speed brakes

[jetdriven]

Lots of times an overhaul is an inspection and a new tag for 1200$.   What ever happened to IRAN?  

[jhbehrens]

I have heard its good practice to occasionally pull the speedbrake CB - on the ground obviously - with the breaks up. They will fall down into the wing with a bang and this will cycle the cog so you dont always use the same spot on it.

Jorgen

[Jvancecpa]

Quote: allsmiles

This same thing happened to me a few weeks ago. I called precise flight and spoke to Dave. He handles sb tech support. He gave me some pointers as to how to try and diagnose the problem before removing them. It happens to be a simple fix but I plan to send them both in for an oh anyway. You may want to call them. Dave was very helpful. You can pull them out yourself and send them in. It would be a good idea to cover the opening with a plate if you plan to fly though!

[fantom]

Quote: jetdriven

Lots of times an overhaul is an inspection and a new tag for 1200$.   What ever happened to IRAN?  

[PTK]

Quote: jetdriven

Lots of times an overhaul is an inspection and a new tag for 1200$.   What ever happened to IRAN?  

[Shadrach]

Quote: allsmiles

I guess in the case of speed brakes if they work properly you wouldn't just remove and IRAN or oh for that matter. They are not like say a recurring mandatory item like mags for example. Speed brakes either pop out or they don't. If they don't then they have to be looked at. In other words to just remove for the sake of IRAN them is probably unecessary.

[jlunseth]

LThere was an earlier thread on speedbrakes and Don Kaye went out and did some tests of the speedbrakes for landing.  He explained his results and how he uses the brakes in this thread:

http://www.mooneyspace.com/index.cfm?mainaction=posts&forumid=1&threadid=1360

Personally, I do not deploy them often in my 231.  I prefer to make my descent without the brakes whenever possible, don't want to burn up that precious energy created during the climb to altitude.  They are not necessary when given enough time and distance.  But that is the problem, getting down from FL210 can take 35-40 minutes at 500 fpm, and with a big time tailwind that can be 125 nm.  Sometimes ATC won't let you have that much space and/or time.  So generally, I use the brakes only if ATC wants me to expedite descent for some important reason, or if they have left me high on the approach and I need to do something other than just pulling back the power to get my speed down to Vle.  I have not ever used them during a landing but should give it a try sometime.

There was the one time though when we had to do an emergency descent from 19K, with a 75 knot tailwind, to an airport only 20 miles a way.  I was sure glad to have the "crutch" to slow the plane and stay safely below Vne.

I have posted this before: I understand from Willmar that the later model Mooneys, particularly the Acclaim and Acclaim S, really need the brakes.  The airframe is so slippery it will readily exceed Vne if you tip the nose over to start a descent from the Flight Levels.  Don't have an Acclaim myself, so really can't say.   

[Jvancecpa]

Dave at Precise Flight suggested swapping the brakes to see if it was the brake motor.  After reversing the brakes, the left side brake still did not deploy.  Therefore, he felt like it was probably something in the Logic Controller.  So....remove the brake boxes and controller and ship back to Precise Flight.

So now we will see what happens next.  Having plates overnighted to cover holes in wings so plane will be airworthy.

JVanceCPA

[ghovey]

THe folks at Precise Flight are top notch. I had my speed brakes removed and overhauled at 1000 hrs.  Then about 175 hours later we had a problem with one actuating before the other. Removed and sent back last month and covered under their warranty they fixed it and they now work great.  

[Ned Gravel]

Quote: jetdriven

Parker leaves it there as the annual takes 12 months to do.  Then it is due again.  He does get to test fly it occasionally.  I think Don painted the outline of the 252 on the floor where his is parked 

:)))

[231Pilot]

I am currently flying my third Mooney, and it is the first of the 3 to have speed brakes.  Are they necessary?  Probably not.  Are they a good tool to use for quick descents?  Absolutely.  To say that relying on speed brakes makes your aircraft beyond your capabilities, is like saying that using your GPS makes you a lesser pilot than using only your VOR or ADF, or using your WSI weather makes you a lesser pilot than one who relies only on Flightwatch and on ground weather briefings.  I think that proper use of all the tools at hand (autopilots, speed brakes, datalink weather, gps, etc) help us all to be better pilots as long as we practice and remain proficient flying our aircraft without them.

[aviatoreb]

Quote: jlunseth

LThere was an earlier thread on speedbrakes and Don Kaye went out and did some tests of the speedbrakes for landing.  He explained his results and how he uses the brakes in this thread:

http://www.mooneyspace.com/index.cfm?mainaction=posts&forumid=1&threadid=1360

Personally, I do not deploy them often in my 231.  I prefer to make my descent without the brakes whenever possible, don't want to burn up that precious energy created during the climb to altitude.  They are not necessary when given enough time and distance.  But that is the problem, getting down from FL210 can take 35-40 minutes at 500 fpm, and with a big time tailwind that can be 125 nm.  Sometimes ATC won't let you have that much space and/or time.  So generally, I use the brakes only if ATC wants me to expedite descent for some important reason, or if they have left me high on the approach and I need to do something other than just pulling back the power to get my speed down to Vle.  I have not ever used them during a landing but should give it a try sometime.

There was the one time though when we had to do an emergency descent from 19K, with a 75 knot tailwind, to an airport only 20 miles a way.  I was sure glad to have the "crutch" to slow the plane and stay safely below Vne.

I have posted this before: I understand from Willmar that the later model Mooneys, particularly the Acclaim and Acclaim S, really need the brakes.  The airframe is so slippery it will readily exceed Vne if you tip the nose over to start a descent from the Flight Levels.  Don't have an Acclaim myself, so really can't say.   

[carqwik]

The speed brakes are very useful, especially for the turbo models up high, where I've found ATC expects descents closer to what a turboprop can deliver...and that's sometimes 1000fpm or greater and if IFR and one gets a crossing restriction late.  It's impossible to do that without throwing out the "boards" and not going past Vno or even Vne if you're trying to keep the engine toasty.

Of course, they can be a good crutch as well for the times one needs to slow down quickly for traffic in the pattern....

But of course, the best part is throwing them out after landing (even though they have limited utility then)...just looks cool.

[jlunseth]

I prefer long shallow descents for two reasons.  One is that you pick up quite a bit of speed over a long distance.  Probably around 30 knots.  This speed advantage does deteriorate as you get lower, and back down in the area where indicated and true airspeed are closer together.  So you would prefer not to start a descent from FL210 for example, 125 nm out, and then find yourself at 60 nm out and 4,000 feet having to do that last 60 nm at quite a bit slower airspeed.  That is the "art" part of a descent.  You want to look at the winds aloft at lower altitudes and make sure, if you have a very good wind at FL210, that the winds don't fall off rapidly in the lower altitudes.

I have found myself averaging 240 GS in the cruise and then seeing 270 GS for a starting descent speed without the indicated airspeed leaving the green arc.

The other is that I have passengers who regularly fly with me who have ear clearing problems.  I don't, so I can do 2-3,000 fpm in a pinch and not have a problem.  But passengers who do have clearing issues appreciate 500 fpm, rather than "slamdown" descent rates.   If forced to do a slamdown, speedbrakes are your friend. 

[AndyFromCB]

At the risk of once again being called names, let me add two more cents. The are also wonderful safety tool in the mountains like Jackson Hole and/or Granby allowing you to stay up high for as long as possible. I wouldn't fly to either of the locations without them. The actually allow me to be more efficients and burn less fuel by not being forced to do 30 minutes circling descents from FL200 down to 6000 in Jackson Hole. Basically, I fly over the valley, descent to FL180, cancel my IFR, pop out the breaks and down we go. On the ground in 5 minutes. This way I'm always within gliding range of a flat valley. You couldn't pay me enough to fly there in a single in IMC. Last mooney that attempted that is still in pieces on Gannett Peak. But I'm sure some of you here will find multitude of reasons why a turbo is actually a disatvantage in the mountains, really, just a crutch for amateurs instead of the pros who use the mountain waves to their advantage.

[jlunseth]

I have experienced the same at Kalispell (KGPI).  Came in direct, the airport is not far from the mountains, and we were basically several thousand feet up on downwind. Brakes were my friend. 

Like anything else in the aircraft, even my ADF, they are a tool.  Some tools you use every time, some tools not so much, but ifyou have the tool and have not learned how to use it you must have left your "license to learn" in your other pants pocket.

[29-0363]

I experienced assymetric speed brake operation on my first Ovation and did the investigation as to why.  Providing the microswitches are OK, the circuitry should prevent one operating without the other, so it was a mechanical issue I was looking for.  The S/B was disassembled and part of the drive mechanism consists of split bronze bushes with a flat wound spring (similar to the back spring in the U/C manual extension).  

This spring is designed to allow rotation in one direction and free-wheel with reverse rotation.  The failure was caused by wear in the split bushes which moved apart when the spring was driving the S/B out, the spring wound itself into the gap and the mechanism failed.

 

[Jvancecpa]

Well, I realized I never finished the odyssey of the inop speed brake.  Sent them back to Precise Flight.  Spoke with them personally, very nice, and found out that the motor in the logic controller and the left brake were "fried".  Precise Flight fixed the problem and advised me to exercise them several times to see if there might be a wiring problem.  They said they would warrant them after this fix but only fix them one more time if it is a wiring problem within the aircraft.  I have flown the plane several times testing the brakes a lot and everything seems fine now.  Hopefully, just one of those gremlins that happened.

Anyway, up and going again.

Thanks.