17,000 in an M20F

[FloridaMan]

I was seeing about 300fpm when I stopped climbing at 17,000ft. It was cold outside. My trim wheel was freezing. The handling of the airplane at that altitude felt weird and I swear I'd hear the engine misfire here and there. I was afraid that something weird was happening with either the fuel system or my own engine management. Also, the physiological effects on my body were something that I had never experienced. I may have been a little dehydrated and I didn't get a full night's sleep to begin with. I was on oxygen and my pulse oximeter showed me at 92, but my heart rate was over 100 and I felt very anxious, was unable to think clearly and felt confused so I dropped back down to 11,000. I have a feeling that I may have been mismanaging my oxygen by not sucking enough through the cannula and perhaps I should've used the mask instead. 

 

[jetdriven]

It's 17,000 not a FL. Those begin at FL 180 or FL190

But nonetheless still pretty impressive u got it up that high.

[FloridaMan]

It's 17,000 not a FL. Those begin at FL 180 or FL190

But nonetheless still pretty impressive u got it up that high.

 

Next trip I think the plane can get there. I was still 25-30 mph over Vy at 17,000 and I may have been able to trade it. I didn't like the way things felt or sounded to me so I came back down. 

[Mooneymite]

It's 17,000 not a FL. Those begin at FL 180 or FL190

 

 

Depends on where you are!

 

I've flown at FL 060 many times....

[NotarPilot]

You must've had some tailwind up there. Airspeed shows just over 100 knots but Dynon shows 172 knots. Nice!

[Danb]

Antaresthats impressive.,even though you were reading 92 on the oximeter try to stay at or above 95% also monitor it frequently if you breathed through your mouth you may have been a little hypoxia at times even though it showed 92%. If you drive that high more think about having another oximeter with you. Mooney builds great planes...

[Mooneymite]

but my heart rate was over 100 and I felt very anxious, was unable to think clearly and felt confused so I dropped back down to 11,000.

 

Well, I'd say you were thinking pretty well....That was an excellent decision!

[piperpainter]

Just make an effort to breath from your nose and you'll be good next time. I sometimes have to put extra though into breathing through my nose with the canula. If you use the mask it goes through oxygen super fast! Use the Canuala but make that effort to breath! 

[WardHolbrook]

You probably weren't imagining the occasional misfire. Many turbocharged aircraft utilize pressurized magnetos to stop it from happening.

[kortopates]

I am sure it was just a bit of anxiety. 92% is fine. But a mask will it make it easier to maintain saturation.You may very well have been hearing the engine missing though since our turbo aircraft use pressurized mags, but then again 17K is not at all uncommon for an Ovation with out pressurized magnetos - so really shouldn't be an issue till in the FL's.  

[Jim Peace]

Next trip I think the plane can get there. I was still 25-30 mph over Vy at 17,000 and I may have been able to trade it. I didn't like the way things felt or sounded to me so I came back down. 

What is your Vy at 17,000 feet......? What is your Vx?  Are you using the numbers for Sea level in the POH? do they give a chart or correction figure to use at 17,000?

[FloridaMan]

There's a chart for Vy. IIRC, it's 113 mph - 1mph per 1000ft

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[Lood]

Wow, amazing! I never thought our old F's would actually manage 17k ft, still climbing. Just for interest sake, what fuel flow were you seeing up there?

[Hank]

I took my C to 15,000 indicated one hot summer day. Wrote down everything, did some research and calculating, DA was 18,600. Climb was anemic, controls were mushy, but it was cool just to be able to do it. It was logged as an oxygen checkout. Then we practiced emergency descents on the way back down--Vne and fast spirals.

For what it's worth, Vy in my C is 100 mph - Altitude in thousands, down to 90 mph at 10,000 msl. Not sure if the book shows Vy above that, although the climb chart goes to 18,000 I think. Need to look that up, it's been several years. I don't have the need to go to oxygen levels . . .

[jnisley]

This fall on a cross country from Iowa to Pa I took my turbo-normalized M20F to 17,000 and it occasionally missed, I noticed my fuel pressure needle fluctuating, turning on the boost pump took care of the missing of the engine but not the missing my heart:(, descending to 15,500 didn't solve it so I descended to 13,500 which solved it. Earlier this summer I took it up to 17,800 (actually 18,300 briefly) and it didn't miss at all so I'm not sure what changed.

[N201MKTurbo]

When I first bought my M20F in 1984 I lived in Denver. I occasionally crossed the continental divide at 16500 and a few times crossed IFR at 16000 (MEA). Other then being a little slow it ran just fine and didn't fly any different then at any other altitude at the same airspeed.

[DS1980]

There's a chart for Vy. IIRC, it's 113 mph - 1mph per 1000ft

 

For non turbocharged I believe. Vy and Vx change due to a decrease in power available.

[EDNR-Cruiser]

Difference between IAS and TAS is 2% per 1000 ft change in altitude, OAT also has an impact on TAS vs. IAS but at 17.000ft the TAS is roughly 34% higher than IAS, so TAS should be around 134 kts and the tailwind factor then reduces to just 38 kts.

Some aircraft have problems to ensure a stable fuel supply to the engine above 16.000ft due to low air pressure. It might help switching the electrical fuel pump on next time you feel the engine runs unstable above 15.000ft...

[JackShowers]

Fun topic....

 

    My M20F did pretty good at 17,000, too.... climbing 200-250 fpm.  Lood, she was using 8.2 or 8.1 GPH. 

 

    Antares, I think you can certainly get to 20,000 if you've got the time.  Back in the early 2000's there was a guy who posted (on "The List") an attempt to get over the Front Range against winds in a C model, as well as a few other trips up high....  I don't remember it all that well, but I do know he mentioned having been to FL210 at some point or another, or got close.  A couple of other guys claimed they had been over 20,000 in NA Mooneys, IIRC.

 

    I also once experienced some anxiety and thought it was anoxia, but the oximeter read good numbers in the high 90's, so I stuck with it and calmed down.  On one of the trips I left Aspen and flew at 17000 to Ardmore (delivering it to Maxwell for an annual).

 

    Big fun.   Thanks for letting me butt in.

 

                                     Jack

[M20F]

I have a TN M20F and after about FL210 the controls get real sloppy. I can get 65% to 17000-Fl180 depending upon the day so could probably push into FL270-280 if I wanted. Highest I have been is FL230 and to be honest anything really above FL190-20 is diminishing returns, just don't get enough TAS for the manifold you give up.

[Marauder]

I have a TN M20F and after about FL210 the controls get real sloppy. I can get 65% to 17000-Fl180 depending upon the day so could probably push into FL270-280 if I wanted. Highest I have been is FL230 and to be honest anything really above FL190-20 is diminishing returns, just don't get enough TAS for the manifold you give up.

 

What kind of airspeeds are you seeing above 14k? I have been up to 16k a couple of times (years ago) and I just remember the controls feeling like I was flying a Cessna 172. 

[jnisley]

Here's a flight I did this past June, the controls were somewhat mushy but not uncomfortably so.

17,800' level flight

MP 24.5 (waste gate fully closed, mechanic has since adjusted waste gate, it wasn't closing completely)

RPM 2500

FF 11gph (I needed this flow to keep cylinders in a decent range)

IAS 143MPH

TAS 195MPH

GS 171MPH

Oil temp 194 degrees

OAT 22 degrees F

#1-316 1407, #2-388 1270, #3-375 1377, #4-328 1405

[EDNR-Cruiser]

@Marauder:
Doesn't matter how his Mooney feels as he is flying a turbo-normalized engine which can go much faster than a normally aspirated M20F up there! As his MP and speeds are much higher above 10.000 ft, his controls will also feel differently than yours or mine at altitude.
With a turbo normalized IO-360 you may still see 145 mph or more in 17000 ft wheras a standard M20F may only show 110 mph IAS... - and then the controls feel mushy indeed. You can easily try this at lower altitudes at all times if you just throttle back to 110 mph IAS...

[FloridaMan]

I was showing 120-125 (I snapped that pic as soon as I leveled off lest something happened that made me descend). I do get an extra prop pressure bump with the lopresti cowl, but I think that I closed that when it misfired. I've noticed that my control surfaces are much smoother than the corrugated surfaces of the later J and K models and wonder if that has anything to do with yaw stability. 

[RobertGary1]

I'm not sure if the physical affects you describe are typical. I've not noticed those in the unpressurized T-206H in the mid 20's. The Mooney has about the most attitude capability of anything I've flown non-turbo. I often go to 16,500 crossing back over the Sierras. You can ride the mountain waves on the way up so its not such a struggle.

 

-Robert