Speed Brake Overhaul

[N81FM]

Hello, 
My 1999 Mooney Ovation came from factory with speedbrakes. I saw in the "Mooney M20R Service and Maintenance Manual" that an overhaul was recommended evry 1000 hours. During a pre-purchase inspection, the workshop tells me that the overhaul of speedbrakes is mandatory every 1000 hours.
What is the reality? Do any of you have an official document indicating the obligation of this overhaul at every 1000 hours ?
Thank you all

[ArtVandelay]

Are you using your plane for commercial purposes? If not, it’s not mandatory. No manufacturer can dictate maintenance to part 91 here in the USA, not engines (TBO), not propellers, etc…are you in Canada…they have different laws?

[Guest]

Only Chapter 4 items,  or items driven by an AD are mandatory.

[Sue Bon]

1 hour ago, ArtVandelay said:

are you in Canada

LFPN is Paris. N reg would be FAA rules.

[LANCECASPER]

2 hours ago, N81FM said:

Hello, 
My 1999 Mooney Ovation came from factory with speedbrakes. I saw in the "Mooney M20R Service and Maintenance Manual" that an overhaul was recommended evry 1000 hours. During a pre-purchase inspection, the workshop tells me that the overhaul of speedbrakes is mandatory every 1000 hours.
What is the reality? Do any of you have an official document indicating the obligation of this overhaul at every 1000 hours ?
Thank you all

The Instructions for Continued Airworthiness for the Speed Brakes says that the cartridge should be taken out each year and that the worm gear mechanism should be lubricated with Aeroshell 22 (do not use spray lubricant, as this removes the Aeroshell 22). By doing this you can keep them going many years without the need for overhaul. Especially if you have TKS this should be done regularly as the TKS fluid breaks down the Aeroshell 22 and leaves it without lubrication. 

[Deb]

4 hours ago, ArtVandelay said:

Are you using your plane for commercial purposes? If not, it’s not mandatory. No manufacturer can dictate maintenance to part 91 here in the USA, not engines (TBO), not propellers, etc…are you in Canada…they have different laws?

 

3 hours ago, M20Doc said:

Only Chapter 4 items,  or items driven by an AD are mandatory.

Interestingly, the Precise Flight Speedbrake 2000 Installation Manual https://drive.google.com/drive/mobile/folders/1zNzigTBKlcwuP15YLIlblPUmIxntvRkR/1YL2qbshoCTjBBmTnsjagvjaTAO0rsEvb/1UT6ozCB-VW5IsapNzysKtLfz3c5rmLNV?usp=sharing&sort=13&direction=a has a Section 4 titled “Instructions for Continued Airworthiness “ on page 23 and 24 (specifically items 4.6 and 4.7):

Here’s page 25 with the maintenance schedule:     

[N81FM]

Thanks for your feedback.

i'm not using the plane for commercial purposes.

Your comment "Only Chapter 4 items,  or items driven by an AD are mandatory" is interesting because this is exactly the point the guy who did the inspection mentionned.

he says Speedbrakes overhaul every 1000 hours is part of this chapter 4 !

How can we check that ?

[Marc_B]

@N81FM I'd recommend you contact Precise Flight directly.  They were super responsive and helpful when I had questions and needed AFMS material for my Mooney.

https://preciseflight.com/contact/

They also have documents available for download when you go to Support > documents.

[LANCECASPER]

2 hours ago, N81FM said:

Thanks for your feedback.

i'm not using the plane for commercial purposes.

Your comment "Only Chapter 4 items,  or items driven by an AD are mandatory" is interesting because this is exactly the point the guy who did the inspection mentionned.

he says Speedbrakes overhaul every 1000 hours is part of this chapter 4 !

How can we check that ?

Look at the post right above yours. It shows that they recommend Clutch Lubrication and Spring Replacement at 1000 hours and Drive Assembly Replacement  at 5000 hours.

[N81FM]

I think this is more than a recommendation, that must to be done. Correct ?

[Marc_B]

37 minutes ago, N81FM said:

I think this is more than a recommendation, that must to be done. Correct ?

Those recommendations are Instructions for Continued Airworthiness (ICA).  So the answer is if you need to comply with ICA instructions in your country.  In the US for part 91 flight the answer would be not mandatory but recommended.  But for commercial flight it would be mandatory.

[carusoam]

One thing for sure…

The clutches do wear out…

When they do, gravity helps close them up…

uneven deployment of one brake instead of two… is a non-issue.

Actual hours on the brakes are hard to measure… mine get tested every pre-flight.

Somewhere around 1500hrs both were sent in for new clutches…. Expensive, Quick turn around.

 

PP thoughts only, not a mechanic…

Best regards,

-a-

[PT20J]

I don't know about other countries, but in the USA is works like this:

The only time that ICA recommendations are mandatory for Part 91 is if they are specifically listed as Airworthiness Limitations, and if so, those limitations will have a FAA approval since only the FAA can set airworthiness requirements.

Look carefully at the document that @Deb posted which is an excerpt from the PreciseFlight manual. The FAA notice in the box in Section 4.6 is boilerplate. The important information is in the Note below. This could have been better worded to make it clear that there are no limitations whatsoever, but I think the intent is clear. Many ICA documents just say NONE.

Here is a better example from a Garmin maintenance manual

[M20F]

3 hours ago, Marc_B said:

@N81FM I'd recommend you contact Precise Flight directly.  They were super responsive and helpful when I had questions and needed AFMS material for my Mooney.

https://preciseflight.com/contact/

They also have documents available for download when you go to Support > documents.

A lot of conflicting information on this thread. This is probably where I would head.  

[ArtVandelay]

The problem is they have to set maintenance schedules for a worst case scenario.
So
A. Plane is tied down outside and makes lots of short flights and brakes are used on every flight. Remember the brakes are exposed to rain.
B. Plane is hangared and only uses them on occasion.

There’s no way those 2 scenarios should have the same maintenance schedule.

[Guest]

7 hours ago, N81FM said:

Thanks for your feedback.

i'm not using the plane for commercial purposes.

Your comment "Only Chapter 4 items,  or items driven by an AD are mandatory" is interesting because this is exactly the point the guy who did the inspection mentionned.

he says Speedbrakes overhaul every 1000 hours is part of this chapter 4 !

How can we check that ?

From the Ovation maintenance manual, here is chapter 4 mandatory item and chapter 5 recommended items.  Sorry that the pages aren’t in the correct order.  The second one here is chapter 4.

[Guest]

2 hours ago, M20F said:

A lot of conflicting information on this thread. This is probably where I would head.  

I’m certainly no expert, but my understanding has always been that the airframe manufacturer’s chapter 4 takes precedence over everything.  So Precise Flight can have their recommended service, but Mooney Maintenance Manual chapter 4 over rides Precise Flight because Mooney installed the system as part of the certification.  

Now if you installed Precise Flight speed brake via an STC and the STC contains an ICA, you must follow it.

[Pinecone]

1 hour ago, ArtVandelay said:

The problem is they have to set maintenance schedules for a worst case scenario.
So
A. Plane is tied down outside and makes lots of short flights and brakes are used on every flight. Remember the brakes are exposed to rain.
B. Plane is hangared and only uses them on occasion.

There’s no way those 2 scenarios should have the same maintenance schedule.

Then write a schedule that handles those two and many other in between circumstances, and gets the job done properly

[Schllc]

I’ve seen planes logbooks where they have been sent in repeatedly for repairs and I’ve seen 16 year old planes that never had them touched.
1000 hours and 5000 hours seems awfully arbitrary. 
I wouldn’t send for service until required for function. 
They aren’t really needed in a Mooney anyway so why spend 1500+ unless they need service. 

[PT20J]

2 hours ago, M20Doc said:

I’m certainly no expert, but my understanding has always been that the airframe manufacturer’s chapter 4 takes precedence over everything.  So Precise Flight can have their recommended service, but Mooney Maintenance Manual chapter 4 over rides Precise Flight because Mooney installed the system as part of the certification.  

Now if you installed Precise Flight speed brake via an STC and the STC contains an ICA, you must follow it.

That's the point. Mooney has always, to my knowledge, installed the speed brakes under STC. The factory once explained to me that it was way less paperwork to install them under STC using their repair station certificate than to add them to the type certificate and install them under their production certificate.

Skip

[PT20J]

The overhaul is pricey. As they are not required for flight, the smart thing to do is to lubricate them frequently and repair them on condition. Part of the problem with them is that they are exposed to the elements and some of the components (microswitches and motor) are not hermetically sealed. It is possible to lube them without removing them.

Skip

[N201MKTurbo]

If your spring breaks, you will never drill a new hole in it. But a Harbor Freight heavy duty hole punch will pop a new screw hole in it with no effort.

[LANCECASPER]

12 hours ago, PT20J said:

The overhaul is pricey. As they are not required for flight, the smart thing to do is to lubricate them frequently and repair them on condition. Part of the problem with them is that they are exposed to the elements and some of the components (microswitches and motor) are not hermetically sealed. It is possible to lube them without removing them.

Skip

I was looking through the paperwork from the previous owner of an airplane that I used to own. Back around 2000 they worked on one of his speed brakes and replaced quite a few parts - in all it was just over $200. The same service now would be at least $1500. I think they figured out that people will pay it. 

[ilovecornfields]

Interesting. I just looked at the Precise Flight website to try to get the document @Debposted and saw that they advertise them as being good in turbulence. Has anyone tired this? I usually just slow to maneuvering speed and put the gear down if it’s really bad but I’ve never tried using speed brakes.

[201Mooniac]

23 minutes ago, ilovecornfields said:

Interesting. I just looked at the Precise Flight website to try to get the document @Debposted and saw that they advertise them as being good in turbulence. Has anyone tired this? I usually just slow to maneuvering speed and put the gear down if it’s really bad but I’ve never tried using speed brakes.

I've used them several times when encountering unexpected turbulence.  It is a quick way to slow down to Va and they do seem to help with the ride.