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Fuel Issues...I think


JRam

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After looking at the Savvy data I would think water could have been the problem.  It looks to me that you need to have the red EGT cylinder looked at.  Injector nozzle may need to be cleaned or upper deck pressure might be leaking.  It could also be a valve.   On the water issue you may need to change O rings on the gas caps and you need to determine if the holes in the ribs are open.  I do not think you need to open the tanks but you need an A&P with Mooney experience to look this over throughly.  

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If I have this right... 

It is nearly a two hour flight...

Speed oscillations were pretty strong Starting in the second hour...

Looking at the Savvy chart at the 1:05 mark... the EGTs are showing an interesting movement... not consistent with steady power output...

As if the MP was adjusted...

combining the JPI data and the flight tracker data they seem to be from the same flight...

See if you can confirm seeing the EGTs significant move from the steady lines in cruise for 10 minutes. Then the lines return again to the power level before... (sort of).

If you didn’t adjust power to make these lines stray from their nice flat lines... something caused what looks like a significant power reduction...

Compare to previous flights you have had... See any changes like you have here? Or is cruise alway straight line EGTs...

If MP is self adjusting... you may have a turbo or controller challenge...

Confirm that you are seeing the anomaly of EGTs at 13:05 time mark that lasts for nearly 10 minutes, before nearly recovering to the end of the cruise portion of the flight...

Not am I only a private pilot, I don’t have any turbo savvy data experience...

Adding to your experience...follow the line marked IAT... Induction Air Temp... That is showing some pretty unstable behavior...  when I would be expecting stability...

best regards,

-a-

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Strong downdrafts or mtn wave can definitely make your airspeed change that much as the autopilot corrects.  They can also be felt much higher than you were flying.  However, hitting a strong downdraft and having an engine problem on the same flight sounds pretty unlikely.  Too coincidental.

Gliders get up into the 30s and 40s near the Sierras and Rockies.  No kidding.  It’s mighty cold up there with no heater too! :ph34r: Mtn waves can be much higher and a very long way from mountains.

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JPI time line...

0:00 engine start... (EGTs And CHTs climb)

0:10 run-up?... (EGT activity)

0:15 T/O run ... strong climb of EGTs..

0:16 - 0:34 climb? 

0:35 power adjust and leaning for cruise...

0:45 - 1:04 nice stable data, EGTs and CHTs, and IAT....

1:05 The anomaly appears... IAT has a strong drop as if the turbo isn’t compressing air causing the IAT to not be hot. It falls rapidly...

watch the behavior of that IAT line it should be pretty stable, and heated... unless an intercooler is mis behaving...

If intercoolers worked that well, they would be much smaller and lighter weight....

Bring your data to your mechanic... I think you may have found a power issue.

But, if the turbo drops off-line... the MP also does too... did you not see the MP change? The throttle didn’t move, but expect that the MP was dropping out as well...

Compare this  flight to all of your previous flights... see how stable the IAT line has been behaving... if this is the first time that line has dropped out... it is a sign of good data, showing a turbo related problem...

Wish I had better experience to share. I could be completely off target with these observations.

Still only a PP and not a mechanic...

Best regards,

-a-

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5 hours ago, carusoam said:

 

Wish I had better experience to share. I could be completely off target with these observations.

Still only a PP and not a mechanic...

Best regards,

-a-

Hahaha ha

First understatement of 2019

:)

Edited by Mcstealth
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6 hours ago, carusoam said:

Compare this  flight to all of your previous flights

I'll process all this today and pull my other flights to see if I'm experiencing it on others. I did not notice MP drop at all and when this happened (at least 3 times) I was checking out everything. Although possible I had an MP drop and by the time I was looking it had returned.

Because my fuel flow meter reading is (and has been for a while) inconsistent, I watch the temps and throughout the flight make adjustments as necessary. I fly LOP at 2500 RPM, 32" MP and 10 gph which usually gives me very low temps (1500 TIT, 290-320 CHTs throughout the flight). 

My wife swears we weren't over the mountains when we had the sputter. I can verify we were less that 10 miles SW from Charlottesville because we had that chosen as our emergency landing spot. So we definitely had some smaller mountains around us.

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Ok, I am an idiot. I posted the wrong Savvy Data. It all made sense to me...until it didn't. Here is my actual data from yesterday:

159702675_FlightAVL-HEF.thumb.png.d81ac50c1a72ea46fc484cd5c458eeb3.png

I included Oil in the bottom graph as well. This next one was a perfect flight from DC to Asheville which is what I consider "Normal"611850871_FlightHEF-AVL.thumb.png.041aaa36b3010998175698279b983378.png

I believe this was my timeline for the flight in question (To the best of my memory) all times CST:

11:50 - Startup
12:00 - Runup
12:02 - Departure - start of climb

12:13 - Start of cruise, reduce MP to 26", RPM to 2450, start lean procedures on 700 to find lean point, bring MP back up to 32" and RPM to 2500.
12:45ish - Switch to right tank (not 100% sure when I did this)
13:02 - Reduction in speed ~27KTS (https://flightaware.com/live/flight/N57241/history/20190101/1730Z/KAVL/KHEF/tracklog) - Matches drop in temps at 01:13 - Location: https://www.google.com/maps/place/37°19'04.1"N+79°52'27.8"W/@37.2023163,-79.6361757,9z/data=!4m5!3m4!1s0x0:0x0!8m2!3d37.3178!4d-79.8744
13:10 - Reduction in speed ~ 40KTS - Matches another drop in temps at 01:20 - Location: https://www.google.com/maps/place/37°32'45.6"N+79°32'12.5"W/@37.6041784,-79.6208192,10.38z/data=!4m5!3m4!1s0x0:0x0!8m2!3d37.546!4d-79.5368
13:25 - Reduction in speed by ~33KTS - Matches drop in temps at 01:36 on Savvy graph - Location: https://www.google.com/maps/place/37°59'20.4"N+78°52'07.0"W/@37.998741,-78.9605766,11.13z/data=!4m5!3m4!1s0x0:0x0!8m2!3d37.989!4d-78.8686
13:30 - Reduction in speed by ~50KTS - Matches drop in temps at 01:41 on Savvy graph - I believe this is where my engine sputtered Location: https://www.google.com/maps/place/38°10'56.3"N+78°35'01.0"W/@38.1571424,-78.6587757,11.75z/data=!4m5!3m4!1s0x0:0x0!8m2!3d38.1823!4d-78.5836
13:30 - Switch back to left tank
13:32 - Begin decent to 6000
13:42 - Begin decent to 2000
13:54 - Land

A couple things I noticed.
1.) While each time my speed dropped, I was near a range, I would have expected mountain effect at many other times during the flight much more than those.
2.) Each drop in speed resulted in a drop in temperature but also a slight increase in rate of climb (30ish feet per minute) per my ADS-B logs.

Also, I had a tailwind of around 40KTS throughout the flight
 

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Used to fly Charlotte to Allentown, PA every 6 weeks or so.  When the wind was directly 250-270 I would sometimes experience down drafts from Lynchburg to Montebello.  Smooth ride but airspeed would drop as much as 60 knots to stay at 9000.  Once, it was so pronounced, so prolonged, I too thought there was an engine problem.  The FT-101 will sometimes give a low reading, recover, quit when going bad.  Time for another Floscan transducer. 

There was a thread on Beechtalk a week ago regarding mountain waves in the same area. People seem to think that stuff is reserved for the big mountains out west.

Edited by David Lloyd
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 I’ve made the flight from Asheville to my home base outside of DC several times. Mountain waves in the area can be brutal. I’ve actually had to ask for block altitude to avoid frightening passengers. Being at full power max RPM and watching the IAS head south of 100 and the VSI  showing -1200fpm is no fun.  Surfing the updraft on the other side is usually a lot more fun. However, I’ve also been in situations where I have to make large power reductions to simultaneously stop the climb and stay under VNE.   Having not been there it’s really difficult to figure out what happened.  I will say that I consider bad or contaminated fuel to be a low probability in general.

Edited by Shadrach
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Hate to say this, but.....First time I was in the same situation over the mountains in Colorado, speed dropped, scanned my instruments, listened more carefully to the engine, which I swear was sounding rough, with a beat I may not have heard before, perhaps a 'sputter'? No digital instruments then. If all other indications besides temps were good, I would consider flying cautiously until I was sure if it was something mechanical or perceptual. 

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Mountain waves on the lee side...

With an AP, you get scared because your speed drops off precipitously.... pretty scary.

  • Its not obvious what is happening because the AP doesn’t tell you what it is doing... and not doing...
  • PIC: Add or remove power to maintain speed, in THIS case.

 

Without an AP, you get scared because your altitude drops off precipitously.... pretty scary.

  • But, you get the primal hint to add power pretty quickly...
  • PIC: Add power or remove power to maintain altitude...

 

Doing it in the dark or at lower altitude is icing on the cake....

 

There are probably a few lessons to be learned about best ways to use an AP and other things to watch out for... run-away trim is one of the baddies...

PP thoughts only, not a CFI...

Best regards,

-a-

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Pretty good mountain wave going on today around the Appalachian’s. Winds at 9000 from the west-northwest at 50kts. The ridge waves show up pretty good on the satellite imagery on my ForeFlight. Couldn’t see it at the time but sure could feel it. A little bumpy in the front range today. 

6960400A-278D-49E0-85C8-F68206E26748.gif.303884afb761d91a7362b2841647bc08.gif

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