Avionics shop accidentally...

[FeelinFiki]

Hey guys,

Just finishing a complete panel overhaul. We were closing things up and could not figure out why the speed brakes weren't working. They removed my entire vacuum system, not knowing the speed brakes were vacuum driven. Ugh. Thoughts on this? 

 

Thanks!

[Ragsf15e]

Was that on the work order / estimate?!

[FeelinFiki]

Great question. I went back and looked. Nothing on the work order, just the unit and labor costs for each avionic. Nothing about vacuum sys. 

Edited June 30, 2022 by FeelinFiki

[Bunti]

It should not be difficult to put the pump back in and reconnect the speedbrakes only.

[LANCECASPER]

Give them the option - they can hook the vacuum speed brakes back up along with everything that goes with them and get them working that way or they can buy you electric speed brakes or at least cover the labor to install them 

[FeelinFiki]

Good idea  Hopefully it’s an easy/quick fix to restore the vacuum. Thanks all!

[Aerodon]

OK, I have yet to get a clear answer on this.  In a 'normal' system, there is flow through the instruments to the vacuum pump, and the vacuum is regulated by letting in more air through the regulator.  If you block off the instruments, then all the flow goes though a regulator.  Can it cope?  Or should one install a 'bleed valve' with a filter to simulate the instrument flow?  These bleed valves are commonly used on venturis to set the vacuum and not expensive.  Inline filters keep the air clean so you don't mess up the vacuum pump.

And yes, not too difficult to reinstall the vacuum parts for the speedbrakes, and I plan on keeping mine working as long as possible rather than replace.

Vacuum pump, manifold, regulator.

 

Aerodon

 

 

[Shadrach]

On 6/30/2022 at 10:52 PM, Aerodon said:

OK, I have yet to get a clear answer on this.  In a 'normal' system, there is flow through the instruments to the vacuum pump, and the vacuum is regulated by letting in more air through the regulator.  If you block off the instruments, then all the flow goes though a regulator.  Can it cope?  Or should one install a 'bleed valve' with a filter to simulate the instrument flow?  These bleed valves are commonly used on venturis to set the vacuum and not expensive.  Inline filters keep the air clean so you don't mess up the vacuum pump.

And yes, not too difficult to reinstall the vacuum parts for the speedbrakes, and I plan on keeping mine working as long as possible rather than replace.

Vacuum pump, manifold, regulator.

 

Aerodon

 

 

I don't think it's that complicated. The regulator is simply adjusted to provide the spec'd vacuum no matter how many instruments it's driving.  As long as it can operate within specs, everything should be fine.  Should be no problem powering just the speed brakes.

[81X]

14 hours ago, Aerodon said:

OK, I have yet to get a clear answer on this.  In a 'normal' system, there is flow through the instruments to the vacuum pump, and the vacuum is regulated by letting in more air through the regulator.  If you block off the instruments, then all the flow goes though a regulator.  Can it cope?  Or should one install a 'bleed valve' with a filter to simulate the instrument flow?  These bleed valves are commonly used on venturis to set the vacuum and not expensive.  Inline filters keep the air clean so you don't mess up the vacuum pump.

And yes, not too difficult to reinstall the vacuum parts for the speedbrakes, and I plan on keeping mine working as long as possible rather than replace.

Vacuum pump, manifold, regulator.

 

Aerodon

 

 

It can cope, my 231 is set up like this with only the speed brakes hooked up to the vac system.  You may need to adjust the regulator a little though- super fun with the engine running while trying to adjust the regulator on the inside firewall. 
 

While you can put the vacuum pump and its components back on, you can also consider an electrically driven vacuum pump that many have installed as a standby system.  That way, you may be able to get a standby alternator approved on the vacuum pad, at least that’s my plan without spending $8k on electric brakes. 
 

 

[FeelinFiki]

Hey all, thanks for the thoughts on this. I still have the stby vacuum pump in there. The problem they said is that the holes where the vacuum "stuff" used to run are now all threaded through with wires from the panel upgrade. The only option they are saying is to go full electric $$$, or have to mount a vacuum gauge, and a vacuum switch as the stby pump can't just run continuously. If I am understanding correctly, that means having to turn on my pump every time I want to extend or retract. Ugh. Ugh. Not ideal, especially on a go-around, etc. Just a hole in the swiss cheese for error.

 

If they are correct, I might just have to cough up the dough, but am a little hesitant on what the liability should be here. The shop def. screwed up (granted, I am one of the few remaining vacuum driven speed brakes left out there) but still...  not only that, but my current SB were painted the custom color of my plane as well. That would be more time and $. Kind of a mess, not sure what is right for me to pay for. Additionally, I use my Rocket for work, and need it back ASAP, so time is also a consideration.

Edited July 1, 2022 by FeelinFiki

[Aerodon]

29 minutes ago, FeelinFiki said:

Hey all, thanks for the thoughts on this. I still have the stby vacuum pump in there. The problem they said is that the holes where the vacuum "stuff" used to run are now all threaded through with wires from the panel upgrade. The only option they are saying is to go full electric $$$, or have to mount a vacuum gauge, and a vacuum switch as the stby pump can't just run continuously. If I am understanding correctly, that means having to turn on my pump every time I want to extend or retract. Ugh. Ugh. Not ideal, especially on a go-around, etc. Just a hole in the swiss cheese for error.

 

If they are correct, I might just have to cough up the dough, but am a little hesitant on what the liability should be here. The shop def. screwed up (granted, I am one of the few remaining vacuum driven speed brakes left out there) but still...  not only that, but my current SB were painted the custom color of my plane as well. That would be more time and $. Kind of a mess, not sure what is right for me to pay for. Additionally, I use my Rocket for work, and need it back ASAP, so time is also a consideration.

Yes, the vacuum pipe from the rear standby vacuum pump is perfect for threading all the wires through from the back.  If you installed an engine monitor, they may have used the hole through the firewall for that.  That would be a real pain to redo those wires.

I would reinstall the engine vacuum pump, the hose through the firewall (even if it means a new hole), the regulator, the gauge etc.

Note that vacuum is needed to extend the brakes, a spring retracts them.  But I still would not use an electric standby.  And I would not give up the vacuum brakes unless really necessary.

 

Aerodon

 

 

 

 

 

 

 

[Bunti]

 

Tell them to put the pump back in, route an appropriate hose, put a vacuum gauge back in the panel and make it work. It is and was their fault. So they have to fix it.  It cannot be a big problem. This is an hour or two of work.

If the standby vacuum pump is still there and connected to the speed brakes it will be even easier. You just have to connect the engine driven pump in parallel.

The shop has to come up with a solution which does not cost money for you and is acceptable. 

Another option would be getting a quote from another shop to get that fixed and  deduct that amount from you avionics upgrade bill.

 

 

[Mufflerbearing]

There has to be a reasonable delta between your used vacuum SB and new electric brakes.  I would want the weight savings of not having a dedicated vacuum pump system just for one thing that can be swapped out for electrics.  I removed my vacuum system recently and don't miss is for one second.  Sadly, I disposed of my vacuum pumps.  I would have gladly given them to you.

 

[jetdriven]

4 hours ago, 81X said:

It can cope, my 231 is set up like this with only the speed brakes hooked up to the vac system.  You may need to adjust the regulator a little though- super fun with the engine running while trying to adjust the regulator on the inside firewall. 
 

While you can put the vacuum pump and its components back on, you can also consider an electrically driven vacuum pump that many have installed as a standby system.  That way, you may be able to get a standby alternator approved on the vacuum pad, at least that’s my plan without spending $8k on electric brakes. 
 

 

I think the STC specifically states that it has to be an engine driven vacuum pump.  But since the electrical motor drives the vacuum pump in the tail, you should put a standby alternator on that and then you can have your standby alt alt whenever you throw on the switch right? 

[OR75]

The big agenda item in A&P IA renewal seminars these past years has been STC compatibility 

A shop should check that an STC based install is compatible with all previous STCs. 
Most examples they gives are incompatibilities related to airframe mods ( like wing tip tanks , vortex generators, etc… )

 

[M016576]

3 hours ago, FeelinFiki said:

Hey all, thanks for the thoughts on this. I still have the stby vacuum pump in there. The problem they said is that the holes where the vacuum "stuff" used to run are now all threaded through with wires from the panel upgrade. The only option they are saying is to go full electric $$$, or have to mount a vacuum gauge, and a vacuum switch as the stby pump can't just run continuously. If I am understanding correctly, that means having to turn on my pump every time I want to extend or retract. Ugh. Ugh. Not ideal, especially on a go-around, etc. Just a hole in the swiss cheese for error.

 

If they are correct, I might just have to cough up the dough, but am a little hesitant on what the liability should be here. The shop def. screwed up (granted, I am one of the few remaining vacuum driven speed brakes left out there) but still...  not only that, but my current SB were painted the custom color of my plane as well. That would be more time and $. Kind of a mess, not sure what is right for me to pay for. Additionally, I use my Rocket for work, and need it back ASAP, so time is also a consideration.

You could just ask them to remove the speed brakes entirely, as well as the now useless backup vacuum pump, and be thankful for the extra useful load and slightly better CG.  No matter what you choose to do- the shop should be liable for making it right, as they made a massive mistake on this one.

Edited July 1, 2022 by M016576

[FeelinFiki]

So grateful for all the responses. I am chewing this all over. To the above option: I am used to flying an Ovation, and am new to the Rocket, but from what I have seen so far, especially flying into very high density airports (needing to keep speed up on final 150-160+) between the fast let down as well, I feel like I would be fretting shock cooling constantly without the SB>> Is there a way to modify my flight techniques to not need it? Almost seems like a must on her!~

Edited July 2, 2022 by FeelinFiki

[Shadrach]

28 minutes ago, FeelinFiki said:

So grateful for all the responses. I am chewing this all over. To the above option: I am used to flying an Ovation, and am new to the Rocket, but from what I have seen so far, especially flying into very high density airports (needing to keep speed up on final 150-160+) between the fast let down as well, I feel like I would be fretting shock cooling constantly without the SB>> Is there a way to modify my flight techniques to not need it? Almost seems like a must on her!~

I have not flown a rocket. Why would one need to hold 150-160 on final? Are you racing A320s?

[jetdriven]

2 minutes ago, Shadrach said:

I have not flown a rocket. Why would one need to hold 150-160 on final? Are you racing A320s?

Going into IAD two days ago yes, I was, but that’s a rare occurrence.

[Shadrach]

26 minutes ago, jetdriven said:

Going into IAD two days ago yes, I was, but that’s a rare occurrence.

Who won?  Been there done that! Philly put me up against a SWA 737 to intersecting runways. When the controller realized it was going to be a tie, my 150kt .5 mile final to 35 turned into a 150kt left base for 27L

[jetdriven]

In this case I landed it and turned off on the reverse high speed long before these guys behind me touched down. And they even put a guy between us to take off. 

[Guest]

Why all the drama?  All those who have never made a mistake please raise your right hand.

Just have them reinstall the system they removed, correct the log book try and amend the W&B report.

Clarence

[FeelinFiki]

Update for those interested: reinstalled the vacuum system. Was going to just take this opportunity to swap them out for the electric SB's, but apparently (why?) they are a different size, and require some skin work, etc., to change. Not just an even swap. So, vacuum it is. Thanks all for the help and guidance!

[carusoam]

Great follow up FF!

Going all electric definitely comes with challenges….

Speed brakes are nice to have.

Best regards,

-a-