Is there confusion with Vx on our vintage M20s?

[Nukemzzz]

So the crusty old owners manual that came with my 66E, that’s in a ziplock bag on the hat rack I’m fairly certain says 80mph for Vx. The latest revision of that manual, the one I made a binder for, says 94mph. I think the difference is the new manual is flaps up and the old is takeoff flaps. 

In a couple of weeks I’ll be asked by a DPE during my practical for my Vx and I’m struggling. I don’t think I like the flaps up Vx. Who gets gear and flaps up before 50’ AGL?   

I’m at risk of having this conversation with the DPE because it intrigues me. What do you guys use?  Am I thinking wrong here?  What would you say when asked. 

BTW, I have similar confusion on the Vbg. 107mph is what my manual says. I’ve seen around 90mph quoted for BG on an old Mooney advertisement for my plane before and I question this number as well. It’s range seems to be terrible at 107mph. 

[Rjfanjet]

My 68C says 80 with flaps and gear up. When I taught short field takeoffs, gear came up as soon as practical and flaps when clear of obstacle. What does your CFI say?

[Nukemzzz]

45 minutes ago, Rjfanjet said:

My 68C says 80 with flaps and gear up. When I taught short field takeoffs, gear came up as soon as practical and flaps when clear of obstacle. What does your CFI say?

Wait, so gear and flaps up?  I guess I need to fetch my og manual tomorrow to see what it says again. 

[PT20J]

Vx is the speed where there is maximum excess thrust available. It’s usually down around 1.1 Vs. I believe sometimes the manufacturer just picks a number with some margin above power on stall speed if the actual speed is too slow to be safe. @Blue on Topwould know.

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[Jerry 5TJ]

How about measuring the speeds yourself?   Then you have the actual indicated airspeeds and ROC for your plane.  Straightforward to then calculate the climb per mile for Vx.  

[N201MKTurbo]

I would have this conversation with the DPE and just decide on a number. All he is interested in is how precisely you can fly the plane. The actual number doesn’t matter as much as when and how well you hit and hold that number.

[Nukemzzz]

Sure seems like Vx would benefit from flaps. Not sure why they would call the number out clean as well. 

[Fly Boomer]

The DPE wants you to regurgitate the book number.

[PT20J]

This is something you should definitely work out during training before the practical test. The DPE’s role is to evaluate your skills, knowledge, and aeronautical decision making against the ACS standards. Asking the DPE what speed to use calls your knowledge, training and aeronautical decision making skills into question.

You should use a speed that you can defend. The final authority for speeds and procedures is the manufacturer’s handbook or POH/AFM for the make, model and serial number of the airplane. If a procedure isn’t described, the Airplane Flying Handbook procedure is the next best authority.

Generally, flaps increase CL for a given airspeed allowing for a lower liftoff speed and therefore shorter takeoff roll. Flaps also increase drag, so climb is usually better with flaps up. Recall that lift is a function of CL and airspeed squared. If you raise the flaps at a low airspeed, CL is reduced and the airplane climb angle will decrease. However, since airspeed has a greater effect on lift than CL, it doesn’t take a lot of extra airspeed to be able to raise the flaps safely. All this is the reason for holding Vx until clearing the obstacle and then accelerating to Vy before raising the flaps.

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[Vance Harral]

Is there confusion with Vx in our vintage M20s?  I say yes, absolutely.  Permit me to elaborate.

20 hours ago, Nukemzzz said:

So the crusty old owners manual that came with my 66E, that’s in a ziplock bag on the hat rack I’m fairly certain says 80mph for Vx.

I don't own an E model, but I sometimes give training in them.  I have a copy of the 1966-67 M20E "Super 21" Owner's Manual dated March 1967 for S/Ns 832-1308 and 67001-67062.  I don't see "Vx" or a "Best Climb Angle" speed published anywhere in that manual.  If someone can post a screen shot from that manual or a later M20E edition showing a published Vx, please do so.  Best as I can tell, Mooney simply didn't publish one for the M20E, and that's what I teach.  But I want to know if I'm wrong.

In any case, I do own a 1976 M20F model, and the October 1975 revision of the M20F Owners Manual has a Climb Performance table which charts both "Best Angle" and "Best Rate" climb speeds.  It claims the Best Angle speed is 94 MIAS/82 KIAS at all altitudes, while showing Best Rate to vary from 113/98 at sea level to 96/83 at 16K pressure altitude.  But... that chart has a Conditions section which says those speeds are with gear and flaps up.  In contrast, the Takeoff Distance chart specifies wing flaps in the takeoff position, and the "Normal Procedures" says not to raise flaps until clear of obstacles.  It also says not to raise the gear until you can do so safely, which obviously means at least the first few feet of takeoff occur with the gear down.  Conclusion: the chart in the M20F Owners Manual which specs a Best Angle climb speed isn't actually applicable to takeoff and obstacle clearance!

As a CFI, this leaves me with a dilemma in teaching proper short-field technique in vintage Mooneys.  While I don't necessarily claim it's the "one true way", I teach short field takeoff technique in vintage Mooneys with flaps set to takeoff and gear down until 50' AGL; then we raise the gear, then the flaps.  Using takeoff flaps matches what the Owners Manual prescribes.  My rationale for leaving the gear down thoughout the 50' climb is, during the roughly 6 seconds it takes to do this while pitched for Vx in that configuration, I want the pilot fully focused on pitch control, and spring-loaded to shove the nose down if the engine takes a holiday (or even hiccups).  Neither of those things is well served by taking one's hand off the throttle and trying to raise the gear, especially in a Johnson bar Mooney.

So what speed should one use for this 50' climb with gear down and takeoff flaps?  The M20F Owners Manual doesn't say.  Even if I changed technique to raise the gear "instantly", I still don't have a published Vx with flaps set to takeoff, which is what the manual prescribes until the obstacle is cleared.  Therefore, one has to determine Vx experimentally.  My partners and I have run this experiment several times in our M20F, and we find Vx with takeoff flaps and gear down at our home airport (KLMO, elevation 5050), is about 73 MIAS.  Yes, 73 MPH indicated.  Yes, that's uncomfortably slow.  Not only is it uncomfortably slow, it also requires an uncomfortably high pitch attitude and deck angle.  It really does achieve the shortest distance over a 50' obstacle, but it's a vulnerable configuration, and none of us like it.  When we practice true short field technique, we expect our students (and ourselves) to immediately lower the nose to a Vy climb attitude as soon as the obstacle is cleared.

Note: many pilots I work with on short field takeoffs hold Vx far too long.  The mythical 50' obstacle isn't much higher than the top of a tall hangar, and since you're going to be climbing in the neighborhood of 500 fpm, it only takes 1/10th of a minute to get there.  That's about 6 seconds.  By all means, clear the obstacle, but it hardly takes any time at all, and you shouldn't keep staggering along in a high pitch attitude after you've done so.  It increases risk for no good reason.

I've spoken with other Mooney drivers about our findings, and none of them have hard data to dispute the 73 MIAS number.  But some of them say they're just not willing to use that slow a speed and that high a deck angle right after liftoff, and it's difficult to argue with that advice.  Were I a DPE evaluating a candidate's short field takeoff performance in a Vintage Mooney, I'd have no quarrel with a candidate who told me 80 MIAS was their best tradeoff between performance and safety, even if a slower speed might achieve a slightly shorter obstacle distance.  One thing I try to drive home to my students about takeoff and landing performance numbers is that if tiny variations in speed or technique are actually the difference between going into the trees or not, you've already committed the cardinal sin of a judgement error.

Just my $0.02, interested to continue reading what others have to say.

[takair]

1 hour ago, Vance Harral said:

Is there confusion with Vx in our vintage M20s?  I say yes, absolutely.  Permit me to elaborate.

I don't own an E model, but I sometimes give training in them.  I have a copy of the 1966-67 M20E "Super 21" Owner's Manual dated March 1967 for S/Ns 832-1308 and 67001-67062.  I don't see "Vx" or a "Best Climb Angle" speed published anywhere in that manual.  If someone can post a screen shot from that manual or a later M20E edition showing a published Vx, please do so.  Best as I can tell, Mooney simply didn't publish one for the M20E, and that's what I teach.  But I want to know if I'm wrong.

In any case, I do own a 1976 M20F model, and the October 1975 revision of the M20F Owners Manual has a Climb Performance table which charts both "Best Angle" and "Best Rate" climb speeds.  It claims the Best Angle speed is 94 MIAS/82 KIAS at all altitudes, while showing Best Rate to vary from 113/98 at sea level to 96/83 at 16K pressure altitude.  But... that chart has a Conditions section which says those speeds are with gear and flaps up.  In contrast, the Takeoff Distance chart specifies wing flaps in the takeoff position, and the "Normal Procedures" says not to raise flaps until clear of obstacles.  It also says not to raise the gear until you can do so safely, which obviously means at least the first few feet of takeoff occur with the gear down.  Conclusion: the chart in the M20F Owners Manual which specs a Best Angle climb speed isn't actually applicable to takeoff and obstacle clearance!

As a CFI, this leaves me with a dilemma in teaching proper short-field technique in vintage Mooneys.  While I don't necessarily claim it's the "one true way", I teach short field takeoff technique in vintage Mooneys with flaps set to takeoff and gear down until 50' AGL; then we raise the gear, then the flaps.  Using takeoff flaps matches what the Owners Manual prescribes.  My rationale for leaving the gear down thoughout the 50' climb is, during the roughly 6 seconds it takes to do this while pitched for Vx in that configuration, I want the pilot fully focused on pitch control, and spring-loaded to shove the nose down if the engine takes a holiday (or even hiccups).  Neither of those things is well served by taking one's hand off the throttle and trying to raise the gear, especially in a Johnson bar Mooney.

So what speed should one use for this 50' climb with gear down and takeoff flaps?  The M20F Owners Manual doesn't say.  Even if I changed technique to raise the gear "instantly", I still don't have a published Vx with flaps set to takeoff, which is what the manual prescribes until the obstacle is cleared.  Therefore, one has to determine Vx experimentally.  My partners and I have run this experiment several times in our M20F, and we find Vx with takeoff flaps and gear down at our home airport (KLMO, elevation 5050), is about 73 MIAS.  Yes, 73 MPH indicated.  Yes, that's uncomfortably slow.  Not only is it uncomfortably slow, it also requires an uncomfortably high pitch attitude and deck angle.  It really does achieve the shortest distance over a 50' obstacle, but it's a vulnerable configuration, and none of us like it.  When we practice true short field technique, we expect our students (and ourselves) to immediately lower the nose to a Vy climb attitude as soon as the obstacle is cleared.

Note: many pilots I work with on short field takeoffs hold Vx far too long.  The mythical 50' obstacle isn't much higher than the top of a tall hangar, and since you're going to be climbing in the neighborhood of 500 fpm, it only takes 1/10th of a minute to get there.  That's about 6 seconds.  By all means, clear the obstacle, but it hardly takes any time at all, and you shouldn't keep staggering along in a high pitch attitude after you've done so.  It increases risk for no good reason.

I've spoken with other Mooney drivers about our findings, and none of them have hard data to dispute the 73 MIAS number.  But some of them say they're just not willing to use that slow a speed and that high a deck angle right after liftoff, and it's difficult to argue with that advice.  Were I a DPE evaluating a candidate's short field takeoff performance in a Vintage Mooney, I'd have no quarrel with a candidate who told me 80 MIAS was their best tradeoff between performance and safety, even if a slower speed might achieve a slightly shorter obstacle distance.  One thing I try to drive home to my students about takeoff and landing performance numbers is that if tiny variations in speed or technique are actually the difference between going into the trees or not, you've already committed the cardinal sin of a judgement error.

Just my $0.02, interested to continue reading what others have to say.

From my manual for my E it says 80.  Based on the previous checklist, one might assume it is flaps up.  However, I find it uncomfortable to be heading at an obstacle at 80mph and put the flaps up.  I find 80 with takeoff flaps seems to work well if one truly needs Vx climb.  I practice it on occasion, but don’t use it routinely….it is quite a steep angle.

[Ragsf15e]

My ‘68 F is 94mph for Vx but it specifies Gear and flaps up.  I’d prefer to keep TO flaps until obstacle clearance as well. but then the poh also says to set power to 26/2600 for normal climb and many people don’t do that.

[Nukemzzz]

2 hours ago, takair said:

From my manual for my E it says 80.  Based on the previous checklist, one might assume it is flaps up.  However, I find it uncomfortable to be heading at an obstacle at 80mph and put the flaps up.  I find 80 with takeoff flaps seems to work well if one truly needs Vx climb.  I practice it on occasion, but don’t use it routinely….it is quite a steep angle.

Your manual is what the original manual for my 66E says.  Note how it doesn't mention flap position adjacent the 80mph Vx speed. Attached you'll see the March 1967 revision of the 1966-1967 M20E Super 21 manual.  It says 94mph and mentions gear and flaps retracted in the same sentence.  My theory is this 80mph was with Takeoff flaps and maybe the test pilot(s) reported something to use that they later improved upon with further measurements and testing?.  It seems like Mooney changed their mind on this during the 67 model year.  I don't know why they wouldn't update the 65E as well.  

So what you are showing and what is in the March 67 manual is exactly what I'm looking at here with this post.

 

[Nukemzzz]

3 hours ago, Vance Harral said:

I have a copy of the 1966-67 M20E "Super 21" Owner's Manual dated March 1967 for S/Ns 832-1308 and 67001-67062.  I don't see "Vx" or a "Best Climb Angle" speed published anywhere in that manual. 

My copy of that exact same manual calls out "speed for maximum angle of climb" at the top of page 25.  Does yours not say that?  See my post above for the screenshot.

[Nukemzzz]

5 hours ago, Vance Harral said:

Is there confusion with Vx in our vintage M20s?  I say yes, absolutely.  Permit me to elaborate.

I don't own an E model, but I sometimes give training in them.  I have a copy of the 1966-67 M20E "Super 21" Owner's Manual dated March 1967 for S/Ns 832-1308 and 67001-67062.  I don't see "Vx" or a "Best Climb Angle" speed published anywhere in that manual.  If someone can post a screen shot from that manual or a later M20E edition showing a published Vx, please do so.  Best as I can tell, Mooney simply didn't publish one for the M20E, and that's what I teach.  But I want to know if I'm wrong.

In any case, I do own a 1976 M20F model, and the October 1975 revision of the M20F Owners Manual has a Climb Performance table which charts both "Best Angle" and "Best Rate" climb speeds.  It claims the Best Angle speed is 94 MIAS/82 KIAS at all altitudes, while showing Best Rate to vary from 113/98 at sea level to 96/83 at 16K pressure altitude.  But... that chart has a Conditions section which says those speeds are with gear and flaps up.  In contrast, the Takeoff Distance chart specifies wing flaps in the takeoff position, and the "Normal Procedures" says not to raise flaps until clear of obstacles.  It also says not to raise the gear until you can do so safely, which obviously means at least the first few feet of takeoff occur with the gear down.  Conclusion: the chart in the M20F Owners Manual which specs a Best Angle climb speed isn't actually applicable to takeoff and obstacle clearance!

As a CFI, this leaves me with a dilemma in teaching proper short-field technique in vintage Mooneys.  While I don't necessarily claim it's the "one true way", I teach short field takeoff technique in vintage Mooneys with flaps set to takeoff and gear down until 50' AGL; then we raise the gear, then the flaps.  Using takeoff flaps matches what the Owners Manual prescribes.  My rationale for leaving the gear down thoughout the 50' climb is, during the roughly 6 seconds it takes to do this while pitched for Vx in that configuration, I want the pilot fully focused on pitch control, and spring-loaded to shove the nose down if the engine takes a holiday (or even hiccups).  Neither of those things is well served by taking one's hand off the throttle and trying to raise the gear, especially in a Johnson bar Mooney.

So what speed should one use for this 50' climb with gear down and takeoff flaps?  The M20F Owners Manual doesn't say.  Even if I changed technique to raise the gear "instantly", I still don't have a published Vx with flaps set to takeoff, which is what the manual prescribes until the obstacle is cleared.  Therefore, one has to determine Vx experimentally.  My partners and I have run this experiment several times in our M20F, and we find Vx with takeoff flaps and gear down at our home airport (KLMO, elevation 5050), is about 73 MIAS.  Yes, 73 MPH indicated.  Yes, that's uncomfortably slow.  Not only is it uncomfortably slow, it also requires an uncomfortably high pitch attitude and deck angle.  It really does achieve the shortest distance over a 50' obstacle, but it's a vulnerable configuration, and none of us like it.  When we practice true short field technique, we expect our students (and ourselves) to immediately lower the nose to a Vy climb attitude as soon as the obstacle is cleared.

Note: many pilots I work with on short field takeoffs hold Vx far too long.  The mythical 50' obstacle isn't much higher than the top of a tall hangar, and since you're going to be climbing in the neighborhood of 500 fpm, it only takes 1/10th of a minute to get there.  That's about 6 seconds.  By all means, clear the obstacle, but it hardly takes any time at all, and you shouldn't keep staggering along in a high pitch attitude after you've done so.  It increases risk for no good reason.

I've spoken with other Mooney drivers about our findings, and none of them have hard data to dispute the 73 MIAS number.  But some of them say they're just not willing to use that slow a speed and that high a deck angle right after liftoff, and it's difficult to argue with that advice.  Were I a DPE evaluating a candidate's short field takeoff performance in a Vintage Mooney, I'd have no quarrel with a candidate who told me 80 MIAS was their best tradeoff between performance and safety, even if a slower speed might achieve a slightly shorter obstacle distance.  One thing I try to drive home to my students about takeoff and landing performance numbers is that if tiny variations in speed or technique are actually the difference between going into the trees or not, you've already committed the cardinal sin of a judgement error.

Just my $0.02, interested to continue reading what others have to say.

I think you've hit on it.  I think the 80mph (old number) was gear down and flaps at the takeoff setting, and in that config the best angle of climb is a stunt pilot attitude to the moon.  Maybe... 80mph is as high as you should go without being considered "aerobatic" (What is it?  20 degrees and you need a parachute?)?  Wouldn't a very steep attitude also put you at higher risk of a wind sheer related stall?  Lots of good reasons to not climb that aggressively...not the least of which is I have to lean way down and jerk quite a bit to get the J-Bar down.  Also, my arm isn't the longest so I can barely see outside for those few seconds.  In 67 maybe the FAA said that's too steep of a climb... but they didn't want the takeoff distance to suffer too much so they changed to an imaginary scenario of gear and flaps up before your passengers even notice you are off the ground because the numbers look better?  Could it be a marketing reason?

So now I'm wondering if the takeoff distance numbers changed from the 66 to the 67 manuals?  @takair what does your 65 manual have for takeoff distances?  I'll post the March 67 below for the same.  

[AerostarDriver]

I have a 71 E model; the manual says to retract the gear as soon as gear retraction airspeed has been achieved. I fly Vx only until I clear the 50 foot obstacles. The one thing I can't seem to figure out is how 80-84 makes since for the best angle. Some performance data in my airplane:

STD, 1000 foot field elevation, single pilot, full fuel

350-400 Ft/min @ 84 MPH indicate/72Kts Gnd(w/ Flaps):  Calculates out to 2.5 Degrees

1100 Ft/min @ 108 MPH indiciated/89Kts Gnd(w/o Flaps): Calculates out to 7 Degrees

Given that piece of information, I struggle to see the benefit of Vx given the extremely high deck angle and low stall margin.

[PT20J]

There is the practical test to ACS standards, and there is the best way to fly the airplane. They are not always in agreement. For a more in depth discussion, see https://www.advancedpilot.com/articles.php?action=article&articleid=1842 and also many excellent articles at https://www.nar-associates.com/technical-flying/technical_flying.html

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[takair]

8 hours ago, Nukemzzz said:

I think you've hit on it.  I think the 80mph (old number) was gear down and flaps at the takeoff setting, and in that config the best angle of climb is a stunt pilot attitude to the moon.  Maybe... 80mph is as high as you should go without being considered "aerobatic" (What is it?  20 degrees and you need a parachute?)?  Wouldn't a very steep attitude also put you at higher risk of a wind sheer related stall?  Lots of good reasons to not climb that aggressively...not the least of which is I have to lean way down and jerk quite a bit to get the J-Bar down.  Also, my arm isn't the longest so I can barely see outside for those few seconds.  In 67 maybe the FAA said that's too steep of a climb... but they didn't want the takeoff distance to suffer too much so they changed to an imaginary scenario of gear and flaps up before your passengers even notice you are off the ground because the numbers look better?  Could it be a marketing reason?

So now I'm wondering if the takeoff distance numbers changed from the 66 to the 67 manuals?  @takair what does your 65 manual have for takeoff distances?  I'll post the March 67 below for the same.  

No cool pictures in the 64, 65, 66 manual…..  words are similar.  I think we have put together a picture that the 80mph Vx is gear down flaps TO.  
 

To the OP, I think others have mentioned this, when taking the check ride, if/when the subject comes up, have the discussion with the examiner.  On a CFI check ride, this would be a “teaching moment”.  Consider discussing the lack of detail in the manual, experience with the manuever and the risks involved.  I think you will do fine given your interest in the topic…

 

 

[carusoam]

Summary-ish…

1) Our documents went from Stone Age, to somewhat modern in the time that M20Es were being manufactured….

2) We know the latest POH for the M20E has the most complete procedures and data for flying the M20E… independent of the year it was manufactured…

3) We know the owners manual for the exact year your M20E was manufactured is a legal important document to have in the plane…

4) We know that proper engine management didn’t catch up until after the M20E production had already ended…

5) The latest POH for the M20E is probably printed in 1976…

6) Being part of the certified world has its advantages… the later POHs were still connected to the earlier serial numbers of the same model…

7) Any STCs modify this conversation… if you have any STCs…

 

How you discuss this with your DPE is important…. I spoke with the guy that signed my aircraft’s AW page for this advice… 35 years after he signed it…   Bill Wheat was an amazing engineer at Mooney! I spoke with him by phone in y2k…. My plane didn’t have any manuals when I got it… calling the factory was an amazing experience…

PP thoughts only, not a CFI…

Best regards,

-a-

[Shiny moose]

even though the nice little picture in the manual shows the gear down over those trees, you really need the gear up to get your climb performance.

[carusoam]

1 hour ago, Shiny moose said:

even though the nice little picture in the manual shows the gear down over those trees, you really need the gear up to get your climb performance.

There is a requirement regarding how this works for ordinary real people…

Based on what happens when crammed for time and space…

Having the gear up makes a lot of sense…

But, getting it up causes a momentary distraction, and sometimes less than optimal attitude control, while climbing at Vx…

 

So… if the latest procedure says gear down, and flaps T/O… until clear of the obstacle… expect the logic is following human performance characteristics…

Even with electric gear, the timing of getting the gear up and clean…. The 50’ tall tree is already in the rear view mirror…

 

Using the numbers in the POH requires following the procedures that go with them…

 

Fortunately, today… we can prove how good our machines and our modified procedures are with WAAS data and CloudAhoy…. But, using that… is probably not part of this thread… 
 

PP thoughts only, not a CFI…

-a-

[Browncbr1]

The reason why it is taught to leave gear down until clear of the obstacle is because some planes have gear doors that open up and create drag in order to stow the gear before closing back up.     I don’t know of any complex singles that have that kind of gear door… it’s just larger jets I know of like that.   In any case, the DPE’s I’ve talked to say that is the FAA thinks that is the right way to teach due to learning primacy.  They also acknowledge that not all planes can get the best performance like that.   I teach that gear comes up when no more usable runway or clear obstacle.   In my personal plane with manual gear, it comes up as soon as possible, because I can put it back down in about 1 second and I want to be clean.  I leave flaps at TO until Vy.   With electric gear, it is wait to use up runway.  

Edited February 21, 2022 by Browncbr1

[Vance Harral]

12 hours ago, Nukemzzz said:

My copy of that exact same manual calls out "speed for maximum angle of climb" at the top of page 25.  Does yours not say that?  See my post above for the screenshot.

I stand corrected, my copy of the manual does have that sentence.  I just missed it, buried as it is at the very tail end of the verbiage, and with no corresponding graph or table.  Thanks for the correction.

As others have noted, the manual doesn't actually state the gear/flaps configuration at which 80 MIAS achieves best angle.  People are speculating above that it's with gear down and flaps in the takeoff position.  But the manual doesn't actually say that, and that number seems to be at odds with my experiments in our F model.  The E and F are not exactly the same, though, despite being pretty similar.

I stand by my position that leaving the gear down while topping a 50-ish foot obstacle is the most practical tradeoff for obstacle clearance.  Again, if raising the gear during that 6 or so seconds is really the difference between clearing the trees or not, you shouldn't have taken off in the first place.

[Blue on Top]

Thanks for the call in @PT20J  All y'all are making this way too complicated.  All the information above is great, but ...

Vy is best RATE of climb speed, maximum EXCESS (horse)power and minimum sink speed when the fan quits cooling.  This speed is NOT FAA approved.

Vx is best angle of climb speed and IS FAA approved.  It is the best speed to clear an obstacle at the end of the runway.  The Owner's Manual/Pilot Operating Handbook/Airplane Flight Manual/etc. provides data for the shortest takeoff possible over a 50' obstacle.  The manual will state takeoff performance when when the airplane is configured for takeoff, the brakes are held until full power is achieved, the airplane is accelerated to Vr, rotated and pitched to Vx until 50'.  The data ends at this point.

Bonus Data: Yes, Vx is a very nose-high attitude.  IF the engine quits, pitch down to minimum sink (Vy, Vbg).  As mentioned above, add safety margin.

PS. Yes, All of you should be able to meet (or exceed) book performance.

PS2.  If I'm not too late, this would make a good "The Mooney Flyer" article.

[PT20J]

There is another reason for raising the gear at as low an airspeed as possible in a Mooney. The force required to raise the gear increases greatly with airspeed. This is really apparent with the manual gear. I puts greater strain on the electric drive system to raise the electric gear at higher airspeeds. Also, I understand that the lower gear doors require additional force to raise the gear on later airplanes. Be safe, but be kind to your gear retraction system.

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