Speed Brake Problem

[Mcxmike]

Two days ago, the left speedbrake deployed about 1/3 of the way up and started “fluttering”. But it retracted OK. Then it did the same thing but after a couple minutes, would not deploy at all. Has anyone experienced this or know what the problem is?  I drive a rocket conversion and sort of rely on them .

[carusoam]

Electric or vacuum driven?

Electric has clutches that wear.  

Clutch replacement is based on deployment, Not so much flight hours, so it is hard to expect when this would be needed.

Fortunately, uneven deployment in an ovation is only slightly distracting...

Best regards,

-a-

[ionel]

Quote: Mcxmike

Two days ago, the left speedbrake deployed about 1/3 of the way up and started “fluttering”. But it retracted OK. Then it did the same thing but after a couple minutes, would not deploy at all. Has anyone experienced this or know what the problem is?  I drive a rocket conversion and sort of rely on them .

[David Mazer]

I had a problem with my Rocket's speed brakes from icing.  Wouldn't go down for a while.  At the next annual (or maybe the one after that) we found that all the cables on both sides had stretched and needed to be replaced.  Basically the entire rigging we re-done.  No problems since and the IA didn't think the icing was the cause especially since it was on both sides.  My speed brakes won't work unless the engine is on or the master and the backup vacuum is running when the engine is off.  I have been told but don't really know that they are electric and vacuum operated.

[Bennett]

The older speedbrakes were vacuum, while the newer units are all electric. I've had both kinds. the 231/261 were vacuum, while my 201 speedbrakes are electric.

[fantom]

Electric ones seem less problem prone.

[Bennett]

I concur with fantom. The vacuum system sucks (pun intended). It is hard on the vacuum system, and is overly complicated. The only asymmetric deployment I ever had was with the vacuum system (in ice - I was slow in retracting them, and one only retracted part way until I was out of the ice - I had deployed then to get down to warmer air as quickly as possible- no problem in controlling the aircraft.)

[BorealOne]

Had the same issue with my electric Precise Flight speedbrakes. LHS became erratic - sometimes went up, sometimes went down so I called it U/S, pulled the breaker and had them both removed and sent to Precise Flight for an overhaul. Pretty quick turnaround - about a week including shipping to/from Calgary.

[AndyFromCB]

Vacuum system does not have any clutches and a asymetric deployment is not possible because there is a single drum pulling both cables so unless a cable brakes both will pop up. Now when it comes to retracting, that's a different story. Sometimes you just need to slow down. What I love about my vacuum system on my 1990 Bravo is that short of the drum/below going, my total overhaul cost was 30 bucks for some new springs and a few hours of my own labor with a fishing line to replace the springs.

How is it overly complicated. One valve, one drum, two cables? 

[AndyFromCB]

Quote: Mazerbase

I had a problem with my Rocket's speed brakes from icing.  Wouldn't go down for a while.  At the next annual (or maybe the one after that) we found that all the cables on both sides had stretched and needed to be replaced.  Basically the entire rigging we re-done.  No problems since and the IA didn't think the icing was the cause especially since it was on both sides.  My speed brakes won't work unless the engine is on or the master and the backup vacuum is running when the engine is off.  I have been told but don't really know that they are electric and vacuum operated.

[Mcxmike]

Thanks to all comments and suggestions. I spoke with Precise Flight (the manufacturer) and they suggested I send them back for an inspection. They've worked flawlessly for over 16 years and gotten me out of quite a few tight spots so I think I'll do that. S/F Mike

[carusoam]

Thanks Astel, I have updated my statement for improved accuracy.

-a-

[rbridges]

I didn't realize so many people had speed brakes.  Were they standard issue on the newer planes?

[Hank]

Rob--

They are mostly on turbo birds that need to come down a long ways. Helpful on slam-dunk approaches and when flying out west, clearing terrain and dropping into the valley to land. Some E, F & J planes also have them. You and I don't need them, although my last flight they'd have been nice--ATC wouldn't accept my IFR cancellation due to an airliner inbound from the south to land on 30, and I was flying 120 several miles to the north to come around and land on 26 at our uncontrolled field. Kept me at 4000 until just a mile or two out, there's just no coming down to pattern of 1600 that fast without them, and maybe not even with them. One 360 a couple miles north of the field, then a crossover and I had it.

Look at the bright side--it's one less system to maintain.

[ionel]

Quote: Hank

Rob--

They are mostly on turbo birds that need to come down a long ways. Helpful on slam-dunk approaches and when flying out west, clearing terrain and dropping into the valley to land. Some E, F & J planes also have them. You and I don't need them, although my last flight they'd have been nice--ATC wouldn't accept my IFR cancellation due to an airliner inbound from the south to land on 30, and I was flying 120 several miles to the north to come around and land on 26 at our uncontrolled field. Kept me at 4000 until just a mile or two out, there's just no coming down to pattern of 1600 that fast without them, and maybe not even with them. One 360 a couple miles north of the field, then a crossover and I had it.

Look at the bright side--it's one less system to maintain.