Learning to Land your Mooney

[gsxrpilot]

Good pilots don't use absolutes such as, only, always or never.

[donkaye]

31 minutes ago, teejayevans said:

Airspeed is always secondary in real flying (power off stalls don't count because you only do these in practice, I hope). Even landings where it's important to control speed, it's more important to control altitude.

Even if you're transitioning to restrictive airspace that has a speed limit, it's not something that you can't anticipate and requires a quick response.

I guess that we will have to agree to disagree on that one.

[Hank]

3 hours ago, gsxrpilot said:

Good pilots don't use absolutes such as, only, always or never.

You're right, there are absolutely no absolutes! That's why I even make occasional landings at or near Flaps Full Down. More so than with Flaps Up.  

[Bob - S50]

10 hours ago, donkaye said:

Also, with all due respect:

Questions:

1. Suppose your flight instructor asked you to precisely maintain a climb rate of 500 ft/min (not 1 foot off) and an airspeed secondarily of 90 knots.  What would you use to control the rate precisely?

2.  Suppose your flight instructor asked to to maintain an airspeed of exactly 59 knots (not 1 foot off) and exactly 5,000 feet altitude.  What would control the airspeed primarily?

1.  It can be done either way.  That was my point.  Personally, since I assume you are setting up a situation that did not require full power, if my rate of climb was off I would use pitch to make a correction.  If my speed was off I would use the throttle to make a correction.  I also know that if I make a change in pitch or power, it is going to require an adjustment in the other.  So when I make the required adjustment I will instinctively make an adjustment to the other in anticipation of a need of that adjustment.

As you said in the opposite case of a 500 fpm descent (ILS/LPV), pitch is primary to maintain the glideslope, power is used to maintain airspeed.

2.  Since I am not at stall speed (which I never should be), I would still use power to control speed and pitch to maintain altitude knowing that a change in one will require a change in the other.

Let me pose a situation to you.

You are in the flare for a landing (actually flying not preparing to fly by pumping the yoke on the ground) and you 3 feet too high.  What do you use to control your altitude?  Pitch or power?

There is NO one right answer.

Thrust is aligned with the fuselage so I use it to control in that dimension (speed).  Lift is perpendicular to the fuselage so I use pitch to control in that direction (altitude).  The exception again being max or no power situations.  Like I said, it has worked for me so far (as taught to me by the USAF).

Many others, including one of my partners chooses to use pitch for speed control and power for altitude control in the pattern.  That's his (and everybody else's) choice.

Because he only seems to correct one thing at time, when he pulls the nose up to slow from base turn speed to final approach speed we get REALLY high.  Once on speed he pulls the power back to descend.  This results in either a very steep final with, high sink rate, low airspeed, and low power.  Makes me worry about stalling in the flare every time.  Or a normal descent and a long landing.  That's better except on short runways.  If he does it again next time I fly with him I've decided to say something to him.  If he keeps doing that I'm going to quit flying with him.

To each his own.

Bob

[donkaye]

53 minutes ago, Bob - S50 said:

Because he only seems to correct one thing at time, when he pulls the nose up to slow from base turn speed to final approach speed we get REALLY high.  Once on speed he pulls the power back to descend.  This results in either a very steep final with, high sink rate, low airspeed, and low power.  Makes me worry about stalling in the flare every time.  Or a normal descent and a long landing.  That's better except on short runways.  If he does it again next time I fly with him I've decided to say something to him.  If he keeps doing that I'm going to quit flying with him.

To each his own.

Bob

This isn't good.  On landing BOTH airspeed and slope are important factors.  In simple landings (not following a 737 in) I like to keep things simple.  On downwind the airplane should be configured with gear and approach flaps.  At the 3° slope point with the aim point, power should be reduced to a setting that will allow a rate of descent that will keep you on slope, base turn should be begun, and full flaps applied.  The nose will want to go down, but it should be held at the 3° slope position.  The drag of the flaps will then slow the plane to the base approach speed while the plane remains on slope.  Trim the airplane.  When on final, reduce power slightly and smoothly pitch to the correct final approach speed based on landing weight.  Power is then used to manage the rate of descent down to the flare point where power is fully withdrawn and the roundout begun.  The rate of flare should be such that the main wheels roll onto the runway without so much as a chirp.

[carusoam]

I think I'm getting a sense for how different people attack this question...

1) people new to aviation trying to get a hold of the ideas of airspeed and altitude control early in their flying career.  (Lots of simplified methods that work over a narrow-ish range)

2) people that have mastered the plane they always fly.  (Lots of experience and memorized/accumulated methods)

3) people that have been trained in energy management.  (Physics and engineering)

4) people that have been trained in energy management specific to aviation. (Military trained and pro pilots)

5) people that have learned and shared energy management techniques specific to Mooneys.

 

Observation regarding energy management...

A) The energy accumulated in an airframe is both kinetic (speed) and potential (altitude).  Both types of energy can be converted from one to the other.  Energy losses occur through dissipation. Friction converts all this energy to heat...

B ) Landing a plane requires dissipating the excess energy.  Some base level energy is required to keep flying and avoid a stall,  a small amount is required for the landing flair.

C) Dissapating energy is complex to get right. We don't have an energy meter.  Foreflight is getting close with the glide range rings.  AOA is a nice way to measure minimum kinetic energy (with respect to airspeed)

D) Slowing down, while going down is one of the more challenging things to accomplish in a Mooney.

 

All of this leads to the next thing...  The energy balance equation.  A mathematical description of total energy in - total energy out covering all the details of where it comes from to where it goes...

It starts with pushing the big black knob in, converting chemical potential energy (pounds of fuel) into kinetic energy (mass moving at speed) then converting further into potential energy (mass at altitude).

Dissipating this boatload of energy in a controlled fashion is required to have that gentle landing on the mains.

 

Mooney methods of dissipating energy...

1) increase AOA. Moving the lift vector back...

2) slip. Increasing frontal surface area presented to the wind...

3) Lower the landing gear.  Purist form of drag addition...

4) deploy speed brakes.  Loses lift that gets balanced by an increased AOA.  Increased AOA moves the lift vector back...

 

PP ideas for discussion, I am not a physisist.  I got some ideas from reading Nate Jaros' book and was motivated by Bob -S50's post above.  

The other day I had excess speed on final, raised the nose to slow down.  The excess energy became visibly obvious as my altitude was far from ideal. Chopping the throttle to get back onto Nate's glide wire ran up a 1000+fpm descent rate.  So much for a stable approach....

 

The energy balance equation can be pretty complex mathematically.  Yet Flying can be executed pretty well by highschool aged kids...

Final thought...  Increasing the mass of the plane, speed of the plane, and power of the engine makes things a bit more complex one step at a time.

If you read this far, you really get it!!!  

Best regards,

-a-

 

[gsengle]

Totally in camp three here. But I believe every pilot should understand the power curve both intuitively and explicitly. You will end up on the back side of the power curve before you land, the question is when.

I prefer to stay on the front side or the bottom until just over the fence, so using pitch (have some extra energy to spare before getting on the back side or stalling) gives me altitude if I need it quickly, or in the case of engine trouble.

But it *is* amazing how steeply you can approach with power on, on the back side of the power curve, if you need to. But in that regime any power loss requires lowering the nose immediately.

If you understand the power curve you can always feel what is going on and know when and where power or pitch are what you need. Sure good to be consistent with landings and associated speeds, but even more important to be able to feel why those speeds work and how to deal with other speeds, being too high, approaching over obstacles, etc

As others have implied, flying is too complex to be reduced to a recipe.... The recipe is just the ideal.

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[ArtVandelay]

Good pilots don't use absolutes such as, only, always or never.

I disagree....

I only change fuel tanks when above an airport or suitable road for a landing.

I always do a preflight and take a fuel sample.

I never fly through thunderstorms.

[ArtVandelay]

31 minutes ago, teejayevans said: Airspeed is always secondary in real flying (power off stalls don't count because you only do these in practice, I hope). Even landings where it's important to control speed, it's more important to control altitude.

Even if you're transitioning to restrictive airspace that has a speed limit, it's not something that you can't anticipate and requires a quick response.

I guess that we will have to agree to disagree on that one.

Ok, tell me where airspeed is primary during normal flying ops.

[gsxrpilot]

Just now, teejayevans said:

I disagree....

I only change fuel tanks when above an airport or suitable road for a landing.

I always do a preflight and take a fuel sample.

I never fly through thunderstorms.

Good for you, but I'm standing by my original statement.

[carusoam]

Airspeed is the primary reason for me to buy a Mooney...  Speed, efficiency, safety, and wicked cool good looks!

It has always been that way...  (Someday it may change...)

Best regards,

-a-

[donkaye]

20 minutes ago, teejayevans said:

Ok, tell me where airspeed is primary during normal flying ops.

Not to be flip about it, but airspeed is most important when you want it to be important.  For me it's most important during the landing phase of flight when we are behind the power curve. It would be important for constant airspeed climbs and descents.   It is also be important as relates to Vne.  In turbulence it is important only to the extent of being less than Va.  For our airplanes, airspeed limits in Class C and B airspace really don't apply, since we can't get to those speeds.  Airspeed really isn't important in level flight, as ATC cares more about our altitude than airspeed.

[ArtVandelay]

Good for you, but I'm standing by my original statement.

But you don't see you made an absolute statement about not using absolute statements?

[Hank]

Deja vu all over again . . .

"There are absolutely no absolutes!"

To which I politely reply, "Balderdash!" What goes up must come down. We've had a perfect record for over 100 years--we haven't left one up there yet. 

When landing, in the pattern and on approach, it's pitch for airspeed, power for altitude. If im low, maintain pitch and add a smidgen of throttle. 

[PTK]

1 hour ago, teejayevans said:

Ok, tell me where airspeed is primary during normal flying ops.

Well, considering the title of this thread is about landing, in a stabilized descent (constant speed) airspeed is primary. 

[donkaye]

9 minutes ago, Hank said:

When landing, in the pattern and on approach, it's pitch for airspeed, power for altitude. If im low, maintain pitch and add a smidgen of throttle. 

If low AND slow, counter-intuitive as it might seem, the thought process and actions should be: Lower the nose to increase speed while simultaneously adding power to increase altitude.

[ArtVandelay]

1 hour ago, teejayevans said: Ok, tell me where airspeed is primary during normal flying ops.

Well, considering the title of this thread is about landing, in a stabilized descent (constant speed) airspeed is primary. 

I would argue that stabilize descent is primary, then adjusting speed is secondary.

[donkaye]

21 minutes ago, teejayevans said:

I would argue that stabilize descent is primary, then adjusting speed is secondary.

If I'm coming into San Jose in IMC conditions and there is a string of airliners lined up and I want to get in in some reasonable time frame, I let the controller know that I can maintain 160 knots on final and they will usually fit me in with the comment to maintain best forward speed until 5 miles from the airport.  I know from experience that I can slow from 160 knots to 75 knots within that distance.  In this situation I will pitch for slope and power for airspeed, since slope is most important on the ILS and as long as I can maintain in excess of 160 knots speed is secondary.  At 5 miles the speed brakes get popped, the speed slows to 140 knots and the gear gets dropped all the while trimming (pitch) to maintain the slope with the variable airspeed decreasing.  At 110 knots all the flaps are deployed, slope is maintained with pitch until the speed slows to 75 knots.  At 75 knots that constant speed transitions to being maintained with elevator and power transitions to control rate of descent until the flare at the 1,000 foot marker.  This transition of thought process becomes automatic with experience and I don't give it a second thought so to speak.

The above is what I mean when I say pitch controls whatever is most important in any phase of flight with power controlling the other.  This was drilled into me by my mentor instructor and aeronautical engineer, Robert Goldin.

I have taught this for the past 22 years and I haven't had a student disagree with the process by the time we were finished with their training.  Of course by that time all of their landings were perfect.  ;-)

 

[ArtVandelay]

You slow down to 75 knots while still in IMC? I always like a little extra speed (90 knots) to leave margin of error for wind shear and I feel more stabilize if it's bumpy, once I have runway in sight I deploy full flaps and slow down.

[donkaye]

1 minute ago, teejayevans said:

You slow down to 75 knots while still in IMC? I always like a little extra speed (90 knots) to leave margin of error for wind shear and I feel more stabilize if it's bumpy, once I have runway in sight I deploy full flaps and slow down.

Definitely not.  I assumed I had broken out earlier.  Most times you will know even before you run the approach what the ceiling is.

[M20S Driver]

11 hours ago, gsengle said:

I prefer to stay on the front side or the bottom until just over the fence, so using pitch (have some extra energy to spare before getting on the back side or stalling) gives me altitude if I need it quickly, or in the case of engine trouble.

But it *is* amazing how steeply you can approach with power on, on the back side of the power curve, if you need to. But in that regime any power loss requires lowering the nose immediately.

If you understand the power curve you can always feel what is going on and know when and where power or pitch are what you need. Sure good to be consistent with landings and associated speeds, but even more important to be able to feel why those speeds work and how to deal with other speeds, being too high, approaching over obstacles, etc

As others have implied, flying is too complex to be reduced to a recipe.... The recipe is just the ideal.

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"I prefer to stay on the front side or the bottom until just over the fence"

what is the bottom of the power curve speed at gross weight in your Ovation?  

I have been using Don Kaye's video and hand out and use the numbers per his sheets and it works perfectly every time.  I always assumed that the bottom of the power curve is close to short field approach speed (70 kts at gross with power).  Is that correct?

[gsengle]

Bottom of the curve is best glide... Means I keep up around 85+ on final until close to the runway in the O

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[M20S Driver]

12 minutes ago, gsengle said:

 

Bottom of the curve is best glide... Means I keep up around 85+ on final until close to the runway in the O

 

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I thought 85 was best glide with flaps and gear up.  I was expecting a lower number in landing configuration (70 to 75?).

[gsengle]

Closer to 90 at gross, don't think gear matters as much, and flaps help maybe 5kts? Just a guess. Point is I don't like to get slow too early, unless it's a short field/obstruction...

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[Bob - S50]

18 hours ago, donkaye said:

If low AND slow, counter-intuitive as it might seem, the thought process and actions should be: Lower the nose to increase speed while simultaneously adding power to increase altitude.

 

Or, add power to accelerate and simultaneously lower the nose to keep from climbing.  Potato, Pattaato.