Adding Flaps in a Chandelle

dell30rb

dell30rb

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Sunday I was out flying around, and decided to try my hand at the chandelle. It occurred to me that it would be a good idea to add 10 degrees of flaps when you are nearing Vx (in a sessna) to give yourself a little bit of extra climbing power. Does anyone do this or would it be considered negligible?
 
dell30rb said:
Sunday I was out flying around, and decided to try my hand at the chandelle. It occurred to me that it would be a good idea to add 10 degrees of flaps when you are nearing Vx (in a sessna) to give yourself a little bit of extra climbing power. Does anyone do this or would it be considered negligible?
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The Airplane Flying Handbook doesn't call for it, so I wouldn't do it on a checkride without good justification. Per the AFH, you start with flaps up, and then it doesn't mention them again. (BTW, were you providing captions on Alaska Wing Men? "sessna"?) :)
 
gprellwitz said:
The Airplane Flying Handbook doesn't call for it, so I wouldn't do it on a checkride without good justification. Per the AFH, you start with flaps up, and then it doesn't mention them again. (BTW, were you providing captions on Alaska Wing Men? "sessna"?) :)
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That's how its spelled. It was spelled that way on TV so it can't be wrong. :hairraise:

I noticed it was not in the AFH however it does seem like the best way to perform the maneuver. I agree with not doing it in a checkride w/o justification. Kinda like not answering a question you aren't asked!
 
Vx is best angle of climb.

In a chandelle you're supposed to be gaining altitude during the 180 turn.

How would applying flaps assist in gaining altitude?
 
dmccormack said:
Vx is best angle of climb.

In a chandelle you're supposed to be gaining altitude during the 180 turn.

How would applying flaps assist in gaining altitude?
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When you are below Vy and you near Vx the airplane climbs faster with 10 degrees of flaps. That's why an obstacle clearance takeoff is supposed to be done at Vx with 10 degrees of flaps (per the POH for the sessna in question)

You might have misunderstood my original post... in what I described I would leave the flaps retracted until near the end of the maneuver, and I would only deploy them after slowing through Vy and nearing Vx
 
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Yes it is definitely best angle, and it is also the best with respect to time. Vx and climb flaps will give you a higher FPM than Vy. Plus the airplane will have a slightly slower stall speed so you'll be able to continue the climb for just a little bit longer.

Negligible I know but it might give you that extra 15 feet to clear that pine tree on the other side of the canyon, or that extra altitude you need to defeat your opponent in a dogfight (hehe)
 
dell30rb said:
When you are below Vy and you near Vx the airplane climbs faster with 10 degrees of flaps. That's why an obstacle clearance takeoff is supposed to be done at Vx with 10 degrees of flaps (per the POH for the sessna in question)
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Actually, it doesn't "climb faster" with flaps applied.

Consider:

Flaps increase the camber of the wing. This increase both parasite and induced drag.

Drag reduces the total surplus power available for climbing (and only excess power results in a climb).

Flaps make the angle steeper, but it takes longer (time) to get to the same altitude.
 
dmccormack said:
Actually, it doesn't "climb faster" with flaps applied.

Consider:

Flaps increase the camber of the wing. This increase both parasite and induced drag.

Drag reduces the total surplus power available for climbing (and only excess power results in a climb).

Flaps make the angle steeper, but it takes longer (time) to get to the same altitude.
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I disagree, I think that the airplane will have a higher FPM at Vx than Vy, and FPM is a time based measurement.

They do increase drag but remember they also increase lift. There is a point where drag added surpasses lift added and they will retard your climbing ability, but that happens at higher flap settings and or airspeed than 10 degrees and Vx.
 
dell30rb said:
I disagree, I think that the airplane will have a higher FPM at Vx than Vy, and FPM is a time based measurement.

They do increase drag but remember they also increase lift. There is a point where drag added surpasses lift added and they will retard your climbing ability, but that happens at higher flap settings and or airspeed than 10 degrees and Vx.
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Please review the definition of your terms:

Vy = Best RATE of climb (time)
Vx = Best ANGLE of climb (altitude over distance)

See: http://www.faa.gov/library/manuals/aviation/pilot_handbook/media/PHAK - Chapter 10.pdf
 
dell30rb said:
I disagree, I think that the airplane will have a higher FPM at Vx than Vy, and FPM is a time based measurement.

They do increase drag but remember they also increase lift. There is a point where drag added surpasses lift added and they will retard your climbing ability, but that happens at higher flap settings and or airspeed than 10 degrees and Vx.
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No.

The ONLY time flaps add more lift than drag is below Vx. If you look at your airspeed dial that area will be WHITE ONLY.

Once you are in any portion of the green all light aircraft climb better with no flaps.
 
kgruber said:
No.

The ONLY time flaps add more lift than drag is below Vx. If you look at your airspeed dial that area will be WHITE ONLY.

Once you are in any portion of the green all light aircraft climb better with no flaps.
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Then why would obstacle clearance be done AT Vx with flaps? They wouldn't recommend them if they impeded your climb.
 
dell30rb said:
Then why would obstacle clearance be done AT Vx with flaps? They wouldn't recommend them if they impeded your climb.
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On a SHORT runway, with obstacles, some airplanes are configured with climb flap settings only because there is not enough distance to accelerate to Vx. The speed which you climb with flaps is NOT Vx.

You might call it Vxfe............but the airplane will climb better with a clean wing.

It is a compromise.
 
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dmccormack said:
Please review the definition of your terms:

Vy = Best RATE of climb (time)
Vx = Best ANGLE of climb (altitude over distance)

See: http://www.faa.gov/library/manuals/aviation/pilot_handbook/media/PHAK - Chapter 10.pdf
Click to expand...



The question I am asking..

Does an airplane have a higher FPM at:
Vx with flaps deployed
Vy with flaps retracted

^ I'm not 100 percent sure of the answer to this.

Kgruber, I was not suggesting deploying 10 deg flaps above Vx, I was suggesting deploying them as you approach Vx, because the airplane will climb better with them deployed from Vx on down to stall speed.
 
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If adding flaps increases power, think of the avgas we can save!!

The only time you are going to perform a chandelle in the real world (aerobatics not included), is on a commercial or flight instructor checkride. Don't do anything that is not in the Airplane Flying Handbook if you plan to pass the checkride.

Also, note that the 10 degrees of flaps does not apply to all airplanes.

Bob Gardner
 
bobmrg said:
If adding flaps increases power, think of the avgas we can save!!

The only time you are going to perform a chandelle in the real world (aerobatics not included), is on a commercial or flight instructor checkride. Don't do anything that is not in the Airplane Flying Handbook if you plan to pass the checkride.

Also, note that the 10 degrees of flaps does not apply to all airplanes.

Bob Gardner
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I understand this is a purely theoretical discussion and not likely to apply to anyone, ever. :)

On that note, I am not sure if the airplane will have a better FPM at Vx or Vy, so I'll concede that.

What I am really asking - and the original point of this post is that the chandelle is a maneuver which is designed to incorporate a 180 while trading all of your airspeed for altitude. You finish the maneuver with the stall horn squeaking.

It appears to me that I could get a few extra feet out of the cessna if I deployed 10 degrees of flaps when passing through Vx, on my way down to stall speed because A; the airplane will climb better with 10 deg of flaps at that point, and B the stall speed will be a tad lower, so I can stretch the climb out just a smidge longer.

^ Do you guys agree or disagree with that?
 
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bobmrg said:
If adding flaps increases power, think of the avgas we can save!!

The only time you are going to perform a chandelle in the real world (aerobatics not included), is on a commercial or flight instructor checkride. Don't do anything that is not in the Airplane Flying Handbook if you plan to pass the checkride.

Also, note that the 10 degrees of flaps does not apply to all airplanes.

Bob Gardner
Click to expand...
I don't think he is asking about the checkride, although I could be wrong. Looks to be only a discussion of theory. So one can try it if they like (even if its not in the AFH). If you would like to try it, at the end of the procedure watch altitude gained with and without your theory. Tell us how it goes.:thumbsup:
 
dell30rb said:
The speed at which you climb with flaps IS Vx. At least in the Cessna 152 I have been flying.
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No. Here is the direct quote from the 152 POH.

"""On a short field, 10° wing flaps and an obstacle clearance speed of 54 KIAS should be used. This speed provides the best overall climb speed to clear obstacles when taking into account turbulence often found near ground level."""

Nowhere did they mention 54 KIAS was Vx. Note it is a compromise due to the limited length of runway to accelerate and to turbulence considerations.

Note further on pg 4-15: """"If an obstruction dictates the use of a steep climb angle, the best angle-of-climb speed should be used with flaps up and maximum power."""""

Note on pg 4-3: Best Angle of Climb, Sea level through 10,000 Feet.....55 KIAS
 
dell30rb said:
The question I am asking..

Does an airplane have a higher FPM at:
Vx with flaps deployed
Vy with flaps retracted

^ I'm not 100 percent sure of the answer to this.
Click to expand...

I'm 100% positive of this:

Any airplane (even in a C152) will achieve the greatest altitude in the shortest amount of time with the least amount of drag and the greatest amount of excess power.

Flaps add drag (both induced and parasite).

I think you're confusing the use of flaps for short field takeoffs (which not all airplanes use, by the way).

The reason you use flaps is to increase the angle, not the rate.

So FPM will be greater clean.
 
dmccormack said:
I'm 100% positive of this:

Any airplane (even in a C152) will achieve the greatest altitude in the shortest amount of time with the least amount of drag and the greatest amount of excess power.

Flaps add drag (both induced and parasite).

I think you're confusing the use of flaps for short field takeoffs (which not all airplanes use, by the way).

The reason you use flaps is to increase the angle, not the rate.

So FPM will be greater clean.
Click to expand...

So will feet per distance be greater clean. Unless your short runway does not give you the option to accelerate to Vx.
 
kgruber said:
No. Here is the direct quote from the 152 POH.

"""On a short field, 10° wing flaps and an obstacle clearance speed of 54 KIAS should be used. This speed provides the best overall climb speed to clear obstacles when taking into account turbulence often found near ground level."""

Nowhere did they mention 54 KIAS was Vx. Note it is a compromise due to the limited length of runway to accelerate and to turbulence considerations.

Note further on pg 4-15: """"If an obstruction dictates the use of a steep climb angle, the best angle-of-climb speed should be used with flaps up and maximum power."""""

Note on pg 4-3: Best Angle of Climb, Sea level through 10,000 Feet.....55 KIAS
Click to expand...


I have to give that one to ya! I am used to seeing flaps down with Vx used as obstacle clearance and figured obstacle clearance was the same as best angle of climb.
 
I had an examiner yell at me on my Commercial checkride because I didn't put the gear down during a Chandelle. I racked my brain trying to think if I had ever been shown one like this before, and thought back to both the PTS and AFH, and neither technique was taught like this. After the ride, he mentioned to my CFI at the time he should start teaching a Chandelle with the gear down if you are in a complex A/C. My instructor and I just shook our heads. I teach from the AFH, and not what an DE thinks.
 
Flyparrothead said:
I had an examiner yell at me on my Commercial checkride because I didn't put the gear down during a Chandelle. I racked my brain trying to think if I had ever been shown one like this before, and thought back to both the PTS and AFH, and neither technique was taught like this. After the ride, he mentioned to my CFI at the time he should start teaching a Chandelle with the gear down if you are in a complex A/C. My instructor and I just shook our heads. I teach from the AFH, and not what an DE thinks.
Click to expand...

Wow. SMH
 
dell30rb said:
I have to give that one to ya! I am used to seeing flaps down with Vx used as obstacle clearance and figured obstacle clearance was the same as best angle of climb.
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Don't feel bad.

Instructors have been spewing out "flaps give more lift than drag" for as long as I remember..........which is getting to be a long time. It probably originated from WWII instructors, where there probably were aircraft that climbed better with some flap.

In the light aircraft we fly it is not an OWT, it is complete fallacy.

UNLESS: they are referring to (on a 152) the area between the bottom of the white to the bottom of the green........i.e.: 35 KIAS to 40 KIAS

Using flaps to climb in the vast majority of light aircraft is like using your parking brake in a drag race.
 
1st I agree don't use flaps on a check ride. It is a precision maneuver and if it isn't required then don't make it more complicated than it is.

However if you goal is to gain maximum altitude in the Maneuver there is a reason why you might use flaps. Flaps will let you fly slower and convert more of you kinetic energy into potential energy.

FWIW: my glider climbs much better with about 10 degrees of flaps.

Brian
CFIIG/ASEL
 
kgruber said:
Don't feel bad.

Instructors have been spewing out "flaps give more lift than drag" for as long as I remember..........which is getting to be a long time. It probably originated from WWII instructors, where there probably were aircraft that climbed better with some flap.

In the light aircraft we fly it is not an OWT, it is complete fallacy.

UNLESS: they are referring to (on a 152) the area between the bottom of the white to the bottom of the green........i.e.: 35 KIAS to 40 KIAS

Using flaps to climb in the vast majority of light aircraft is like using your parking brake in a drag race.
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I read something - somewhere that went like:
10 degrees = some lift, a little drag
20 degrees more lift, more drag
30 degrees= more lift, more drag
40 degrees= a little more lift, a lot more drag

I think that is a pretty accurate

I still think that some flaps near the very end of the maneuver might help because they will lower your stall speed. I'll give it a try sometime. Of course, as I said in my first reply to this message, no I have no plans of trying this on a checkride, and I am well aware of the reasons why this would be a bad idea.
 
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dell30rb said:
I understand this is a purely theoretical discussion and not likely to apply to anyone, ever. :)

On that note, I am not sure if the airplane will have a better FPM at Vx or Vy, so I'll concede that.

What I am really asking - and the original point of this post is that the chandelle is a maneuver which is designed to incorporate a 180 while trading all of your airspeed for altitude. You finish the maneuver with the stall horn squeaking.

It appears to me that I could get a few extra feet out of the cessna if I deployed 10 degrees of flaps when passing through Vx, on my way down to stall speed because A; the airplane will climb better with 10 deg of flaps at that point, and B the stall speed will be a tad lower, so I can stretch the climb out just a smidge longer.

^ Do you guys agree or disagree with that?
Click to expand...

Disagree.

Bob Gardner
 
dell30rb said:
I still think that some flaps near the very end of the maneuver might help because they will lower your stall speed. I'll give it a try sometime. Of course, as I said in my first reply to this message, no I have no plans of trying this on a checkride, and I am well aware of the reasons why this would be a bad idea.
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Why on earth do you think changing the configuration of the aircraft in the middle of the maneuver is a good idea?

Do you really want to be messing with the trim and/or applying extra pressure on the controls when you are approaching stall speed???

Last I checked there was no award for how high you can get in a chandelle. Seems like a case of extra effort to make the maneuver more difficult.
 
Fearless Tower said:
Why on earth do you think changing the configuration of the aircraft in the middle of the maneuver is a good idea?

Do you really want to be messing with the trim and/or applying extra pressure on the controls when you are approaching stall speed???

Last I checked there was no award for how high you can get in a chandelle. Seems like a case of extra effort to make the maneuver more difficult.
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Like I said, several times, I have no plans of trying this on a checkride. Why can't anyone get that in their head.

I don't see why adding flaps when I am approaching stall speed is going to cause any harm. Its not complicated. You just add the flaps in. You don't have to re trim, just release some back pressure.

And the whole point of the chandelle is to exchange every bit of available airspeed for altitude, while performing a quick 180 degree turn. Useful if you suddenly find yourself stuck in a canyon. It was not created by the FAA so that it could be included in the PTS.
 
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dell30rb said:
Like I said, several times, I have no plans of trying this on a checkride. Why can't anyone get that in their head.

I don't see why adding flaps when I am approaching stall speed is going to cause any harm. Its not complicated. You just add the flaps in. You don't have to re trim, just release some back pressure.

And the whole point of the chandelle is to exchange every bit of available airspeed for altitude, while performing a quick 180 degree turn. Useful if you suddenly find yourself stuck in a canyon. It was not created by the FAA so that it could be included in the PTS.
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You remain confused.

You think flaps = lift. <--period

This is incorrect.

The airplane only climbs because it has excess power (more than it needs to remain level).

Drag opposes thrust.

So guess what flaps do? (hint: add drag)
 
dmccormack said:
You remain confused.

You think flaps = lift. <--period

So guess what flaps do? (hint: add drag)
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Not so, please see my previous post.


dell30rb said:
I read something - somewhere that went like:
10 degrees = some lift, a little drag
20 degrees more lift, more drag
30 degrees= more lift, more drag
40 degrees= a little more lift, a lot more drag
Click to expand...



I know they add both lift and drag.

What happens when you suddenly apply flaps on approach? The airplane balloons up and slows down. That's extra lift and extra drag being added.

I know that the drag will inhibit your climbing performance in a constant airspeed climb, I see the flaps may potentially stretch the maneuver at the end to gain a little extra altitude. At any rate I'll try it this weekend and see what happens :)
 
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dell30rb said:
Not so, please see my previous post.


I know they add both lift and drag.

What happens when you suddenly apply flaps on approach? The airplane balloons up and slows down. That's extra lift and extra drag being added.

I know that the drag will inhibit your climbing performance in a constant airspeed climb, I see the flaps may potentially stretch the maneuver at the end to gain a little extra altitude. At any rate I'll try it this weekend and see what happens :)
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Guess what? More lift = more drag, as drag is a product of lift.

That momentary ballooning is:

  1. a "feature" of certain airplanes (such as Cessna 172s)
  2. evidence of poor aircraft control
  3. a result in a shift in the center of pressure, not a sudden abundance of lift.
 
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dmccormack said:
Guess what? More lift = more drag, as drag is a product of lift.



  1. a result in a shift in the center of pressure, not a sudden abundance of lift.
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I know that drag is a by-product of lift, in the case of flaps. I was merely pointing out that your previous statement that I think flaps add only lift, period, was wrong.
 
kgruber said:
No. The best way to do a 180 in a canyon is a "canyon" turn. Not a chandelle.

Learn about them HERE:
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Can you explain a canyon turn? I don't see anything there... and I won't be taking the course anytime soon.
 
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kgruber said:
Using flaps to climb in the vast majority of light aircraft is like using your parking brake in a drag race.
Click to expand...

I fly one of those odd aircraft that climbs better when I add in negative flaps. I only do this if I'm climbing up to cruise for a X/C.

YES I said NEGATIVE flaps. :eek: Our Maule's have a -7 setting for X/C to improve X/C performance.
 
Don't beavers use a positive flap setting for a normal climb?

I'm still convinced that flaps provide more lift than drag at low flap settings, especially fowler flaps. Once you go past the first 10 or 15 degrees you start adding more drag than lift.
 
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