Speed break

[ChristianGodin]

I read the following somewhere:

"Speed brakes are not the most desirable system on an aircraft. The use of speedbrakes in a large aircraft is primarily used to increase descent rate, something that if done in a Mooney, will pop your eardrums out. If they are deployed to slow down, it is probably due to an inefficient descent and approach. With a properly planned descent profile and deceleration management, by the use of establishing target gates, speedbrakes would not be required. Speedbrakes aren't even supposed to be used in icing conditions. Some Mooney pilots equipped with TKS have deployed the speedbrakes to rapidly descend thru the icing layer, then have gotten a huge surprise when they would no longer retract. The Mooney speedbrakes have been plagued with problems. The earlier systems were the worst as they worked on vacuum pressure but they were easy to rig and maintain. Later Mooneys changed to electric clutches. Fewer problems, more difficult to rig the cables and very expensive clutches. Another problem is that it doesn't even have an automatic stow system when the power lever is slammed forward as in the case of a go-around. So when would you really really need speedbrakes... when ATC tells you to keep the speed up on approach, until a point when you have to slow down with little nautical real estate to get the aircraft into approach config.....and that would happen when one is flying an approach at some airport catering to large aircraft....but then, advancing the prop lever to flatten the pitch will have a greater effect than the speedbrakes. This system should not be factored in to the selection of an aircraft."

I would like to get your thoughs. Thank You.

[N201MKTurbo]

When you are approaching KSNA IFR from Phoenix you will be at 8000 feet crossing Santiago peak. They then vector you for the ILS and ask you to decend to 3500 feet in 12 miles. The speed brakes help.

[David Mazer]

It seems the speed of the faster Mooneys is faster than the original design expectations.  It is very easy for me to be too fast for the plane Vne when coming into any congested area or any area near hills.  Without speedbrakes I would need to request deviations of many miles.  I'm not sure how ATC would respond but I'm certain of how the terrain would respond.  I've had a couple issues with the speedbrakes but I find them worth the effort.

[Cruiser]

http://www.planeandpilotmag.com/aircraft/modifications/flying-with-speed-brakes.html

[gsengle]

Speed brakes are a must have on my Ovation, and I suspect all big engined Mooneys. An easy way to think about it is this - you can slow down in a Mooney and you can descend in a Mooney, but you can't do both at the same time. This becomes a problem when you are trying to get down to gear or flap extension speeds on approaches where you cannot level off.

 

I don't use my speedbrakes all the time, I prefer to plan my descents and thus not waste fuel.  But you don't always get it right, and certainly terrain and ATC can make the speedbrakes even necessary.  What do you do when you hit the FAF and you arent down to flap speeds or worse yet gear speeds?  You either use the brakes or you go around.

 

 

I read the following somewhere:

"Speed brakes are not the most desirable system on an aircraft. The use of speedbrakes in a large aircraft is primarily used to increase descent rate, something that if done in a Mooney, will pop your eardrums out. If they are deployed to slow down, it is probably due to an inefficient descent and approach. With a properly planned descent profile and deceleration management, by the use of establishing target gates, speedbrakes would not be required. Speedbrakes aren't even supposed to be used in icing conditions. Some Mooney pilots equipped with TKS have deployed the speedbrakes to rapidly descend thru the icing layer, then have gotten a huge surprise when they would no longer retract. The Mooney speedbrakes have been plagued with problems. The earlier systems were the worst as they worked on vacuum pressure but they were easy to rig and maintain. Later Mooneys changed to electric clutches. Fewer problems, more difficult to rig the cables and very expensive clutches. Another problem is that it doesn't even have an automatic stow system when the power lever is slammed forward as in the case of a go-around. So when would you really really need speedbrakes... when ATC tells you to keep the speed up on approach, until a point when you have to slow down with little nautical real estate to get the aircraft into approach config.....and that would happen when one is flying an approach at some airport catering to large aircraft....but then, advancing the prop lever to flatten the pitch will have a greater effect than the speedbrakes. This system should not be factored in to the selection of an aircraft."

I would like to get your thoughs. Thank You.

[Bob_Belville]

This has been discussed, probably several times. Brakes on my old E with Vlg @ 120 (104k); Vfe @ 100 (87k); Vno @ 150 (130k); and Vne @189 (164k) come in handy when terrain, clouds, or ATC requires a descent rate of more than about 500 fpm. I suppose that is about 1 flight in 10 for me with my home aerodrome about 6000 below the MEA 20 miles to the west.

[WardHolbrook]

Speed brakes are great tools and pretty much a necessity on many airplanes. Life would be a lot more complicated, in the jets I fly for a living, without them. The higher your fly, the faster you go, and the greater the margin you have between cruise, pattern and gear / flap speeds the greater the need for them. On slower, normally aspirated aircraft that are normally flown at low altitudes there is normally little or no need for them. As you climb the ladder, the usefulness of speed brakes increases. If you're considering them on your Mooney M20J I would simply ask myself, based upon my typical flight, how often would they have been helpful? They're like TKS systems - if you live in Phoenix and spend 99% of your time flying in the SW you probably wouldn't gain much utility by having FIKI certification. If you live in Minnesota your answer might be different. Same thinking applies to speed brakes. If you need them for thy type of flying you do, they're very nice to have and worth the expense. if you don't, they aren't. 

[AndyFromCB]

When you fly like a turboprop (M20K, M20M, Acclaim), the ATC expects you to act like a turbo prop plus nobody ever talks about the comfort they can provide by staying up high where it's cool and smooth for as long as possible and then slam dunking it at -2500fpm few miles out. I never find ears to be a problem with experiences passangers who know what to do to continue clearing their ears. Many here fly to achieve maximum mpg, I like speed and comfort.

[Piloto]

On a ferry flight from LPAZ to CYYT I accidentaly pushed the speed brakes button instead of the microphone button. This caused the speed brakes to deploy but was unable to retract due to icing. This nornally is not a major issue except when you are over the North Atlantic against a 40kts headwind with no much fuel reserve. I recalculated my range and found that I will be swiming toward St. John's. To retract the brakes I tried this: I banked the plane to 70 deg and pulled hard on the yoke to create a high G condition for about one turn. To my relief the blades came down and was able to regain normal speed. After this I pulled the speed brakes CB to insure no future deployment. My lesson to this is to pull the speed brakes CB if icing is to be encountered.

 

José 

[chrisk]

First, I am not the most experienced pilot on this forum, but I think speed brakes are over rated.  The manual in my M20K has two emergency decent procedures.  One is to drop the gear and fly at gear down speeds.  2000 fpm is to be expected.  I'm sure speed breaks would help some...  It just seems the gear is the biggest speed brake.

 

Having said that.  I have speed brakes on my M20K.  They are manual and I use them on those rare occasions when I fail to plan my decent properly and the airport is suddenly a little closer than I care for.   --In these cases, dropping the gear would be to big of a correction.

 

And since I mentioned emergency decent.  4000 fpm in an Acclaim.  Unfortunately, I can't see the cht in the video.

[Jamie]

nobody ever talks about the comfort they can provide by staying up high where it's cool and smooth for as long as possible and then slam dunking it at -2500fpm few miles out. I never find ears to be a problem with experiences passangers who know what to do to continue clearing their ears. Many here fly to achieve maximum mpg, I like speed and comfort.

Yup. According to the tables in my POH, my airplane goes faster the higher I go (TAS). It's also august in the South. I'm staying up where I'm fast and cool as long as I can. Speed brakes aren't correcting a poorly planned descent, they're part of a well planned descent.

[jkenney]

One of the earlier posters mentioned a slam dunk approach into KSNA.    Same thing happens to me every time I fly into Torrance(KTOA) from the northwest.    ATC keeps me at 8000 feet until clear of LAX traffic then descends me rapidly to join the KTOA ILS.    They also give you very tight turns to (1) keep away from heavy practice area traffic south of Long Beach and (2) keep well clear of airliner traffic descending into either Long Beach or John Wayne.     Without speedbrakes it would be a much more significant challenge to descend and keep my speed under control.     In my case they are needed and much appreciated.

[DonMuncy]

Why do you ask? If you are contemplating adding speed brakes, the answer is different than if you are looking at a plane to purchase that has them. I fly a K that has them. If I didn't have them, I probably would not spend the money, as there are other more cost effective ways to spend money. If I was looking for a plane to buy, I would pay some (not sure how much) more to get them.

In my flying, they are never really necessary, but they are often quite helpful. First to stay up out of turbulence as long as possible, and second when ATC slam dunks you.

[AndyFromCB]

On a ferry flight from LPAZ to CYYT I accidentaly pushed the speed brakes button instead of the microphone button. This caused the speed brakes to deploy but was unable to retract due to icing. This nornally is not a major issue except when you are over the North Atlantic against a 40kts headwind with no much fuel reserve. I recalculated my range and found that I will be swiming toward St. John's. To retract the brakes I tried this: I banked the plane to 70 deg and pulled hard on the yoke to create a high G condition for about one turn. To my relief the blades came down and was able to regain normal speed. After this I pulled the speed brakes CB to insure no future deployment. My lesson to this is to pull the speed brakes CB if icing is to be encountered.

 

José 

 

They iced up that quick? I've never used them in icing, but of course, since I got an airplane with TKS, I haven't seen any ice all season long ;-)

[gjkirsch]

I have speed brakes and use them on occasion.  As others have said, when you are high and flying at the speeds of some turboprops, they treat you like a turboprop. When I fly to the east coast from the midwest, I am usually in the flight levels.  I know the arrival procedure they are going to give me that requires a descent to 9000 feet.  I beg beginning 70 miles out and usually by 30 they agree.  So I have to drop 12,000 feet in about 7 minutes. 

 

The other benefit is crossing some turbulance either in flight or descent when you want to slow down a bit and then resume speed. 

 

I have had failures when they won't retract or when just one will and the plane is very controllable. 

 

I am very conscious not to use them in icing conditions

 

I consider them a real benefit and not a crutch for poor flying habits. 

[manu damaschin]

They are very usefull!! Of course you want need them all the time...

[N33GG]

You can add to the list of airports to be ready for a slam/dunk approach:  Houston Hobby and Burbank, CA.  Sure wished I had speed brakes on my BE58TC when I would get handed one of those type approaches.  Not a big deal when you kind of have a clue what is coming and can prepare for it.  When it is a surprise, things can get challenging for the best pilots out there. 

 

Speed brakes are a great tool when used properly.  They should not be considered as only necessary for cleaning up a botched procedure, or a crutch for a poor pilot.

[Earl]

This relates to another thread where a poster made a comment about hating to use speed brakes because it meant he didn't plan his descent well.  My point there and I will repeat it here is that those of us that fly IFR into a busy class B airspace like Atlanta find ourselves all too often being asked to descend several thousand feet over a short distance.  Speed brakes come in very handy.

 

I've had several instances where ATC has asked me at what seems like the last minute while cruising at 10,000 feet to be at or below 6,000 feet by some nearby fix on the STAR.  I could drop the power to slow down, extend my gear, drop like a rock, reach my target altitude, push back in the power and then raise the gear or I can deploy the speed brakes and leave everything alone.  Which would you choose?  I take the latter approach and then when I am at my target altitude all I have to do is dump the speed brakes.  When flying SPIFR adding five steps when two can do the trick is not a good idea.

 

I think these people that go off about the use of speed brakes must spend most of their time flying VFR in class G airspace.  As I mentioned in another thread, my not thinking to use the speed brakes on a slam dunk ILS resulted in me starting down the glideslope at 130 kts versus my usual 90 kts and chasing the needle.  As the CFII sitting next to me watching me struggle said, "Hey dummy, how about using the speed brakes and slow down a little?"  Doh!!

[N201MKTurbo]

I can land a lot shorter with the speed brakes. Turn final about 1/2 mile out 300 feet high power off and speed brakes out. Pitch to maintain speed. I have to plan my turn to final properly, you get a feel for it. I flare over the dirt and touch down on the numbers. My rollout is usually about 300 feet.

[BorealOne]

Funny. I just got in from a short leg flight CYFS CYZF. Flight @ 9000' with a 25 kt tailwind, in the clear over a broken layer of stratus, approximately 2000' thick between 6000' and 4000' with some possible icing over Great Slave Lake, but clear and +0 temps below the layer. ILS 34 into Yellowknife is gated over the lake. 20 nm out, I was cleared to 3000' with the option to plan my own descent to intercept the localizer. Sure, I could have done a nice 500 fpm descent without speedbrakes, but that would have put me in the clag for 2+ minutes during descent. Or, I could punch down through to 3000 at 1500 fpm with the speed brakes to minimize time in the clag. Kind of a no brainer - I used the speed brakes, punched down and into the clear, and cancelled IFR to help out terminal who had a few faster birds queued up behind me.

That's why we have speedbrakes - they give us options. I like options.

[carusoam]

When they come with the plane, you are happy to have and use them for anything like the slam dunk over NYCs class B.

When the clutch wears out and they don't work, you wish they were fixed...

They are the substitute for a slip in the long body Mooney.

They are a cool tool, nothing more.

-a-

[M016576]

"The use of speedbrakes in a large aircraft is primarily used to increase descent rate, something that if done in a Mooney, will pop your eardrums out."

This part is complete malarkey (about the eardrums). If your eardrums get "popped out" it's because you just had a wing break off and your going down rapidly..... Or you're flying with a sinus block (ouch!!!!)

Most guys here have nailed it- good tool. Lean heavily on them to cover mistakes though, and you'll pay the day they no longer work for you. They are less efficient than not using them, as you're disrupting the energy that you've worked to create... But like some have mentioned above, there are times where you're forced into a situation that Speed brakes can help you out of (slam dunks).

If you're VFR, you can always bleed energy by executing an overhead break... Amazing how quick a mooney decelerates during a 3G level turn at 15".... (Note: I don't condone this manuever to those that have not been instructed in it!)

[29-0363]

Speedbrakes are another tool in the toolbox of energy management. Extremely useful when operating in Control zones and you've been left high until the last minute, and they are an aid to engine management on descent (avoidance of shock cooling)..  

 

Their effect is far greater at cruise and descent speeds when the centre of lift is further back, and have some but not a lot of effect if left extended for a go-around or missed approach at lower speeds. 

[carqwik]

No kidding about ATC thinking a Mooney can descend like a t-prop...BTDT.  And after seeing it done in Piper Meridian...I realize why they ask for those 2,000 fpm descents.  Just pull the power back to flight idle in the Meridian and point the nose down....the prop goes flat, the speed stays where it was, and voila, you're coming down awfully fast in the VS...but the airspeed needle doesn't move.  Amazing...  And no worries about engine temps or shock cooling.  Can't do that in a Bravo without busting something....like your ear drums or Vno.  So are speed brakes useful?  You bet...

[RJBrown]

ChristianGodin Flies a J.

That said his original post makes sense. A bit naive and over reaching but understandable.

  I now own a J. I would never spend money to add speed brakes to it. A Js flight environment just does not present the "need" for them. Without experiencing flight in a Rocket/Bravo/Encore and to a smaller extent a Missile/Ovation/Eagle a J pilot just would not understand.

 A Rocket needs speed brakes. I added them to N231NH and would want them on or added to any Rocket I might buy in the future.

The lowest power setting reccomended by Rocket is 45%, there it generates 140HP. That level of power exceeds that available in most conditions in a J and all where I am based. A Rocket can climb 3 times faster in the flight levels than it can decend without speed brakes. At 45% a 500 FPM decent runs a Rocket is up against the redline. There are many situations where this would create problems. Having the time and space for such a decent would be wonderful but you just can't expect or plan for it always. Weather conditions, terrain or center requests can make such a leisurely decent impossible at times. 

 I took a maintainence check flight in a Rocket without speed brakes. It took only 18 minutes to climb to 26,000 feet, without speed brakes the normal decent took 40 minutes. I have come accross Larks enroute to APA in the flight levels to stay above ice and turbulence. Plan me a desent that goes direct and is within the legal flight envelope without speed brakes.