First declared emergency

DesertNomad

Pattern Altitude
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DesertNomad
I was flying KFTW to KELP today in IMC at 10,000' at 40 deg F. Tail winds were good (168kts over the ground!) so we changed our destination to KDMN. About 8-10 miles northwest of KELP, I noticed the plane slowing a bit, then cylinder #5 went cold. It slowly dropped to about 230 CHT and 1000 EGT, then much lower than even that.

We declared an emergency and headed to KELP. We broke out the the clouds just west of the mountain ridge west of the field and found a nice gap to go through. It was running ok and we had to make a few S-turns to get down to 8R.

As I got lower it felt like it ran worse at low power so I kept the power in and told tower that it might quit on the runway. I make a perfect landing and on roll-out, the engine did quit. I didn't really have time to troubleshoot things and just wanted to be out of IMC and on the ground. It may have quit due to too lean mixture but I don't think so - otherwise more power on approach should have made it worse.

A local mechanic started it and it ran ok. He removed all 12 plugs and said the ones on #5 were not working at high power but cleaned them and now they work. I don't think I was running overly rich... 67% power and about 13.1gph. All cylinders checked out at 75 or 76/80. Exhaust looks fine. Dunno - bit of a mystery. The mechanic and I took it two laps around the pattern here.

Any ideas?
 
I was flying KFTW to KELP today in IMC at 10,000' at 40 deg F. Tail winds were good (168kts over the ground!) so we changed our destination to KDMN. About 8-10 miles northwest of KELP, I noticed the plane slowing a bit, then cylinder #5 went cold. It slowly dropped to about 230 CHT and 1000 EGT, then much lower than even that.

We declared an emergency and headed to KELP. We broke out the the clouds just west of the mountain ridge west of the field and found a nice gap to go through. It was running ok and we had to make a few S-turns to get down to 8R.

As I got lower it felt like it ran worse at low power so I kept the power in and told tower that it might quit on the runway. I make a perfect landing and on roll-out, the engine did quit. I didn't really have time to troubleshoot things and just wanted to be out of IMC and on the ground. It may have quit due to too lean mixture but I don't think so - otherwise more power on approach should have made it worse.

A local mechanic started it and it ran ok. He removed all 12 plugs and said the ones on #5 were not working at high power but cleaned them and now they work. I don't think I was running overly rich... 67% power and about 13.1gph. All cylinders checked out at 75 or 76/80. Exhaust looks fine. Dunno - bit of a mystery. The mechanic and I took it two laps around the pattern here.

Any ideas?

Can you post your engine logs on the free Savvy site?

What engine?
 
other than the engine monitor readings was there any other indication of an issue? loss of power, etc...?
 
Losing one cylinder would make it rough, but it should still idle on the remaining 5 - did you try carb heat? Did the temperatures in the other cylinders remain good?
 
Can you post your engine logs on the free Savvy site?

What engine?

I'll DL the logs when I get back to the plane. It's an O-540 that has never given me any trouble in 360 hours... 850 TT on the engine.

other than the engine monitor readings was there any other indication of an issue? loss of power, etc...?

It was on auto pilot with altitude hold and I felt it pitching up and slowing down, then noticed Cyl#5 was low - 310 vs the others at 350-360 or so. Over the next 10 seconds we watched #5 just fall and the bar graphs go away. It was running a bit rough, but not dramatically. As we got lower some power came back - EGT got back up to 1100. I don't think it is the probes since both EGT and CHT were falling.
 
Losing one cylinder would make it rough, but it should still idle on the remaining 5 - did you try carb heat? Did the temperatures in the other cylinders remain good?

I did not try carb heat. I was very focused on hand flying in IMC and getting back to ELP. I would think that carb ice would affect all the cylinders. The other CHTs and EGTs remained normal.
 
You were in cruise for quite some time. Most likely no change to RPM, MP or mixture prior to #5 going cold?
Spark plugs don't suddenly foul in that situation.

Suggests something else perhaps caused one of the plugs in #5 to stop firing, and then it fouled.

If it was my plane I would start with the cheapest and simplest thing and work up. Install 2 new plugs in #5 and then try to re-create the problem, at altitude. If it re-occurs start digging into the rest of the ignition system.
 
He did clean gap and test all 12 plugs and said the ones on #5 were not right but are now. We were in visible moisture but 3 hours into a 3:40 flight. I had not touched the mixture control for more than an hour. When we depart tomorrow, I plan to file IFR but first fly up to 10K over the airport and circle a couple laps before heading off.
 
I second that. Nice job keeping calm under pressure! Look forward to any updates that follow this event.
 
Something caused both plugs in the same cylinder to not look right (whatever that actually means). That something was not the plugs’ fault. I’m more risk averse than most, so I wouldn’t fly until I got a specific root cause.
 
Two folks on Piper Forum said:

I used to have a normally aspirated Saratoga and had fouling issues with one cylinder. It often would loose power on cylinder 3 if I remember right and run rough. At that time I ran ROP usually 75 to 100 degrees and conventional spark plugs. When this happened, I would pull it very lean and it cleared up.

and

What you describe is a classic presentation for carb icing, one cylinder goes cold, and typically then another, etc. It has happened to me. In IMC at 40F OAT, is certainly consistent.


I was under the impression that carb ice would make it run rough and it did not run rough so much as just slowed down and then #5 went cold.
 
Two folks on Piper Forum said:

I used to have a normally aspirated Saratoga and had fouling issues with one cylinder. It often would loose power on cylinder 3 if I remember right and run rough. At that time I ran ROP usually 75 to 100 degrees and conventional spark plugs. When this happened, I would pull it very lean and it cleared up.

and

What you describe is a classic presentation for carb icing, one cylinder goes cold, and typically then another, etc. It has happened to me. In IMC at 40F OAT, is certainly consistent.


I was under the impression that carb ice would make it run rough and it did not run rough so much as just slowed down and then #5 went cold.

Doesn't run right first thing carb heat. You did well though, great job.
 
hey what time was that, I passed over elp at 7:30am and again at 3:00pm - el paso was not its usual clear warm sunny self! I had the heat and boots on for much of that time, at 18K.
 
Two folks on Piper Forum said:

I used to have a normally aspirated Saratoga and had fouling issues with one cylinder. It often would loose power on cylinder 3 if I remember right and run rough. At that time I ran ROP usually 75 to 100 degrees and conventional spark plugs. When this happened, I would pull it very lean and it cleared up.

and

What you describe is a classic presentation for carb icing, one cylinder goes cold, and typically then another, etc. It has happened to me. In IMC at 40F OAT, is certainly consistent.


I was under the impression that carb ice would make it run rough and it did not run rough so much as just slowed down and then #5 went cold.

You can't know with certainty it wasn't carb ice, but you didn't have "one cylinder goes cold, and typically then another, etc...", so I am skeptical that was the cause.

I typically cruise at 10k or higher and aggressively lean my injected 540s, usually no more than 11.5 gph each side in cruise. If I run ROP the lead fouling on the bottom plugs is much greater. As yours is carbureted you might be running very rich on #5 just the way the manifold distribution worked out - You mentioned you are burning 2 gph more than I do. But you and your mechanic should see evidence of that on the plugs every time they were pulled for servicing.
 
Whatever

You saw what you thought was a problem, you asked for what you needed, you landed safe.


Well done.
 
Great job staying calm and getting on the ground in one piece.. especially in IMC!

67% power and about 13.1gph

usually no more than 11.5 gph

My only thoughts are that you may have been a touch rich, 13+ gph at 65% seems high and carb heat at 40F and IMC with fuel pump on would have been my first thing to do. Did you try enriching or leaning further to see if temps change?

At any rate, nice work and thanks for write up, nice to learn from others on these forums
 
My only thoughts are that you may have been a touch rich, 13+ gph at 65% seems high and carb heat at 40F and IMC with fuel pump on would have been my first thing to do. Did you try enriching or leaning further to see if temps change?

At any rate, nice work and thanks for write up, nice to learn from others on these forums

I think I enriched some but I was getting further from ELP with each second so getting headed to the airport was my first priority. It was in and out of IMC all the way to about 2000' AGL so I didn't spend much time troubleshooting. Definitely a good learning experience.

This article was mentioned on the red board about bad Champion plugs.

https://blog.aopa.org/aopa/2015/03/...828.798986106.1520811775-645701614.1460523417
 
Another :thumbsup: from me for keeping cool and handling the situation. I've yet to have an emergency situation in IMC, but have to imagine that it's much more stressful and nerve-wracking than when in VMC.
 
#5 went cold during run up today. In the shop and thinking an intermittent sticking valve.
 
#5 went cold during run up today.
Wow, that's why we do runups! In a weird way it probably feels good to be able to see the problem come back, hopefully that helps troubleshoot

Good luck and hopefully it will not be too $$. Look forward to hearing what the root cause is
 
I think I enriched some but I was getting further from ELP with each second so getting headed to the airport was my first priority. It was in and out of IMC all the way to about 2000' AGL so I didn't spend much time troubleshooting. Definitely a good learning experience.

How did KELP transition you for your approach? Reason I ask is that many here do not realize there is no GPS/ILS for RWY 8R at El Paso and further RWY 22-4 is currently closed. KLRU (Las Cruces) was physically closer, but being high helped you out, and not sure if KLRU would be able to help you much. Can sure understand you having your hands full with that approach with the above info ... good job!

#5 went cold during run up today. In the shop and thinking an intermittent sticking valve.

If you need help while here, give me a call at my office 544-4624.
 
I suggest the ignition harness. If it is not recently new/looking perfect, it could be the culprit. There is no way to "inspect" like a plug.
 
How did KELP transition you for your approach? Reason I ask is that many here do not realize there is no GPS/ILS for RWY 8R at El Paso and further RWY 22-4 is currently closed. KLRU (Las Cruces) was physically closer, but being high helped you out, and not sure if KLRU would be able to help you much. Can sure understand you having your hands full with that approach with the above info ... good job!.

I was maybe 8 miles NW of ELP - have to go back and look. I got a turn to I think 120 and was asked to turn right. I asked to turn left and it was granted (I was on a heading of about 280 I guess). We ended up on the other side of the mountains west of ELP. I wasn't sure the engine would keep runnig so I wanted to be sure I could clear them. went through a gap in them and all other traffic was cleared so I didn't really fly an approach at all. I was at 10K and by 8K was between layers. there was a layer just under the summit of the mountains west of the field but it was really thin - I could see down but not ahead.

We made it out to Lake Havasu - it was a sticking valve on #5 since that seems to have fixed it.
 
...We made it out to Lake Havasu - it was a sticking valve on #5 since that seems to have fixed it.

Great to hear you are airborne again, but what exactly was done to fix it?
 
You do realize running over rich like you're doing causes sticky valves right? 13.1gph at 10K and ISA+10 on a super de-rated naturally aspirated O-540 (2400RPM artificial redline) is almost 2gph rich. You're running super rich man, pull that red knob back, seriously. Granted, parallel Lyco cylinders are super cheap to keep and IRAN, but still. :D
 
I'm pretty sure that your plane is FUBAR. Just leave it with me for responsible disposal and go get another.
 
For those unfamiliar, Nomad was probably near Anthony Gap. Biggs field military runway is 3 miles closer and same orientation as our closed runway at KELP if the stuff was really hitting the fan.
 
You do realize running over rich like you're doing causes sticky valves right? 13.1gph at 10K and ISA+10 on a super de-rated naturally aspirated O-540 (2400RPM artificial redline) is almost 2gph rich. You're running super rich man, pull that red knob back, seriously. Granted, parallel Lyco cylinders are super cheap to keep and IRAN, but still. :D

Hmm... that fuel flow seems right for best power according to the POH and is about 100 deg ROP according to the JPI.
 
Hmm... that fuel flow seems right for best power according to the POH and is about 100 deg ROP according to the JPI.

Don't get me wrong, your monkey your circus, but according to the -236 POH, ROP @ 50 degrees rich (which is terrible advice anyways) puts you at 11.8GPH on a best power setting for your ISA+10 condition (page 5-22 of your POH if it's the 1978 revision). You running 50 degrees even richer of that setting is not getting ya any more cruise speed but may be contributing to your valves sticking over hours of operation. Remember, your engine (parallel valve Lyco) was originally built for red avgas (80/87). 100LL (blue) has 3 times the lead content of red. There's nothing low about low-lead. You're not gonna kill it, it's a Lyco, plus at warm temps you're probably not even hitting 65% at that altitude due to DA (aka no red box issues regardless of mixture). But I think you will continue to encounter valve related difficulties going forward if you operate at 100+ ROP during cruise long-term. Takeoff and climb is probably a good place for ROP ops. During cruise, you may try and dial that red knob back to peak EGT. Who knows, you might grow to like it :D

Glad you got the bird home. Nothing I hate more than getting stranded off-station (knock on wood so far so good). Good luck!
 
So you would run at peak EGT?

I understand 50 deg ROP is a bad place to run, but lots of people suggest 100 degrees ROP to be safe. On my carburated engine, not all cylinders are going to have the same mixture so if I lean it out then it is likely that some will be in the 50 deg ROP range, right?
 
So you would run at peak EGT?

I understand 50 deg ROP is a bad place to run, but lots of people suggest 100 degrees ROP to be safe. On my carburated engine, not all cylinders are going to have the same mixture so if I lean it out then it is likely that some will be in the 50 deg ROP range, right?
At 10K and +10 degrees standard there is no "red box" to worry about. Sixty-five percent power is an area where both Lycoming and Continental agree the engine cannot be damaged with the mixture knob.
 
I wasn't sure the engine would keep runnig ...
That is one of the best assumptions you can make in case of engine emergency. Do not ever assume you can make it on remaining engine power, you might be unpleasantly surprised.
Good job and the first one is behind you now.

Did you do any troubleshooting in the air? Checklist for rough running engine? The more troubleshooting and information you can provide to the mechanic, the easier it is for him to tell what failed.
(example: when I lost a cylinder in flight, I collected some engine monitor numbers for different power settings and when I told the mechanic, he diagnosed the problem immediately just from my input, without even looking at the engine - knowledge is power)
 
Did you do any troubleshooting in the air? Checklist for rough running engine? The more troubleshooting and information you can provide to the mechanic, the easier it is for him to tell what failed.

Once the cylinder went cold, I didn't do much troubleshooting. I was hand flying in IMC, still had to cross a ridge of mountains and find the airport. Getting to VMC over the airport was my only concern at that point. Had it been a perfect VMC day in the same place, I think I would have spent more time trying to figure it out.
 
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