Speed Brakes (How To Use?)

[HopePilot]

Okay, so I'm picking up the plane on Monday with the new speed brakes.  Here's my question...when you land with them extended do you have flaps all the way down or partial?  I'm sure it depends, but if were a regular, light wind day.

Any thoughts on how you use them on high wind days, etc. are appreciated.  Thanks!

[scottfromiowa]

Why would you have them deployed to land?  I thought they were used to allow full power descent and avoid shock cooling/major throttle reduction.  Once you are down to pattern why wouldn't you retract them...in case you need a go around you want full power and NO additonal drag, right?

[HopePilot]

My understanding is that with gusty winds people like to land with them deployed (with added power).  It's an issue for me as one of my main destinations is Apple Valley (in the middle of the desert with strong winds).  I've also heard of people deploying them just before flare to keep the plane from floating, but I'm in the learning phase.

 

 

[MooneyMitch]

I might suggest you speak with Don Kaye regarding your questions.  Don is a well respected Mooney flight instructor, living in the San Francisco Bay area.   He is www.donkaye.com also and is always most helpful.  Congratulations on your new speed brakes.  You are going to enjoy them!

[Ned Gravel]

I agree with Mitch.  Flying your Mooney down to the ground without the aid of speedbrakes is important so that you can really appreciate when something is not right.  Whatever you may have heard about speedbrakes, I think you should bounce your ideas off of a really good Mooney instructor before trying them. I do know that our Mooney's are some of the best airframes for landing in gusty and crosswind conditions.  They will only float if we have done something wrong - like too fast across the threshold.

At 50 feet up off the runway on final is also the spot where we may have to get ready to go around if necessary and speedbrakes are not going to help you get over that obstacle causing you to do that.

I could tell you what I may know or think about speedbrakes, but I do not have them on my aircraft and I would only be giving you more stories about them - not the facts.  I really think you need the facts before you use them - and especially before you use them to help you touch down.

[scottfromiowa]

Interesting topic.  Will watch to see what techniques with speed brakes are out there.  I have never flown with anyone that has them either.  I agree that Mooney's are good in the wind (landing config.)

[MooneyMitch]

What I do with my speedbrakes...............I love them!  They are just fun.  Sometimes I come ripping down toward the airport and throw [whoops!] out the brakes just because I can.  Other times, I don't ever use them.  I'll simply slow down with the normal throttle, rpm and gear technique. 

I have used them to slow down for turbulence and I have not used them for that.  I have landed with them also and most of the time not.   I have used them to drop like a rock with full power and sometimes with little power. 

As far as a go around...............yes, it might be a bit more to do during that proceedure and I'll bet other's will have opinions on that.  There is that little button on the side of the yoke, and when you depress it, the speed brakes are completely retracted in 2 seconds or less. 

Proper proceedure?  Not sure if there is one but Don will fill us in.  In fact, this may be one of those Rod Machado "so what" topics.  Point is, for me, they are great to have and use as I see fit.

[mooneygirl]

I for one am so happy that your Victor has his speed brakes installed.  I am sure that you will get lots of advise and practice. I would also recommend Trey Hughes from MAPA.   I seem to remember an article about the use of speed brakes in the past year or so.  trey_hughes@sbcglobal.net

[HopePilot]

Thanks guys, I'll see if I can get that article.

[MooneyMitch]

Don Kaye will be at LASAR 35th tomorrow.  We'll discuss this topic with him and report back. 

[DaV8or]

I'm keeping an eye on this thread too. Speed brakes are on the list of potential mods in the future and I'd like to see what your real world experience with them is. I rode in a Mooney with speed brakes once, older units with mechanical cable operation and I thought it was the cat's meow!

[Mooney13]

Like Mitch.. I don't really have a set standard on when I use my speed brakes. I just finished my IFR rating and did not use them much at all while training becuase of the slower speeds when in the various approaches. The most common time for me using them are for 1. losing altitude whithout gaining too much speed  2. helping me get to my landing gear speed sooner (then the real speed brakes come out) 3. Landing under a little more power (although below 90kts, I am not sure they really do too much) 4. Flying closer to the destination airport at higher speeds ..... Im sure there is more I am forgetting and more I can learn about them and look forward to hearing others stories...

In general, I like having them there....many times I dont even bother with them, but when I need them, they sure com in handy...

[FlyDave]

Speedbrakes were in my plane when I bought it a few months ago. When I was first learning to fly the airplane they were more of a security blanket for me in VFR conditions. Now, after more than 100 hours in the airplane I seldom, if ever, use them in VFR conditions. I believe the Mooney was built for speed. Planning your descents appropriately lets you take advantage of that speed. You'll go faster in a descent than you will cruising at 155 Kts. and using the speed brakes 12 miles from your destination.

I do use them in IFR conditions where you don't always get the luxury of descent planning. The ability to turn the airplane into an elevator "Going Down" with the push of a button keeps both myself and the controllers happy.

[MooneyMitch]

I will land at Lakeport [LASAR 35th] with the speedbrakes deployed and see what reaction I get on the ramp!

[rbharvey]

I have found them useful for two reasons:

-IFR descent when flying high altitude where ATC usually expects/plans a 1000 FT/M descent for you. Hard to stay below VNE without them deployed/and keep engine power up > 20 inchs

-aid in slowing down when; keeping speed up in larger high density airports and hitting unplanned turbulence/forced cloud penetration

 

I have not found any more useful than std technique for gusty/x wind landings or avoiding bounces. All those are handled best by flying the numbers for your airframe and not coming over the threshold at 80+ knots :-) I have not found them good for lift control on approach (like direct lift control on the F14, where you can easily variably roll them out and in) and again not necessary if flying a Mooney like you are supposed to!

[DaV8or]

Quote: Mitch

I will land at Lakeport [LASAR 35th] with the speedbrakes deployed and see what reaction I get on the ramp!

[MooneyMitch]

Quote: DaV8or

Perfect application for them! I have flown into Lampson many times and coming direct from the south, you cross over the mountains and then bomb straight down for the field if you want to go direct. Pretty easy in a Warrior. With my Mooney, I will not go direct and I will fly a wide hooking approach over the lake so I can slow down and not shock cool. With the speed brakes I think you could safely go direct.

[fantom]

I've had the since day one, 15 years ago, on my J....rarely use them. Ok to slow down quickly , and stabilize a bit in very strong winds. They have zero effect in ground effect. Best use....looks cool to the unsuspecting, popping up on the ground.  

 

[M016576]

I've never used speed brakes on a prop aircraft before, but I imagine they would be good for penetrations and quick descents.  I don't know about the added stability in windy conditions, that may or may not be true....

In the hornet, if we have a crosswind, we leave the speedbrake in, as the huge barn door between the tails tends to cause instability on the rollout and can lead to overcontrol... I know, not the same as a mooney!

When I flew the goshawk and buckeye, we would keep the speedbrakes deployed during landing to keep the engines spooled up higher just in case we boltered (went around) at the carrier.  Some other carrier based aircraft do(did) the same.  The hornet and the super hornet do not, as the digital fly by wire flight controls and automated flap settings allow for slower approaches with higher power settings by way of aerodynamics.  I know that C-2 and E-2 aircraft on the ship do not have speedbrakes or need them, as power is instantaneously available (the motor is running at a constant RPM). 

My gut says that you wouldn't buy much, if anything, by keeping the boards out on a (proper) landing in a mooney.  If you're coming in hot and deploy them, then it's just one more thing to remember that could impact your habit patterns crossing the threshold.  But then again, I've never talked to a mooney IP about them, since mine isn't equipped!

-Job

[HopePilot]

Does anyone use them to help braking during the rollout?  If so, how much does it reduce it?

[carusoam]

To improve braking we have a few choices.

[1] good tires and brakes - used smoothly and strongly

[2] pull back on the elevator - aerodynamic braking, works pretty well, also puts more pressure on the mains.

[3] raise the flaps - helps keep you planted once on the ground, some use it to minimize float (I have not).

[4] extend the speed brakes - They could remove a very small amount of lift. These are not barn doors.  Proper use will get you to the right numbers beforehand.  They are really good when altitude is higher than desired.

[5] raise the gear......not recommended accept for very special circumstances.  This could happen in all of the confusion of pushing and pulling buttons and levers in the last few moments prior to landing. 

Improved braking comes after being firmly planted on the ground.  Get on the ground by flying the numbers. Then dump excess lift to stay on the ground and allow the brakes to work.

More questions for your consideration.....

Is anyone able to measure actual landing roll out?  Or take-off distance for that matter?  GPS function for this?

Can we change the name from "speed" brakes to "altitude" brakes.  I use them to remove excess altitude, not so much to remove excess speed.....

Respectfully submitted,

-a-

[M016576]

-a-

        Not actual landing roll out... or TO distance for that matter, but I do keep the runway boards in sight for an estimation... obviously, smaller airports don't have these, but if you do, you can guesstimate pretty well using them...

I'd imagine that due to speedbrake placement on the mooney (on the upper wing) that they would have a spoiler affect on deck, removing a little lift and thus putting some more pressure on the mains (making the braking action more effective).  My take on it:  If you've got them, and rollout distance is an issue, the only reason to not extend them would be because you'd be afraid that you'd forget to retract them in case of a go-around.... 

If I departed the runway and didn't extend the speedbrakes, I'd probably always run it through my mind (...why didn't I put out the boards...) whether or not they would have made much difference...

 

-Job

[roundout]

The speedbrakes really don't do much below 90 knots. I used to demo a takeoff with them deployed (use common sense - make sure you have a long runway on a day with enough performance) as people seemed to be concerned about failing to retract them on a go around. Don't get me wrong, in some situations and aircraft failing to retract the boards will get you killed (see AA 757 in Columbia) but in the Mooney it just isn't a big deal. 

Personally, I make it a point to NOT use them at all. I figure if I can manage everything with pitch, power, and planning, I am in tune with the airplane. If I flub something up, I still have the brakes in my back pocket if I need them. 

[MooneyMitch]

Hi Fernando.

Don Kaye says using the speedbrakes in a crosswind will have no advantage and will make no difference either way.  They will not creat a hazard.  He sees no reason to use them on a crosswind landing.  He does use speedbrakes sometimes on rollout to help slow his plane.

He also says speedbrakes do not affect stall speed either.  If you would like futher explanations from Don, he asks that you please do contact him.  He is happy to help.

 

[M016576]

Very interesting, Mitch, about the boards not affecting stall speed! 

My guess on that is......   that the board placement is far enough back along the cordline of the wing that the boundary layer has already seperated from the wings surface well before the point where the speed brake would interfere with the laminar flow.  Since the airflow is already turbulent over the top of the speed brake, the speedbrakes are essentially shielded by the leading edge of the wing, thus negating their spoiler effect....

In essance, a "true" speed brake is one that would extend from the fuselage (ie no interference with the wing's lift).  The mooney's boards are more of a spoiler, from the looks of them:  an interference that disturbs the airflow over the wing, thus negating lift. 

I've got a question for those that have boards on their mooney's-> when you deploy the boards, do you feel an attitude change in the aircraft, or are they essentialy statically nuetral?  Thanks!

-Job