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Upgrade speedbrakes w/ new panel??


khedrei

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4 hours ago, Airways said:

That’s ridiculous money. I would like to know if there is a possibility to hook the backup vacuum pump up with the speedbrakes iso the motor driven one. Not sure if/how this works...

It could be done, as you can probably flip on your backup pump with the master on and the engine off, and your speed brakes will work. I would imagine it would take some vacuum line plumbing, but then would you only turn on your backup pump when you want to pop your speed brakes? I would think the motor running the standby pump is not rated for continuous use for every flight and eats up 12+ lbs. of UL. Then, instead of just putting up your speed brakes, you would have to turn on the backup pump, pop your speed brakes, drop the speed brakes, and turn off the standby pump. Seems like a lot of opportunities for an interruption to the process to cause a problem.

Like @gsxrpilot, I took out all my vacuum instruments and the standby pump but left the engine mounted one connected solely to my speed brakes. They operate the way they always have, I gained 12 lbs. of UL, and if my vacuum pump fails, it affects nothing I need to keep the plane right-side up. Just a thought.

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5 hours ago, Oldguy said:

It could be done, as you can probably flip on your backup pump with the master on and the engine off, and your speed brakes will work. I would imagine it would take some vacuum line plumbing, but then would you only turn on your backup pump when you want to pop your speed brakes? I would think the motor running the standby pump is not rated for continuous use for every flight and eats up 12+ lbs. of UL. Then, instead of just putting up your speed brakes, you would have to turn on the backup pump, pop your speed brakes, drop the speed brakes, and turn off the standby pump. Seems like a lot of opportunities for an interruption to the process to cause a problem.

Like @gsxrpilot, I took out all my vacuum instruments and the standby pump but left the engine mounted one connected solely to my speed brakes. They operate the way they always have, I gained 12 lbs. of UL, and if my vacuum pump fails, it affects nothing I need to keep the plane right-side up. Just a thought.

I have vacuum speed brakes on my 252 and recently removed the failed engine driven vacuum pump and replaced it with a B&C standby alternator. However, during annual the question was raised whether it's allowed to use the vacuum operated speed brakes with only the electric backup vacuum pump driving it. Precise Flight said "no", it's not allowed - so my speed brakes are currently placarded INOP. Perhaps in the future I'll replace the speed brakes with the electric version but it's not too much of a priority.

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One of the advantages of the vacuum speedbrakes is that the single actuator in the belly with cables to the speedbrake panels means that an asymmetric stuck speedbrake is very unlikely. I seem to recall a few stories about that from the electric ones.

The disadvantage is that the colder it gets, the more likely they will both stay partly extended once you put them out. I avoid using them in the winter here in Canada.

it would be nice if somebody could STC an electric actuator to replace the rubber bellows in the vacuum actuator. That would allow removal of the engine driven pump (assuming no vacuum gyros) and no more sticky speedbrakes in cold weather.

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I have vacuum speed brakes on my 252 and recently removed the failed engine driven vacuum pump and replaced it with a B&C standby alternator. However, during annual the question was raised whether it's allowed to use the vacuum operated speed brakes with only the electric backup vacuum pump driving it. Precise Flight said "no", it's not allowed - so my speed brakes are currently placarded INOP. Perhaps in the future I'll replace the speed brakes with the electric version but it's not too much of a priority.

How would the speed brakes know where the vacuum was coming from? Hopefully they didn’t disable your system in any way.
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1 minute ago, larryb said:

How would the speed brakes know where the vacuum was coming from? Hopefully they didn’t disable your system in any way.

Exactly. And they're not required equipment. I probably wouldn't have asked, and just hooked them up. 

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10 hours ago, ArtVandelay said:


That hasn’t been my experience, but they do need to be lubed on occasion.

Yes with Aeroshell 22 only. People make the mistake of spraying Tri-Flo which removes the Aeroshell 22 and there's no lube. Then once they fail they send them in for an overhaul.

Mine were a little noisy and one was a little slower than the other. I took the cartridge out, lubricated the worm and worm gear properly in each, and they both are much quieter and operate the same now. They should be lubed every year at annual.

1162982156_ScreenShot2020-07-01at9_23_52AM.thumb.png.83914ff12bfeca9a93722a50c6fc682e.png

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12 hours ago, squeaky.stow said:

it would be nice if somebody could STC an electric actuator to replace the rubber bellows in the vacuum actuator. That would allow removal of the engine driven pump (assuming no vacuum gyros) and no more sticky speedbrakes in cold weather.

That would also remove the problem of having the bellows give up and trying to find a replacement part, which I believe is/was made by Brittain.

Who was it that came up with the electric step retraction replacement for the vacuum ones? Here is another potential opportunity covering more than just Mooneys!

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3 hours ago, gsxrpilot said:

Exactly. And they're not required equipment. I probably wouldn't have asked, and just hooked them up. 

Several A&P's from Savvy including @kortopates weighed in. The system is still functional but placarded as a CYA, I used Advanced Aircraft (MSC) in Troutdale for the annual where this came up.

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I'm late to this party, but I also left my engine driven vacuum pump in solely to power my vacuum speedbrakes. Removed standby vac.  Lost almost 50 lbs when I did my panel: the entire KFC200 system is 37 lbs alone!

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I also just had the standby vacuum system removed but kept the engine driven pump just for the speedbrakes.  My speedbrakes have always worked well but they are a little slow to fully deploy at idle speed but I only use them in some descent situations which is not at engine idle speed.  (I also use  them when I want to show a rider how cool they are...they really are cool!)

I suspect there are going to be a lot of standby vacuum systems for sale on ebay over the next few years and going for a bargain price!

+8,000 for not switching vacuum to electric speedbrakes

 

 

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On 7/1/2020 at 10:50 AM, Florg said:

Several A&P's from Savvy including @kortopates weighed in. The system is still functional but placarded as a CYA, I used Advanced Aircraft (MSC) in Troutdale for the annual where this came up.

Yes, I am sorry the way it turned out. I was really arguing that since it wasn't required equipment it shouldn't matter and the speed brake installation wasn't at all modified. But in the end Precise Flight was saying they never certified it off the standby alone and the installation is no longer in accordance with the STC (which is the real legal issue). But IMO its still shouldn't be an issue since the Precise system was certified to get its vacuum off the vacuum manifold, whether dual manifold with 2 vacuum sources such as the 252 or single manifold with only 1 vacuum source like a 231, and it shouldn't really matter if an installation went from dual sources to a single source with no change in plumbing. 

The other issue is that I don't think Precise really has any remaining staff that is still knowledgeable about the old vacuum brakes.   

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15 minutes ago, larryb said:

IMO one should not ask a question like this when it is likely to get an answer you don’t like. Why did the MSC need to make an issue out of this?

In sales, which is my profession, you never ask a question that you don't already know the answer to.

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I thought I should let people know my outcome since I started this thread and it seems to have been revived. 

I paid 5k USD for the speedbrake kit at Osh prices. My mechanic installed them and I think he charged about 25 hours or so. So that's about 2700 CAD. Avionics guy charged another 4 hours to do the final wiring.

Was it worth it? The functionality is obviously the same. They look a bit cooler when deployed (nice shiny anodized metal instead of painted) and are faster to retract. Probably the same speed to deploy. Having spent what I did on the panel I really do like knowing that everything is new front to back. It's a good feeling. Looking back on it, there was minimal wiring to the panel and leaving the vacuum system would have been easy enough and could have been removed later after running the speedbrakes to the end of their life. It just would have been annoying to have them fail after doing all this work and who knows if I would have had money set aside to replace when it came time. All in all I dont regret it. 

I am curious how others had the conversion done though. The new plate they gave me, my mechanic simply surface mounted it. He said the plate was needed because the old hole didnt line up with the new one. He did a nice job and painted everything but I'm wondering if there was a cleaner way to do it. I know the airflow has already separated from the wing at that point so there is little if any drag added, but it would have been cool if they could have been flush like the old ones. I'll post a picture tomorrow. I'm curious what others did. 

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1 hour ago, larryb said:

Just remember to lubricate them every year or ask your mechanic to do it. That lubrication is generally not done automatically at annual unless you ask for it.

From a regulation standpoint, the lubrication should be done, since it’s on the ICA for the speed brakes. 

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From a regulation standpoint, the lubrication should be done, since it’s on the ICA for the speed brakes. 

I agree it should be. My MSC doesn’t do it. I posted it here a year or so ago and for many others it does not seem to be done regularly either. It appears to be something you have to ask for.
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40 minutes ago, khedrei said:

Here is pics of my upgraded speedbrakes. Curious if anyone else did the electric conversion and were able to get away with a cleaner install than this?

That looks really good. I'm doing my conversion at annual in September.

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