The M20F Performance Benchmark thread.

[Shadrach]

I hope to see this thread turn into a repository of real world performance data for the Mooney M20F (happy to see separate threads started for other models).  It would be helpful for new and potential owners to know what is typical of each model.  I will be periodically adding performance data and I hope others will as well. As I acquire new data, some posts may be edited with the goal of minimizing clutter and duplicative information.

With the introduction of ADSB data we can now see hard data rather than wishful thinking. To that end, it would be helpful if ADSB track, weather conditions and aircraft weight were included in any posts to give a complete and accurate analysis.

Summery of entries:

Average Time to climb 2150lbs

10,000

1065 FPM

850 FPM

 

Average Speed ROP

10,000

147.5KTS

 

Average Speed LOP

10,000

142.5KTS

 

[Shadrach]

This was a quick time to climb flight conducted at a calculated weight of 2136lbs or 604lbs under MGW (pilot, 35gal, 6qts oil and 20lbs of random crap in the baggage compartment).  

Weather Temp 60 °F DP 32 °F  RH 35% Wind SSE14 mph Baro 29.65 in 

DA was 600ft at a 701 field elevation. Pretty close to a standard day.

It was bumpy and I think I could have done a better job with speed management, which is likely the cause of the significant ROC decrease after the first 1000'. Nevertheless, >1000fpm through 7000 isn't bad. Total time to ascend from 1025 to 10,025 was 8 minutes and 27 seconds which works out to an Avg ROC of 1065. 

Speed runs are coming soon.  I will be taking some 45lb plates to the hangar to get data at higher weights.

The reason that the climb interval altitudes are not exact round numbers is because there was not data for that specific anltitude available.  In such cases, I took the closest altitude for which data was provided.

[Ragsf15e]

I sort of doubt we’ll be able to see a difference, but it might be nice to include significant alterations to the airplane (TN , io-390, weight definitely need documented).  Are you 2 blade prop, stock cowl and windscreen?

I’ll try for a similar weight climb test, but it looks like you beat me by a little and I’ve got a 201 windscreen and 3 blade prop…

Edited April 28, 2024 by Ragsf15e

[Shadrach]

2 minutes ago, Ragsf15e said:

I sort of doubt we’ll be able to see a difference, but it might be nice to include significant alterations to the airplane (TN , io-390, weight definitely need documented).  Are you 2 blade prop, stock cowl and windscreen?

I’ll try for a similar weight climb test, but it looks like you beat me by a little and I’ve got a 201 windscreen and 3 blade prop…

Mine is a time capsule that is close to how it was delivered from the factory. It’s going to take several data sets to draw meaningful performance conclusions.

[Ragsf15e]

On 4/27/2024 at 7:37 PM, Shadrach said:

This was a quick time to climb flight conducted at a calculated weight of 2136lbs or 604lbs under MGW (pilot, 35gal, 6qts oil and 20lbs of random crap in the baggage compartment).  

Weather Temp 60 °F DP 32 °F  RH 35% Wind SSE14 mph Baro 29.65 in 

DA was 600ft at a 701 field elevation. Pretty close to a standard day.

It was bumpy and I think I could have done a better job with speed management, which is likely the cause of the significant ROC decrease after the first 1000'. Nevertheless, >1000fpm through 7000 isn't bad. Total time to ascend from 1025 to 10,025 was 8 minutes and 27 seconds which works out to an Avg ROC of 1065. 

Speed runs are coming soon.  I will be taking some 45lb plates to the hangar to get data at higher weights.

The reason that the climb interval altitudes are not exact round numbers is because there was not data for that specific anltitude available.  In such cases, I took the closest altitude for which data was provided.

How's you get the pretty table for your climb?  Did you make it yourself or is there some way to export off adsb exchange?

[Ragsf15e]

https://globe.adsbexchange.com/?icao=a4be6e&lat=47.625&lon=-117.353&zoom=11.8&showTrace=2024-05-03&timestamp=1714757520

That should link to the flight.  I did a timed climb at 105 mph indicated from 2000' field elevation to 10,000'.  DA at takeoff was 3121'.  Weight was 600lbs below MGW, about 2140lbs (pilot, some junk in the back and 30 gallons fuel).  Initial climb was ~1100fpm, 2000-6000' in 4:20" (~925fpm average).  6-8000 in 2:15 (~890 fpm).  8-10,000 in 2:50 (705 fpm).  Overall, 2000'-10000', ~850fpm.  I have a 3 blade prop and a 201 windshield, but otherwise stock.  Having owned it for 10 years, it's always been a bit slower than I see others claim, so it won't surprise me to see climb a bit less than others.  Although I started from 3000' DA instead of sea level like @Shadrach, so I lost out on the higher climb rates down low helping my average.

Then I did LOP and ROP speed runs at 10,000'.  Here's the chart I use.  I get groundspeed in each cardinal direction and then put that into a TAS computer when I get back home (https://www.eaa62.org/technotes/speed.htm).  You can just take the average of the 4 way and get close, but it won't be correct as it will always indicate slightly higher than truth based on the wind drift (headwind and tailwind are taken out with the average but sideways isn't).  Depending on winds, average of the 4 directions is within about 1 knot (it will always be higher than truth).

These are 10,000', -7C, light airplane, relatively forward CG:

So LOP, I get 142.5 KTAS

And ROP, I get 147.5 KTAS

[Shadrach]

24 minutes ago, Ragsf15e said:

How's you get the pretty table for your climb?  Did you make it yourself or is there some way to export off adsb exchange?

I did it in excel. I had to enter the data manually but was above to pull the formula for ROC from top to bottom using the fill handle. 

[Shadrach]

2 minutes ago, Ragsf15e said:

https://globe.adsbexchange.com/?icao=a4be6e&lat=47.625&lon=-117.353&zoom=11.8&showTrace=2024-05-03&timestamp=1714757520

That should link to the flight.  I did a timed climb at 105 mph indicated from 2000' field elevation to 10,000'.  DA at takeoff was 3121'.  Weight was 600lbs below MGW, about 2140lbs (pilot, some junk in the back and 30 gallons fuel).  Initial climb was ~1100fpm, 2000-6000' in 4:20" (~925fpm average).  6-8000 in 2:15 (~890 fpm).  8-10,000 in 2:50 (705 fpm).  Overall, 2000'-10000', ~850fpm.  I have a 3 blade prop and a 201 windshield, but otherwise stock.  Having owned it for 10 years, it's always been a bit slower than I see others claim, so it won't surprise me to see climb a bit less than others.  Although I started from 3000' DA instead of sea level like @Shadrach, so I lost out on the higher climb rates down low helping my average.

Then I did LOP and ROP speed runs at 10,000'.  Here's the chart I use.  I get groundspeed in each cardinal direction and then put that into a TAS computer when I get back home (https://www.eaa62.org/technotes/speed.htm).  You can just take the average of the 4 way and get close, but it won't be correct as it will always indicate slightly higher than truth based on the wind drift (headwind and tailwind are taken out with the average but sideways isn't).  Depending on winds, average of the 4 directions is within about 1 knot (it will always be higher than truth).

These are 10,000', -7C, light airplane, relatively forward CG:

So LOP, I get 142.5 KTAS

And ROP, I get 147.5 KTAS

Great data! The speed is almost exactly what I would expect with a three blade.  I will be doing some speed runs as soon as we get some decent weather. 

[RescueMunchkin]

Are you assuming climb at Vy? I usually can't do a straight climb because of airspace shelves but have been doing cruise climbs targeting 500fpm when I want higher.

[Shadrach]

1 hour ago, RescueMunchkin said:

Are you assuming climb at Vy? I usually can't do a straight climb because of airspace shelves but have been doing cruise climbs targeting 500fpm when I want higher.

So far these have been timed climbs to 10K. I am trying to maintain calculated Vy. I think I failed a bit as my climb rates did not fall off in a linear manner.  Practice makes perfect. I will keep trying.
will add a three way speed run next time.

[Ragsf15e]

1 hour ago, RescueMunchkin said:

Are you assuming climb at Vy? I usually can't do a straight climb because of airspace shelves but have been doing cruise climbs targeting 500fpm when I want higher.

I have class C above me too, but I can almost always get cleared through it before I have to level off to stay below.  So I did one a few months ago at published Vy and now I’ve done it twice at 105mph which is about 5mph slower and my rate is better.  My engine temps have been fine, but it’s pretty cold up here still.

[Ragsf15e]

2 hours ago, Shadrach said:

Great data! The speed is almost exactly what I would expect with a three blade.  I will be doing some speed runs as soon as we get some decent weather. 

We’ll have to try to get a few different altitudes.  I usually fly 8-10k up here but I’ve seen the best speeds around 6,000’.

[802flyer]

I recently did a max performance climb to 9000ft with a takeoff weight just shy of 2300lbs, 50F, 30.48. Mods include the SWTA windshield and cowl, aileron/flap gap seals, wing/tail root fairings.  2 blade prop. I have the twisted wing, for what that’s worth.
Average climb rate from start to end: 1164 FPM
First thousand (1K-2K): 1315 FPM
Middle of climb (3.5-6K) 1250 FPM
last 1500' of climb 984 FPM
Looking forward to collecting/adding more data, especially on westbound legs where I can go with the 10k benchmark (or eastbound that justify going above 10k).

[802flyer]

I had previously posted this in another thread:

Takeoff weight around 2350lbs and temp on the ground around 30F.

I was not as aggressive with the climb airspeed, starting off at my typical 120mph and slowing gradually to 100mph as I got to the end of climb.

Started a timer entering the runway and it had just ticked over 15min as I cleared 12,000ft. So about 750fpm average (corrected for field elevation of 780).

Next time, I’ll have to try the more aggressive deck angle at 100mph.

[Matt Lundquist]

All,

 

Any real world application for Takeoff and Landing performance above the Mooney M20F POH limit of 5000? I have a few buddies in the Colorado Springs area and want to kind of get a gauge of performance? Thank you in advance

 

Matt

[Vance Harral]

33 minutes ago, Matt Lundquist said:

Any real world application for Takeoff and Landing performance above the Mooney M20F POH limit of 5000?

Not sure what version of the M20F POH you're looking at, but the 1975 edition has takeoff and landing data up to 7500' at 70 degrees F, which is about 10,000' DA.  Takeoff distance chart is pasted below, landing distance is shorter than takeoff distance for all cases.  Real world performance of any stock, airworthy M20F is not meaningfully different from these numbers.

 

[Ragsf15e]

9 hours ago, Matt Lundquist said:

All,

 

Any real world application for Takeoff and Landing performance above the Mooney M20F POH limit of 5000? I have a few buddies in the Colorado Springs area and want to kind of get a gauge of performance? Thank you in advance

 

Matt

Matt,

Hopefully your flight home went well!

One recommendation for departing at high altitudes (ok, maybe two)

1. Only take the weight you need, so 40 gallons of fuel is much better than 64 if you’re going to make a fuel stop anyway.  Weight is key.

2. During the early takeoff roll, adjust the mixture to ~1220 egt (they are all a little different, but pick one).  That’s roughly your max power, climb mixture setting.  If you’re leaner than that, it’s very easy to get hot CHTs very fast during takeoff and initial climb.  Richer than that is less power.

The F does well at Colorado altitudes, but I always tried to leave by ~11am or earlier in the summer.

[Matt Lundquist]

On 1/18/2025 at 8:12 PM, Ragsf15e said:

Matt,

Hopefully your flight home went well!

One recommendation for departing at high altitudes (ok, maybe two)

1. Only take the weight you need, so 40 gallons of fuel is much better than 64 if you’re going to make a fuel stop anyway.  Weight is key.

2. During the early takeoff roll, adjust the mixture to ~1220 egt (they are all a little different, but pick one).  That’s roughly your max power, climb mixture setting.  If you’re leaner than that, it’s very easy to get hot CHTs very fast during takeoff and initial climb.  Richer than that is less power.

The F does well at Colorado altitudes, but I always tried to leave by ~11am or earlier in the summer.

Thank you for the advice. By chance any nerd math. Like with 40 gals and that setting the 1220 egt, you get a takeoff roll of X and a total takeoff distance of Y? For a given altitude and temp like 7000K and 20C

[Ragsf15e]

20 minutes ago, Matt Lundquist said:

Thank you for the advice. By chance any nerd math. Like with 40 gals and that setting the 1220 egt, you get a takeoff roll of X and a total takeoff distance of Y? For a given altitude and temp like 7000K and 20C

Well, I can get close to the nerd math for you!  On the back of my old checklist in the airplane theres a Koch chart.  You can use that to scale your takeoff data from sea level to whatever altitude/temp combo you want.  This explains it with an example.  I used it to give me an idea of how much DA effect to expect and I found it reasonable but maybe slightly overestimating the effect.

https://learntoflywithkris.com/koch_chart.html

[Vance Harral]

The Koch chart is fine, but the "nerd math" you're asking about is right there in the performance data from the POH I posted.  You just have to interpolate.  Compute takeoff weight with your particular load (including fuel) and interpolate between the 2300 and 2740 data points, then note the temperature at the selected pressure altitude and interpolate between the temperature points.  Or vice-versa, you can start on either axis.  At the risk of sounding like a jerk, this is basic private pilot stuff.

Regarding mixture setting vs. performance, yes you need to lean appropriately for the DA, and target EGT is a fine way to do so.  But note that the curve of power developed vs. mixture setting is pretty flat across its peak.  Per the graph below, in the max power rage, differences of 200 degrees EGT only change the power developed by a few percent.  So you're not going to see any meaningful difference in takeoff distance and climb rate by getting the mixture setting "perfect" vs. "good enough".  This seems to be widely misunderstood, and I fly with lots of pilots who I think spend way too much time fiddling with the mixture during runup at higher DAs in normally aspirated airplanes.  Set the mixture "pretty rich" just prior to runup; lean it promptly past peak RPM to roughness; then move it back to about peak plus roughly 1/2" of travel, and you're done.  Takes about 5 seconds.  If 2% power is the difference between clearing and hitting terrain, that's a judgement problem in deciding to take off in the first place, not a problem with leaning technique.

 

[MikeOH]

^^^ THIS ^^^

Truth is, you can pretty much 'feel' the power as you go from too rich to too lean...and the range of the mixture setting where the 'pull' you feel is good, is pretty broad.  At the DAs of concern you don't have to worry about the red-box (talking non-turbo!), so you can move back and forth from rich to lean without concern.  After finding the 'sweet spot' I glance at the EGTs and check they're 1200-1300; sea level temp for me is about 1250.  As you say, takes maybe 5 seconds.

[Ragsf15e]

3 hours ago, Vance Harral said:

The Koch chart is fine, but the "nerd math" you're asking about is right there in the performance data from the POH I posted.  You just have to interpolate.  Compute takeoff weight with your particular load (including fuel) and interpolate between the 2300 and 2740 data points, then note the temperature at the selected pressure altitude and interpolate between the temperature points.  Or vice-versa, you can start on either axis.  At the risk of sounding like a jerk, this is basic private pilot stuff.

Regarding mixture setting vs. performance, yes you need to lean appropriately for the DA, and target EGT is a fine way to do so.  But note that the curve of power developed vs. mixture setting is pretty flat across its peak.  Per the graph below, in the max power rage, differences of 200 degrees EGT only change the power developed by a few percent.  So you're not going to see any meaningful difference in takeoff distance and climb rate by getting the mixture setting "perfect" vs. "good enough".  This seems to be widely misunderstood, and I fly with lots of pilots who I think spend way too much time fiddling with the mixture during runup at higher DAs in normally aspirated airplanes.  Set the mixture "pretty rich" just prior to runup; lean it promptly past peak RPM to roughness; then move it back to about peak plus roughly 1/2" of travel, and you're done.  Takes about 5 seconds.  If 2% power is the difference between clearing and hitting terrain, that's a judgement problem in deciding to take off in the first place, not a problem with leaning technique.

 

I much prefer the target egt method vs what you describe as long as you have an engine monitor.  Yes, I agree that you’ll get roughly the same power output , but if you end up leaner than you intended, you can very quickly get very hot CHTs.  Slow speed, warm day, high altitude, thin cooling air, initial takeoff/climb.  It’s a busy time when you don’t want to look down and deal with 450 degree chts.  Target egt is a better, known setting.  Yes, it doesn’t have to be perfect.

[Vance Harral]

42 minutes ago, Ragsf15e said:

but if you end up leaner than you intended, you can very quickly get very hot CHTs.

Nah, not with a correctly functioning engine at high DA.  That chart I posted shows the effect of CHT with leaning, it changes by about 10C (roughly 20F) across the "max power" band of mixture settings.  A difference of 20 degrees CHT during initial climbout isn't going to destroy a correctly functioning Lycoming, particularly not on departure from a high DA airport in a normally aspirated airplane where you're making considerably less than the full 200hp.  If your stock M20F hits 450F CHT during climb out from a 5000' airport - even in the middle of summer - the mixture setting is not the problem.  Something is seriously wrong with the engine or the baffling.

That doesn't make the target EGT method "wrong", but I think you're over-emphasizing the importance of it on takeoff.  It's not a critical number on the takeoff roll or the first 1000' of climb, and it's therefore arguable whether it's worth the distraction of looking at it during a critical phase of flight.  It's not so much that it's a huge risk to take a glance, and maybe even tweak the mixture knob based on what you see.  But doing so doesn't result in a meaningful difference in performance or safety, so why bother?  Ignoring EGT details during this time gives you a few more seconds and neurons to look at things that matter more - like the actual CHTs, which could be the earliest indicators of a problem unrelated to mixture setting, and therefore should be monitored anyway (along with oil pressure and temp).  You can glance at the EGT and make a mixture tweak later, at 1000' AGL and about every 1000' thereafter.

[Ragsf15e]

4 hours ago, Vance Harral said:

Nah, not with a correctly functioning engine at high DA.  That chart I posted shows the effect of CHT with leaning, it changes by about 10C (roughly 20F) across the "max power" band of mixture settings.  A difference of 20 degrees CHT during initial climbout isn't going to destroy a correctly functioning Lycoming, particularly not on departure from a high DA airport in a normally aspirated airplane where you're making considerably less than the full 200hp.  If your stock M20F hits 450F CHT during climb out from a 5000' airport - even in the middle of summer - the mixture setting is not the problem.  Something is seriously wrong with the engine or the baffling.

That doesn't make the target EGT method "wrong", but I think you're over-emphasizing the importance of it on takeoff.  It's not a critical number on the takeoff roll or the first 1000' of climb, and it's therefore arguable whether it's worth the distraction of looking at it during a critical phase of flight.  It's not so much that it's a huge risk to take a glance, and maybe even tweak the mixture knob based on what you see.  But doing so doesn't result in a meaningful difference in performance or safety, so why bother?  Ignoring EGT details during this time gives you a few more seconds and neurons to look at things that matter more - like the actual CHTs, which could be the earliest indicators of a problem unrelated to mixture setting, and therefore should be monitored anyway (along with oil pressure and temp).  You can glance at the EGT and make a mixture tweak later, at 1000' AGL and about every 1000' thereafter.

I guess to each their own, but my engine baffles and cooling was solid, but im pretty sure being 50-100 rop on takeoff vs ~200 rop (which is roughly where target egt puts you) will make a much more significant difference.  I have flown to Mammoth last summer, Colorado recently, and routinely in the pnw.  I don’t think im imagining it.

[Vance Harral]

3 minutes ago, Ragsf15e said:

I don’t think im imagining it.

I'm sure you're not, but either your instrumentation or your engine or your baffling is amiss somehow.  There's no way a stock M20F departing from a Colorado airport should have any cylinder at 450F during a Vy climb, regardless of atmospheric conditions or where the mixture is set.  On the very warmest days in summer, our engine might be a few degrees over 400, briefly.  I've never seen anything remotely close to the factory redline of 460 in our airplane, or other E/F models I've flown in around here, for 20+ years.