TKS W&B Question

[V1VRV2]

I was looking through my POH and the TKS supplement. I can’t find the arm for the TKS tank to calculate an accurate W&B. I was just going to use the rear seat arm as the tank is located under the seat but was looking for an official number.

Just kidding. I found it! 70.7 in.

Does the weight of the TKS fluid reduce the rear seat useful load of 340#?

[Mcstealth]

I can not see how the rear seat weight numbers would be affected as the W&B for the bird  is calculated with full TKS tanks.

My opinion only

 

 

[StevenL757]

4 hours ago, V1VRV2 said:

I was looking through my POH and the TKS supplement. I can’t find the arm for the TKS tank to calculate an accurate W&B. I was just going to use the rear seat arm as the tank is located under the seat but was looking for an official number.

Just kidding. I found it! 70.7 in.

Does the weight of the TKS fluid reduce the rear seat useful load of 340#?

The weight of the fluid does NOT reduce the weight limit you can impose on any seat.  Full TKS only reduces your overall useful load.

[hypertech]

1 hour ago, Mcstealth said:

I can not see how the rear seat weight numbers would be affected as the W&B for the bird  is calculated with full TKS tanks.

My opinion only

 

 

I can't find a statement in my books one way or the other.  Where is that written down?

[V1VRV2]

Nowhere in my POH does it show the quantity of fluid in the tank during weighing. It does give the empty weights before and after install of the TKS and stby altenator. 88lbs for both. That weight would appear to be an empty TKS tank. I have seen posts here of others W&B for TKS and the fluid quantities vary.

[Mcstealth]

2 hours ago, hypertech said:

I can't find a statement in my books one way or the other.  Where is that written down?

That W&B is calculated with full tanks? That is certainly how Mooneys with both FIKI and non are calculated. 

[CAV Ice]

On a FIKI Mooney the installation weight and balance for the system is calculated with no fluid. (Weight: 51.1 lbs, Arm: 80.1, Moment: 4093.1).  This is used for calculating your new empty weight.  The numers for your everyday weight and balance (fluid weight) comes from section 6 page 31 of your 08100-FMS Flight Manual Supplement.

On a No-hazard Mooney the installation weight and balance for the system is also calculated with no fluid.  (Weight: 36.7, Arm: 79.6, Moment: 2921.3).  The numbers for your everyday weight and balance (fluid weight) comes from Section 6 page 13 of your 04600FMS Flight Manual Supplement. 

[carusoam]

Way to go CAV Ice!

Thanks for filling in the TKS details!

Best regards,

-a-

[Mcstealth]

On 11/10/2020 at 1:42 PM, Mcstealth said:

That W&B is calculated with full tanks? That is certainly how Mooneys with both FIKI and non are calculated. 

Edit, correction. 

I am sorry for having UL in my brain while responding to this w&B thread.  I completely blew that. 

[Little Dipper]

On 11/10/2020 at 4:05 PM, CAV Ice said:

On a FIKI Mooney the installation weight and balance for the system is calculated with no fluid. (Weight: 51.1 lbs, Arm: 80.1, Moment: 4093.1).  This is used for calculating your new empty weight.  The numers for your everyday weight and balance (fluid weight) comes from section 6 page 31 of your 08100-FMS Flight Manual Supplement.

On a No-hazard Mooney the installation weight and balance for the system is also calculated with no fluid.  (Weight: 36.7, Arm: 79.6, Moment: 2921.3).  The numbers for your everyday weight and balance (fluid weight) comes from Section 6 page 13 of your 04600FMS Flight Manual Supplement. 

My FIKI was installed by the Mooney factory and the W&B sheet in my POH states that the weight is calculated with "Full Fluid"

Norm

N995K

 

 

[hypertech]

Mine was also installed at the factory and it just doesn't say.  All I have is an original empty weight.  I'll look again next time I'm out at the plane. 

[PaulM]

Mine was also factory installed and weighed, but I don't remember a notation on the fluid status. 

I know when I added up the hardware weights of the AC and TKS in the POH that the delta was not just the hardware. 

I'll check the POH in the plane the next time I'm up there and re-run the numbers. 

[PhateX1337]

Reviving this one - just bought a Bravo with FIKI and see it's in the W&B from the factory as 95 lbs at 74.6 ARM - seems like some sort of combined weight of system & tank weight & moment? Anyone else seeing this? It's never been updated since then - just W&B updated by addition/subtraction for various updates since then.

Seems like I'm paying a weight penalty for an "average" amount of fluid loaded at all times? @CAV Ice any thoughts?

[carusoam]

@PhateX1337,

You should have all the details for WnB calculations available with the STC for the system….

It has two parts to it…

• Hardware
• TKS fluid

The hardware doesn’t change unless converting a non-Fiki system to Fiki…

But the fluid tanks change weight as they get filled or emptied for each flight.  Some MSers use a WnB calculator app  to know exactly where their WnB is at the touch of a screen….

 

There are some basic maintenance items to become familiarized with…as TKS fluid tries to dry out in the system in the summer months…

And some things to look for during pre-flight…. Wild panels trying to escape captivity… 

Congrats on the Bravo acquisition!

A great conversation to have during transition training….

PP thoughts only, not a CFI….

Best regards,

-a-

[CAV Ice]

@PhateX1337

FIKI Mooney installation (no fluid):

Weight: 51.1 lbs

Arm: 80.1

Moment: 4093.1

Fluid weight and balance information is located in your Flight Manual Supplement Section 6.

Although TKS is not typically required in the warmer months we still recommend running the system AT LEAST once per month (ideally twice).  This prevents air/water from collecting in the system.  Common things we've seen with inactive systems include main pump corrosion, filter corrosion, windshield pump failure and panels not fully wetting out.  Recently had a system that wasn't run in 3 years (not recommended!!!).  After a bit of work, panel purging, and pump overhauls the system is now fully functional.

If you are trying to save on weight the minimum dispatch level of fluid is 3.8 gallons, so you don't always need to fly around with full tanks.  Just make sure there is enough to run the system on occasion.  We typically run ours during cruise to see the entire wing wet out, and then shut it off.  By the time we are back at our hangar the system is dry enough so it does not create a mess on the hangar floor.

[PhateX1337]

Thank you! I saw the empty system weight/arm/moment numbers above in this post and that's what made me wonder if the factory W&B was including some fluid. Appreciate the detail.