Speaking of landings...with speed-brakes deployed.

[Stephen]

Interesting thread on landings going on. To avoid a thread-hijack, I started this one as a spawn-off. 

The mechanic who did my annual this year has a mooney as his personal plane. He recommended that I try landing with the speed breaks deployed. He said it makes the mooney land like a 172. After trying it, I don't entirely disagree; it seems to significantly change the character of the aircraft. I would like to hear from those who have tried this in their aircraft and wring out your thoughts on the practice.

 

I think before someone does this for the first time, you should probably get a good excess of altitude and be familiar how having your speed brakes deployed in landing configuration changes the speed and symmetry of your stall. Also, this is one more thing to remember on a go-around, but as a tool for certain situations: 

 

Have you done it?

In what precise configuration (wrt flaps etc)

Do you do it / if so when  and in what conditions?

 

I know many don't have speed brakes, although my F has them I think I used them about 2-3 times in my first year of ownership (trying them out, getting through a hole in an overcast etc). 

 

Thoughts?

 

 

 

[carusoam]

Stephen,

I’m a full flaps kind of guy.... prop full in and gear down... braking is happening pretty strongly under these conditions....with the runway made, the MP gets pulled....

I Follow the procedures to the best of my abilities...

If coming in too fast or too high... the speed brakes get used to remove some of the excess energy.

The inherent challenge is the speed brakes are less effective, the slower you are going....

Overall, i am still controlling speed and altitude with attitude and power...

if i am 5 kias faster than I want... the speed brakes come out....

10kias too fast and a couple hundred feet high... the speed brakes are probably not going to be helpful enough....

The challenge becomes changing configurations on final approach is not a really good idea...

generating 1000fpm descent rates would be a bad idea normally...

Its a pretty small configuration change at landing speed.  A small tool that can be used...

Just not a big enough tool to make it part of plan A.

Plan A, maintain speed and altitude targets around the traffic pattern.

Pp thoughts only, not a CFI...

Best regards,

-a-

[gsengle]

I disagree. They shouldn’t do much at landing speeds and angles of attack. In fact they do so little that to certify them they confirmed that even at Vx and Vy on a go around they don’t do much. They require lower angles of attack/higher speeds - look at their size and position back on the wing...

Won’t hurt to leave em out, but never seemed to be much of a difference in my Ovation.


Sent from my iPhone using Tapatalk

[Shadrach]

Interestingly enough a IA/ATP I know said the same of my F model ( no s brakes) when we did a steep, slow (on the numbers), full flaps approach to a 3000’ runway and turned off before the half way point. At the time he was flying a well equipped company M20M. He was type trained in it by one of the national currency mills. 3500’ was the edge of his comfort level. He was taught to cross the numbers at 90kts.

Edited September 7, 2018 by Shadrach

[Shadrach]

2 minutes ago, gsengle said:

I disagree. They shouldn’t do much at landing speeds and angles of attack. In fact they do so little that to certify them they confirmed that even at Vx and Vy on a go around they don’t do much. They require lower angles of attack/higher speeds - look at their size and position back on the wing...

Won’t hurt to leave em out, but never seemed to be much of a difference in my Ovation.


Sent from my iPhone using Tapatalk

This^^^^^^

[Stephen]

Really good feedback so far... One thing I notice there seems to be some effect on approach that is definitely lessened due to the lower approach energy and higher angle of attack......... but (for those of you who are comfortable with the practice) notice what happens when they are deployed and the mains contact ....the angle of attack comes out due to the nose coming down.. then they get full profile efficacy again. It really seems to make the aircraft 1) plant firmly and 2) slow down noticeably more quickly making the first turnoff or dealing with more authority on a short runway. 

[carusoam]

Negative captain....

once on the ground the added braking is like sticking your hand out the window....

Your hand will notice it, but the plane will need a WAAS source and cloudahoy to measure the change in braking distance....

Essentially, the speed brakes are like cutting of some wing length... with a speed variation... find the video of speed brakes deployed in the rain around here somewhere... to see how effective they are at affecting the path of air and the effect they have...

where the braking comes from is the needed increase in AOA... as if you were flying a shortwing Mooney....

once on the ground the AOA becomes un-important since you are no longer generating lift (sort of)...

The airflow disturbance (at cruise speed)is about a foot to either side of the brakes... sort of like cutting 4-6’ off the effective wing length...

at high speeds generating enough lift to support the plane by using additional AOA... they are very effective brakes...

Best regards,

-a-

[M20F-1968]

Landing with speed brakes out seems to work best when you want to carry more power due to crosswinds, turbulence, etc...  When you use them you will want full flaps, gear and a dirty plane so you can add more power.  You will still configure the plane and land it in the same way, just with more power.  The plane feels heavier, and more stable.  The downside is it is less efficient and without crosswinds or conditions which make you want more power, conventional landings feel more elegant.

The plane will still do a go-around initially with gear, full flaps and speed brakes, but you need to keep the nose flatter and keep the speed up while still climbing.  The speed brakes can be brought back in quickly, gear and then flaps (or raise 1/2 flaps, gear up, then the rest of flaps).

John Breda

[carusoam]

The nice part of using speed brakes...

They are easy to deploy, and retract....

The electric powered ones operate quickly...

They are fully visible to see what position they are in...

 

One day you will get the asymmetrical deployment caused by a worn clutch...

This is for your complete knowledge of how effective they are...

Getting them OH’d takes about a week...

Best regards,

-a-

[Stephen]

10 minutes ago, carusoam said:

Negative captain....

once on the ground the added braking is like sticking your hand out the window....

Your hand will notice it, but the plane will need a WAAS source and cloudahoy to measure the change in braking distance....

Essentially, the speed brakes are like cutting of some wing length... with a speed variation... find the video of speed brakes deployed in the rain around here somewhere... to see how effective they are at affecting the path of air and the effect they have...

where the braking comes from is the needed increase in AOA... as if you were flying a shortwing Mooney....

once on the ground the AOA becomes un-important since you are no longer generating lift (sort of)...

The airflow disturbance (at cruise speed)is about a foot to either side of the brakes... sort of like cutting 4-6’ off the effective wing length...

at high speeds generating enough lift to support the plane by using additional AOA... they are very effective brakes...

Best regards,

-a-

Ok, fair enough, they dont seem to have much surface area (to generate significant drag at rollout speeds) for sure, I just seem to notice a shorter rollout

[Stephen]

I have had asymetric deployment due to a bad clutch and had to have them rebuilt this annual, no T shirt unfortunately ... much more interesting was that I found out they were deploying assymetrically due to inadvertant deployment during takeoff. That was definately an attention getter. Verifying that they are stowed is now on my pre-takeoff checklist. I think I hit the yoke switch during the controls free and correct check and was looking at the aileron on the wing that the SB didnt deploy on.

[carusoam]

One way they could decrease your landing distance....

It is like dumping the flaps at touch down....

Kill all the remaining lift, so all weight is transferred to the wheels...

Add speed brakes, Pull all the way back on the elevator....

apply the brakes, don’t lock the wheels....   

This is about shortening the transition from a flying machine, to a ground bound machine...

It is easy to lock the brakes if the wings are still generating lift...

 

Don’t forget... hitting switches while landing can have some disastrous side effects....

aka distraction...

Best regards,

-a-

[Stephen]

5 minutes ago, carusoam said:

One way they could decrease your landing distance....

It is like dumping the flaps at touch down....

Kill all the remaining lift, so all weight is transferred to the wheels...

Add speed brakes, Pull all the way back on the elevator....

apply the brakes, don’t lock the wheels....   

This is about shortening the transition from a flying machine, to a ground bound machine...

It is easy to lock the brakes if the wings are still generating lift...

 

Don’t forget... hitting switches while landing can have some disastrous side effects....

aka distraction...

Best regards,

-a-

Good advice Anthony, thanks.

[carusoam]

Check your pre-takeoff Check list....

They get deployed and retracted about the same time you are checking airlerons...

No surprises!

-a-

[Stephen]

17 hours ago, carusoam said:

Check your pre-takeoff Check list....

They get deployed and retracted about the same time you are checking airlerons...

No surprises!

-a-

I was supprised, thought I had been slammed by a really bad crosswind , but it was too steady, I instantly lowered the nose to get the speed up until I saw the RT wing brake up and retracted it. Bag of luck down by X, bag of experiece up by Y.

[carusoam]

Wing Brake up... a challenge that can be recovered from...

wing break up... typical of flying into a tornado....   

 

These are my usual spelling errors. Happy to share the challenge! 

-a-

[RobertGary1]

At landing speed I’ve never noticed any difference. They only really do anything when you’re fast. 

-Robert

[StevenL757]

18 hours ago, Stephen said:

The mechanic who did my annual this year has a mooney as his personal plane. He recommended that I try landing with the speed breaks deployed. He said it makes the mooney land like a 172. After trying it, I don't entirely disagree; it seems to significantly change the character of the aircraft. I would like to hear from those who have tried this in their aircraft and wring out your thoughts on the practice.

I think before someone does this for the first time, you should probably get a good excess of altitude and be familiar how having your speed brakes deployed in landing configuration changes the speed and symmetry of your stall. Also, this is one more thing to remember on a go-around, but as a tool for certain situations: 

Have you done it?  In what precise configuration (wrt flaps etc).  Do you do it / if so when  and in what conditions?

I know many don't have speed brakes, although my F has them I think I used them about 2-3 times in my first year of ownership (trying them out, getting through a hole in an overcast etc). 

Thoughts?

Honestly, if I wanted my Mooney to land like a 172, I'd have bought a 172....I like to land my Ovation like, well, an Ovation.  With respect to your mechanic, I'm not sure why he recommended what he did, nor would I ever feel compelled to try.

As far as landing with them deployed, it's a non-event, and depends on conditions.  I've used them in all flap configurations and various power settings, and like @gsengle noted, they are less-effective the slower the touchdown speed.  I have, however, noticed that the stronger the headwind/quartering headwinds I encounter, the more effective they are in the flare and touchdown phase.  I typically see little effect from using them in winds less than ~5-7 knots, or in direct crosswinds.  Agree that if you need to attempt a go-around, it's one more thing to remember.

Steve

[Stephen]

17 hours ago, carusoam said:

Wing Brake up... a challenge that can be recovered from...

wing break up... typical of flying into a tornado....   

 

These are my usual spelling errors. Happy to share the challenge! 

-a-

Ya caught me read handed 

[PaulM]

I have started to use the speed brakes for landing on the approach to 1N7 runway 25.   There are trees (one in particular) that are right in the standard glide path dead center of the final approach.  You already need to be on speed and aiming for the end of the runway. 

One twilight (not yet passenger carrying night) I watched the runway lights start to flicker (we know why) and caught that tree just in my landing lights.   I'm sure I was lower due to the black hole nature of the night approach. 

With the speed brakes out, I can fly a much steeper base to final approach and greatly increase the safety margin over the trees that are not visible at night. 

I don't use them anywhere else, only for where I know there is a steep approach needed. 

I took an IPC with an instructor that liked using(always used?)  the speed brakes on the ovation they had on part 135, because "It makes it land like a piper"... He wasn't "up" on the mooney, theirs was a g1000 that still had the original 2006 software (-26?).   I had to show him the newer features of the 2008 (-30) code. 

Edited September 7, 2018 by PaulM