Landing with speed brakes deployed

[Danb]

I haven’t landed with the speed brake’s deployed but talked with a couple that always landed in that configuration. I was told by the previous owner of my Acclaim that he always used them.

Who  are the long body pilots that land with them deployed and the results. Is float diminished, landing roll any change in handling characteristics. I didn’t see anything in my POH I’d like to know if there is any benefit. The person who purchased my Bravo is being taught landing with them deployed.

D

[Brandt]

I do so occasionally. Especially when landing at a larger airport in which I’ve had to keep my speed up on final. Doing, so was one of the first things I was taught during my transition training. No change in handling, no change in stall speed, obviously less effectiveness as the airplane slows down. But sometimes useful and perfectly acceptable technique. 

[geoffb]

No issue with landing with the brakes deployed.  Can definitely reduce float if you end up coming in fast.  Or if you come in high and don't want to slip.

Does add an extra step to a go-around which is why I don't make it a habit.  If you're on speed, you generally shouldn't need them.

[N201MKTurbo]

I usually put them out after I touch down to shorten the rollout. 

[redbaron1982]

I have done this just by mistake, I'm still sometimes coming in too high or too fast and I pop the speed brakes out to get down/slow. A few times, and I'm ashamed of it, I forgot to retract them. The result was that the airplane didn't want to keep flying as much as it was on the ground more decisively (which is good, as I'm coming in between 75kt to 80kt when landing).

I don't think it is a great practice, as adds more workload in case of a go-around.

[Schllc]

The slower you are going the less impact they have because of the angle of attack of the wing and the air flow.

but like others have mentioned here, it is an excellent way to scrub some speed when you are 10' or less over the runway, and it makes you settle down pretty nice.

After I was very familiar with the mooney landing, I stopped the frequency with which I use them, but they are a great option to have in the bag, if you are coming in a little hot.

 

[PT20J]

@mike_elliott @donkaye curious if this is what you teach?

[ArtVandelay]

I usually put them out after I touch down to shorten the rollout. 

Really?! Their effectiveness seems negligible at landing speeds.

I used them if I’m coming in a little hot, never had to do a go around.

[GeeBee]

Deployment helps get weight on the wheels which increases tire cornering forces (keeps the tires going straight) as well as increases braking effectiveness (Total friction = Coefficient of friction x force applied (I.e. weight on the wheels). Every little bit helps.   I find deployment after touchdown aids controllability on roll out. Tracks straighter, rolls straighter brakes better.

[mike_elliott]

Speed brakes are a tool for the tool box to use if needed. The key is to set up so they are not needed of course.  They don't hurt to land with them or upset the config so significantly to cause issues, but as stated fairly ineffective as you cross the numbers

On roll out, deploy them for the cool factor as you wiz past the FBO. Cirrus guys will drool with envy

[Brandt]

6 minutes ago, mike_elliott said:

Speed brakes are a tool for the tool box to use if needed. The key is to set up so they are not needed of course.  They don't hurt to land with them or upset the config so significantly to cause issues, but as stated fairly ineffective as you cross the numbers

On roll out, deploy them for the cool factor as you wiz past the FBO. Cirrus guys will drool with envy

RE Cirrus.  True, but be careful. Don’t want them to prematurely pop their chute….

[N201MKTurbo]

35 minutes ago, ArtVandelay said:

Really?! Their effectiveness seems negligible at landing speeds.

I used them if I’m coming in a little hot, never had to do a go around.

I usually try to not use the brakes. It shortens the landing roll by 10% -15% or so. Brakes are for runup and hold short lines.

[A64Pilot]

It’s been since 1989 I think when I flew the two M20JAT’s at the School I was at, but we did go around’s with them deployed without incident.

I’m sure there was some performance degradation, but I’m certain the aircraft will pass all Certification maneuvers with either both or one deployed. I know you can’t deploy one but it’s possible one could get stuck so I’m sure the FAA had Mooney demonstrate controllability etc in every possible combination.

I liked them, but we weren’t allowed to use them in our training and we had to drop flaps before gear which made speed control even more challenging, but once you get used to it it’s not hard.

The reason given was they weren’t trying to teach Mooney pilots but Commercial pilots and almost every aircraft out there doesn’t have speed brakes, and you get approach flaps before gear

[Fly Boomer]

2 minutes ago, N201MKTurbo said:

I usually try to not use the brakes. It shortens the landing roll by 10% -15% or so. Brakes are for runup and hold short lines.

I like this plan.  I'm still learning how to keep my size 14 clodhoppers off the brakes.

[N201MKTurbo]

The speed brakes came with the plane. After having them for 21 years, I wouldn't pay to have them installed.

[Will.iam]

1 hour ago, GeeBee said:

Deployment helps get weight on the wheels which increases tire cornering forces (keeps the tires going straight) as well as increases braking effectiveness (Total friction = Coefficient of friction x force applied (I.e. weight on the wheels). Every little bit helps.   I find deployment after touchdown aids controllability on roll out. Tracks straighter, rolls straighter brakes better.

I find retracting the flaps after touch down does way more to get weight on wheels than speedbrakes do to help keep from locking up the wheels especially when braking hard. 

[GeeBee]

13 minutes ago, Will.iam said:

I find retracting the flaps after touch down does way more to get weight on wheels than speedbrakes do to help keep from locking up the wheels especially when braking hard. 

It does, but why not use them both?

[PT20J]

1 minute ago, GeeBee said:

It does, but why not use them both?

Maybe because you need to retract the flaps sooner or later anyway, but the darn speed brakes seem failure prone and VERY expensive to repair? 

But seriously, the Precise Flight speed brakes aren't really spoilers -- they primarily increase parasitic drag, and as such they are most effective at higher speeds (drag is a function of TAS^2). If they had a big effect on lift they would be a problematic for go arounds.

[MatthiasArnold]

I utilize them for steep approaches like circling into runway 09 at LIMG.
Besides supporting speed control in steep descents it also seems to reduce potential floating while landing. 
AFAIK you can go around with SBs extended per M20R POH. 
Good opportunity to look this up, though..

Best,

Matthias
 

[GeeBee]

My view on landing is to get the speed broken down quickly as you never know what awaits you on the other end. Maybe a deer or coyote crossing the runway, maybe slick runway or maybe a brake failure. Get the airplane down to taxi speed quickly consistent with good operating technique so you can roll off into the grass if you have to safely and without a prop strike.

[LANCECASPER]

4 hours ago, Danb said:

I haven’t landed with the speed brake’s deployed but talked with a couple that always landed in that configuration. I was told by the previous owner of my Acclaim that he always used them.

Who  are the long body pilots that land with them deployed and the results. Is float diminished, landing roll any change in handling characteristics. I didn’t see anything in my POH I’d like to know if there is any benefit. The person who purchased my Bravo is being taught landing with them deployed.

D

I use them occasionally to land especially if I find myself a little fast on final. I think it helps with float a little. I think after awhile you get a seat-in-the-pants feel for how final approach is feeling,  and looking outside, if it feels like I need it, I use them.

Coincidentally this last week I re-read a Robert Goyer article in Flying from 15 years ago shortly after the Acclaim S was introduced. Here's what he had to say: "The speed brakes also help in one other respect, in landing. You’ve probably heard that Mooneys are hard airplanes to land, and it’s true. Unless, that is, you do things right, in which case they’re easy to land. The key, as you know if you’ve flown them, is to control your airspeed. On landings where I did this, I was overjoyed with the result. On landings where I was a little fast, the results weren’t pretty. By using the speed brakes, however, the airplane tends to float a lot less. By the end of the week I was using the blades on every landing. With them, speed control is still important, but slightly less so."

Link to the Article: https://www.flyingmag.com/pilot-reports-pistons-mooney-acclaim-type-s/

[Fly Boomer]

2 hours ago, LANCECASPER said:

I use them occasionally to land especially if I find myself a little fast on final. I think it helps with float a little. I think after awhile you get a seat-in-the-pants feel for how final approach is feeling,  and looking outside, if it feels like I need it, I use them.

Coincidentally this last week I re-read a Robert Goyer article in Flying from 15 years ago shortly after the Acclaim S was introduced. Here's what he had to say: "The speed brakes also help in one other respect, in landing. You’ve probably heard that Mooneys are hard airplanes to land, and it’s true. Unless, that is, you do things right, in which case they’re easy to land. The key, as you know if you’ve flown them, is to control your airspeed. On landings where I did this, I was overjoyed with the result. On landings where I was a little fast, the results weren’t pretty. By using the speed brakes, however, the airplane tends to float a lot less. By the end of the week I was using the blades on every landing. With them, speed control is still important, but slightly less so."

Link to the Article: https://www.flyingmag.com/pilot-reports-pistons-mooney-acclaim-type-s/

Goyer also confirms that the speed penalty for LOP makes it essentially useless:

It seems absurd, I should add, to apologize for 236 knots, so let me point out that 236 knots made me very happy indeed. And at 50 degrees lean of peak, I was still seeing 230 knots at 21 gph

 

[donkaye]

I, too, have written an article on speed brakes that can be found on my website at https://donkaye.com/useful-aviation-articles.  That article pretty well describes how to use speed brakes.  I do automatically "pop" them on touchdown.  I have found them be effective from touchdown speed to about 75% of touchdown speed.  Below 200 feet, if you are too fast for the runway length, I'd recommend going around rather than applying the speed brakes.  You will get an immediate 200 ft/min increase in descent rate that could slam you into the ground at that altitude.

[LANCECASPER]

1 hour ago, Fly Boomer said:

Goyer also confirms that the speed penalty for LOP makes it essentially useless:

It seems absurd, I should add, to apologize for 236 knots, so let me point out that 236 knots made me very happy indeed. And at 50 degrees lean of peak, I was still seeing 230 knots at 21 gph

 

IMHO the Acclaim begs for LOP, since you can still get amazing speeds and range at 15.5 GPH at LOP. Or you can get max POH speeds if you're OK with a high fuel burn and you don't like LOP. It runs very smooth and cool at both ends of the spectrum and everywhere in-between.

It's like having an Encore, an Ovation and an Acclaim all in your hangar, wrapped up in one package.

 

[dkkim73]

4 hours ago, PT20J said:

Maybe because you need to retract the flaps sooner or later anyway, but the darn speed brakes seem failure prone and VERY expensive to repair? 

But seriously, the Precise Flight speed brakes aren't really spoilers -- they primarily increase parasitic drag, and as such they are most effective at higher speeds (drag is a function of TAS^2). If they had a big effect on lift they would be a problematic for go arounds.

I'm sorry, as you seem pretty dialed-in aeronautically, but doesn't parasitic drag go up as a higher power than 2? 

The reason that might matter is that those little dudes are pretty small (FWIW I was quoted a very small equivalent flat-plate area of the Type S when clean, so it's a big difference at speed when they pop out) and things are slow in the landing regime. 

Just following on to the discussing of speed brakes vs. true spoilers (the ground spoilers on a big wing will actually result in significant down force as I understand). 

D