiar with the engine side than airframe, but we're talking engines.
 
bnt83 said:
You forgot the mooney has this thing:



These buggers need to be IRAN'ed every 500 hrs and the impulse spring should be replaced at that time also regaurdless. I would also do the the lycoming service bulletin for the 66M19385 clamps if it hasn't been done yet
Click to expand...

IIRC the cost of the clamps is very close to the cost of a new mag.
 
Do we know if he bought fuel? If yes, was it from truck or self-serv? If yes, when was last sale prior?
 
It was from a truck. I sumped it, and watched the guy use the 100LL truck. I'd say they probably had at least a few 100LL sales that day.
 
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Did you confer with the FBO to verify? If not, maybe worth a call?

DavidWhite said:
It was from a truck. I sumped it, and watched the guy use the 100LL truck. I'd say they probably had at least a few 100LL sales that day.
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One day I jokingly asked the fuel truck guy if there was any water in that fuel he was putting in my airplane. He said "Na, I pumped it all out into the first plane I filled up this morning" :)

Usually a quick sump will catch any water, but if there is any sign of water present its worth rocking the wings and filling the jar up a time or two.
 
How much time is required between the fill and the sump in order to to know about water content?

dell30rb said:
One day I jokingly asked the fuel truck guy if there was any water in that fuel he was putting in my airplane. He said "Na, I pumped it all out into the first plane I filled up this morning" :)

Usually a quick sump will catch any water, but if there is any sign of water present its worth rocking the wings and filling the jar up a time or two.
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DavidWhite said:
I've always heard 5 mins, is that accurate?
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Depends...

I don't know what you are flying, but on the Cherokee's/Cessna's we always shake the wings before preflight, it makes us feel better that any water stuck in a crevis will find its way to the bottom by the time we sump it.
 
FWIW, Dassault gave a weigh procedure that says to jack and level the plane, then let it sit 4 HOURS prior to the final sumping, then take the scale readings during a weigh.

4 hours then sump. :goofy:

Granted thats for a weigh ie empty, but still :goofy:
 
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DavidWhite said:
I also find it funny that in another thread a poster said that run-ups are only necessary for the first flight - this was the third and I had a problem. Plane ran fine all day.
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Every flight is your first since the last one.

wabower said:
How much time is required between the fill and the sump in order to to know about water content?
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Great question! I don't know so I usually ask the line guys to fuel me upon arrival so that the water has time to settle out by the time I leave or at least more time.

So what exactly is deisling? In my mind I think the engine runs like a motor boat or harley? But what is it exactly?
 
AdamZ said:
So what exactly is deisling? In my mind I think the engine runs like a motor boat or harley? But what is it exactly?
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It would mean that the engine would continue to run with the mags off (run without spark). Something needs to be hot enough to cause the fuel to continue to ignite. Could be hot carbon in the cylinder.

I'm not sure if that is what was occurring of if David meant something else.

Diesel engines fire by compressing the hell out of hot air and then injecting the fuel at the topish of the compression stroke. No spark plug, hence the term.
 
jesse said:
It would mean that the engine would continue to run with the mags off (run without spark). Something needs to be hot enough to cause the fuel to continue to ignite. Could be hot carbon in the cylinder.

I'm not sure if that is what was occurring of if David meant something else.

Diesel engines fire by compressing the hell out of hot air and then injecting the fuel at the topish of the compression stroke. No spark plug, hence the term.
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How does he know he doesn't have a hot mag?
 
I'm guessing it just ran poorly and he used the wrong term.

As far as the filling and the sumping just a few minutes should be enough for the water to settle out. I base this on quite a bit of experience testing mogas for ethanol. Using non-ethanol mogas, if you put about 1 part water to 5 parts fuel in a test tube, then shake the hell out of it - the water and fuel are completely separated in 30 seconds.
 
Well . . .

jesse said:
It would mean that the engine would continue to run with the mags off (run without spark). Something needs to be hot enough to cause the fuel to continue to ignite. Could be hot carbon in the cylinder.
Click to expand...

Based on what David said

DavidWhite said:
Today while doing our second job in North Platte, NE we preflighted and jumped back in the airplane. I started it up, started my taxi, and then it just started running like ****. Dieseling, throttle lag, mags checked fine though. Made the no-go decision and called Jesse for a Mooney rescue.
Click to expand...

I suspect it was something else. The way I understand it, dieseling will only happen on shut down. Everything shut off and the engine still running. I can't envision how that would work with mags and fuel on.
 
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