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How do you use your Speed Brakes?


MBDiagMan

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I am just now beginning to use the speed brakes for one little thing.  I am curious to hear when and in what situation others use them.

My little thing I use them for is, when slowing down for the FAF, I deploy the brakes as I slow down to gear speed, then I basically trade the brakes for the gear down. 

How and when do you use them?

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When ATC keeps me high or forgets to give me lower, pop them out for an extra 500 FPM decent with the same power setting.

Or to slow down while entering the pattern to get to gear speed (140 IAS in my plane)

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7 minutes ago, Bryan said:

When ATC keeps me high or forgets to give me lower, pop them out for an extra 500 FPM decent with the same power setting.

Or to slow down while entering the pattern to get to gear speed (140 IAS in my plane)

Same here; both situations.

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19 minutes ago, MBDiagMan said:

I am just now beginning to use the speed brakes for one little thing.  I am curious to hear when and in what situation others use them.

My little thing I use them for is, when slowing down for the FAF, I deploy the brakes as I slow down to gear speed, then I basically trade the brakes for the gear down. 

How and when do you use them?

I often do that when in a long vectored ILS approach with jet traffic. By the time you are descending you are still doing 160kts and accelerating. Pop the brakes out over the FAF, gear out 10 seconds later when own to 140 and put them back in. Works great.  That is really all I use mine for now too.  I experimented with them on final, landing with them, etc to see how the plane reacted also.

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I use them for all of the same above stated reasons.

However I also use them in one more situation that is really nice.

On a hot bumpy day coming into your destination trying to stay as high as you can for as long as you can for ride quality.

They sure help when it comes time to nose down through the rough an puffys to minimize time to come down, while keeping power(an temps) up.

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The few times I use them usually are.

-When I’m behind the plane

-asked to keep the speed up on final and need to get to gear extension speed

-turbulence!

-hot days and I float forever on landing

-after crossing the Sierras and need to drop 10K feet ASAP to land.

-when I want to land gear up (they create enough drag to give you the sensation of the gear being down and have to add enough MP to prevent the gear horn from going off)

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We have a mountainous Class B to drop down after that is similar to being left high by ATC...

It can also be helpful when energy in the traffic pattern has been misjudged... a tendency to be slightly high and or fast with a heavy plane is easy to put back on target at the push of a button or two pushes...

Generally use them to remove energy from the system... when needed...

The drive for efficiency is great when you have everything executed to plan.... remove the excess energy when the plan gets away... :)

The nice thing about the brakes...

  • they are located to not need trim changes like adding flaps does...
  • Unlike flaps, they can be stowed and re-deployed as needed... the lift disturbance is different than raising flaps... flaps move the center of lift, brakes leaves the Cl in the same place...
  • Don’t forget them, because your elevated sink rate can be problematic if you are thinking they are stowed...

PP thoughts only, not a CFI...

Best regards,

-a-

 

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I’m only a few weeks into owning my Bravo but I think there might be something wrong with it because it doesn’t want to slow down ;).

I’ve found the speedbrakes most helpful on the last portion of my descent when I encounter some turbulence and don’t want to pull up or cool the engine by cutting power.  Unfortunately, my right speedbrake just stopped working so I have send it back to precise flight for some maintenance...

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5 hours ago, kmyfm20s said:

-hot days and I float forever on landing

Please be careful using speed brakes when landing.  I never extend the devices to land in case I need to go around.

A few days ago I had to suddenly go around below 50 feet at my home field on a hot day.  Most go arounds are unexpected as this one was. My hands and feet were full enough dealing with the go around from such a low height without having to worry about speed brake retraction and worse if they fail to retract.

I did read somewhere a long time ago our speed brakes are supposed to be ineffective at landing speed, however I do not want to test this concept during a go around on a hot day or any day when you need everything going for you. @donkaye doesn't advocate using them in certain landing conditions either.

I use mine at altitude to either slow down or steep descents and believe this is what they were designed to do and the devices do it well.   

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15 minutes ago, Mooney in Oz said:

Please be careful using speed brakes when landing.  I never extend the devices to land in case I need to go around.

A few days ago I had to suddenly go around below 50 feet at my home field on a hot day.  Most go arounds are unexpected as this one was. My hands and feet were full enough dealing with the go around from such a low height without having to worry about speed brake retraction and worse if they fail to retract.

I did read somewhere a long time ago that our speed brakes are supposed to be ineffective at landing speed, however I do not want to test this concept during a go around on a hot day or any day when you need everything going for you. @donkaye doesn't advocate using them in certain landing conditions either.

I use mine at altitude to either slow down or steep descents and believe this is what they were designed to do and the devices do it well.   

Speed brakes are located in the area of boundary layer separation at climb AOA. The reason they work for Don right after touchdown (I’ll take his word for it) is that the wing is at low AOA on roll out. Go out and give it a try, your bird will climb just fine with them deployed.

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Edited by Shadrach
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3 hours ago, Mooney in Oz said:

Please be careful using speed brakes when landing.  I never extend the devices to land in case I need to go around.

A few days ago I had to suddenly go around below 50 feet at my home field on a hot day.  Most go arounds are unexpected as this one was. My hands and feet were full enough dealing with the go around from such a low height without having to worry about speed brake retraction and worse if they fail to retract.

I did read somewhere a long time ago our speed brakes are supposed to be ineffective at landing speed, however I do not want to test this concept during a go around on a hot day or any day when you need everything going for you. @donkaye doesn't advocate using them in certain landing conditions either.

I use mine at altitude to either slow down or steep descents and believe this is what they were designed to do and the devices do it well.   

I’m not sure I would buy speed brakes if I had the choice but since I have them they are a tool to be used in the right situation. Landing gear down is still your biggest drag item.  A few of the things I listed above are why speed brakes are not good. Your plane needs to be able to take off with the speed brakes deployed to be certified. Not that you wouldnt spooked on a go around and not getting the lift your used to. It is kind of like the first time you did a go around in a trainer plane with the carb heat on, we all figured it out. When I want to intentionally land short working the speed brakes and flaps easily reduce the length by 200’.  I don’t recommend using speed brakes to compensate for bad technique. 

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14 minutes ago, kmyfm20s said:

I’m not sure I would buy speed brakes if I had the choice but since I have them they are a tool to be used in the right situation. Landing gear down is still your biggest drag item.  A few of the things I listed above are why speed brakes are not good. Your plane needs to be able to take off with the speed brakes deployed to be certified. Not that you wouldnt spooked on a go around and not getting the lift your used to. It is kind of like the first time you did a go around in a trainer plane with the carb heat on, we all figured it out. When I want to intentionally land short working the speed brakes and flaps easily reduce the length by 200’.  I don’t recommend using speed brakes to compensate for bad technique. 

I agree that from a practical standpoint the gear is your highest drag item.  I would posit that it stands to reason that technically there are AOAs (read negative) at which speed brakes are more effective  than the gear. 

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4 hours ago, Davidv said:

I’m only a few weeks into owning my Bravo but I think there might be something wrong with it because it doesn’t want to slow down ;).

I’ve found the speedbrakes most helpful on the last portion of my descent when I encounter some turbulence and don’t want to pull up or cool the engine by cutting power.  Unfortunately, my right speedbrake just stopped working so I have send it back to precise flight for some maintenance...

If you pull back on the yoke the plane will slow down.  If you pull the throttle out the plane will slow down.   If you put the gear out the plane will slow down.  It is all about energy management.

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I don't have speed brakes on our Mooney, but I've flown a couple big airplanes that did.

As Don said, except in a few specific circumstances that make you want to stay high as long as possible due to weather, the use of speed brakes means either you screwed up or poor planning.

If I pull the power back to 2200 RPM and 15", my clean M20J will lose 10 KIAS every 1/2 mile.  So I can go from 150 KIAS to a reasonable 120 KIAS before I lower the gear in about 1.5 miles.  I also know that at idle power I can go from 120 KIAS with the gear down to 65 KIAS with gear and flaps while descending down a 3 degree glideslope in about 1.5 miles.

Also, as Don said, except as noted above, if you use speed brakes to slow down, you could have just pulled the power earlier, saved some gas, and arrived at the same point at the same speed.  Granted, it won't be much gas, but it will be some gas.  And one of the useless things in aviation is gas you don't have.

Also, if you get used to using speed brakes as part of your normal operation, you won't have anything left to bail you out when you screw up and get behind.

I can do the same thing in our Mooney that we used to do in the DC9.  Slow down to go down.  If we were high and fast on final, we would level off and configure while at idle power.  Once we were full dirty we could start the descent at idle power until we were caught up and then add power to maintain speed while we captured the glidepath.

And remember, if ATC asks you to do something you aren't comfortable with you can always say "unable".  The downside is it might earn you vectors off the final and a trip around the circuit while they sequence you back into the flow.

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The only addition to the comments above is my use of speed brakes when asked to expedite a descent for a portion of it and when I was not IR and had flight following tell me to immediately descend as someone popped up on their screen on a converging path with me.

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I have speed brakes and use them whenever I feel they might be useful to the current situation.

As Don says, there are times when it's not efficient to use speed brakes. But I don't see any situation where it's dangerous to use speed brakes.

Like @Bryan said, it's useful to know how your Mooney will react in all different configurations and circumstances. Taking off with speed brakes deployed is no more of an issue than forgetting to raise the gear and wondering why your climb rate is shit.

As with just about everything with our airplanes, I'm always learning and trying to be smoother, more efficient, and further in front of the airplane. And that includes the use of speed brakes. But they are not going to kill you and if you have them, don't be afraid to use them.

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Had an electrical issue and had a single speed break deploy on takeoff. When I do the controls free and correct the speed break deployed on one side due to the placement of the switch on the yoke. The break that deployed was on the down aileron side and I was looking for an up aileron on the other wing so didn't see it since the break was stowed on the wing under observation. After I rotated, really hard yaw into the break... though I got slammed with a X-wind gust, but it persisted and stabilized...didn't feel like a gust. Immediately lowered the nose to keep airspeed and saw the single break out and stowed it. I have now modified my pre-takeoff list to check both breaks. Sent units back to precise flight for overhaul (obviously). When landing with them out with close to no-wind, I can land about on the numbers and stop at the indicated spot to make the first turnoff. It was experimental, 80MPH over the fence and heavier breaking.  You have to drag it in under power, so I thing this would probably be something to think about to limit ground contact energy in making an off-field landing. Wouldn't & don't do it or recommend it for normal course of ops , but was good to know what the plane will do. 

 

1579578359_ScreenShot2019-02-14at11_46_21AM.png.e29243a3e0b778e1e24570082e2bb419.png

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Good idea for speed brakes.... add them to the check list for pre-takeoff items... up and down... :)

 

effectiveness of the brakes... very much related to airspeed... at or near Vne you can feel how well they are working...

At traffic pattern speeds... you know they are working, but have to check ASI, VSI, or altimeter to know how much they are working....probably won’t feel them...

PP thoughts only, not a CFI or mechanic...

Best regards,

-a-

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