TKS installation question.......

[skeptic]

For those of you that have TKS, a few questions:

 

- How are the new wing leading edge surfaces installed?  Are the original skins cut off, with new TKS skins then riveted in place over the wing leading edge? 

- Is corrosion a concern where the TKS surfaces are attached to the original aircraft structure?

- Do the TKS surfaces eventually abrade and "wear out", requiring replacement?  Or are they likely to last as long as the rest of the airplane structure?

- Does TKS installation change aircraft limitations such as load factor, Vne, etc.?

 

Thank you.

 

[johnggreen]

Skeptic,

 

I bought my Bravo with TKS and am no authority.  Still, I think the questions are basic enough that I will address them.

 

The TKS panels are placed over the existing skins.  Don't know of a "documented" corrosion issue.  There was a post on another blog showing corrosion on a Bonanza right behind the panels, but I think they finally determined it was from a bad re-paint job, not the TKS panels.

 

Never heard of an issue with the panels "wearing out" thought they can be damaged from improper maintenance and cleaning.  Proper cleaning is simply mild soap and water or using TKS as a solvent itself and a reasonably soft towel.

 

The operating limitations and performance numbers are unchanged.  Some installations, probably most, result in a slight decrease in speeds, but it is minor.  My airplane seems unaffected as my cruise numbers, verified with 4 point GPS runs, are still about 4 knots over book at all power settings and airspeeds.

 

My system has been almost maintenance free.  I did have to replace a couple of fittings that started leaking, but that was no big issue, and one stall strip became loose and had to be re-glued.  Filter has to be changed every few years also and they aren't cheap.

 

I spoke with CAV aero the other day on another matter and they said that installation on a Mooney is now $56,000.

 

Jgreen

[KSMooniac]

I suspect the post-paint job corrosion was due to a sloppy shop not getting all of the stripping agent cleaned during the process.  I had some corrosion in my old prop spinner that developed after my re-paint, and I attribute it to stripper "left" in between the bulkheads and the dome that sat ~8 months until my next annual.  Ti and Al materials are quite compatible generally speaking... we use Ti fasteners all the time in the aircraft industry thru aluminum structure, so I wouldn't worry about Ti TKS panels sitting on aluminum wing skins, so long as there isn't a corrosive agent sandwiched in between!

 

I wonder how busy CAV is these days with those kind of prices...

[Awful_Charlie]

I bought my Bravo with TKS fitted, and one duff panel.  Getting the panel off destroyed it (they're not repairable in any case) and apparently there was a little 'minor' corrosion behind it, but as it would be unlikely to get looked at again, it had to be dealt with.  The panels are bonded to each leading edge with a few earthing rivets in the corners.

 

Regular maintenance is the odd leak (check and lockwire the fittings) with a filter every few years (easy job, expensive part)

 

The only change to the POH limitation on a Bravo is a revised aft CofG limit to 49.5ins, for speeds and power mine makes book figures or as close as it is practical to measure, but I have heard stories of a 3 or 4 KIAS loss.  Obviously by buying with it already fitted (it was originally delivered with it fitted too) I can't comment any more than that bit of gossip

[bnicolette]

 Getting the panel off destroyed it (they're not repairable in any case) 

I wonder why Wentworth is trying to sell the set on ebay right now if there is no way to remove the panels without destroying them?  Or more to the point, why would anybody buy them?  I suppose there is value in the tank, computer and fittings but the panels are unusable?

 

http://www.ebay.com/itm/140922316570?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

[skeptic]

Thanks for all the great info.....I have never taken an up-close look at a TKS installation.

 

Is galvanic corrosion between the titanium and aluminum a concern over time?  It would seem that any moisture trapped between the TKS panel and the underlying aluminum could act as an electrolyte and facilitate galvanic reaction.

[bd32322]

For a non fiki install on a 252, the quote i got was 38k six months ago.

[Awful_Charlie]

I wonder why Wentworth is trying to sell the set on ebay right now if there is no way to remove the panels without destroying them?  Or more to the point, why would anybody buy them?  I suppose there is value in the tank, computer and fittings but the panels are unusable?

 

http://www.ebay.com/itm/140922316570?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

Wentworth acknowledge that a number of the panels are u/s, and as the wings have been cut, they themselves are u/s too.  I don't know, but I guess there is an option for separating the panel from the wing as to which piece you destroy.  When I had a panel replaced, there wasn't that option!   They are giving the option to take the complete empennage (which has one panel that will certainly need replacing) to possibly avoid the need to remove two of them.  Unfortunately, just because the panel is visually undamaged it doesn't mean it is fully functional though, and they're not cheap parts.

 

As for corrosion, I'm not sure where titanium sits in the league of active and passive, but the function of the bonding rivet is to ensure that they all stay the same potential.  The system has been around many years now, and if it was a problem I would be surprised if it got recently discovered

[bd32322]

Wentworth acknowledge that a number of the panels are u/s, and as the wings have been cut, they themselves are u/s too.  I don't know, but I guess there is an option for separating the panel from the wing as to which piece you destroy.  When I had a panel replaced, there wasn't that option!   They are giving the option to take the complete empennage (which has one panel that will certainly need replacing) to possibly avoid the need to remove two of them.  Unfortunately, just because the panel is visually undamaged it doesn't mean it is fully functional though, and they're not cheap parts.

 

As for corrosion, I'm not sure where titanium sits in the league of active and passive, but the function of the bonding rivet is to ensure that they all stay the same potential.  The system has been around many years now, and if it was a problem I would be surprised if it got recently discovered

Titanium is much less reactive than the other metals ... So if there is corrosion the titanium panel will be unharmed, but the aluminium wing will sustain corrosion

[Cris]

There have been a couple of these systems that have come up for sale from time to time. I spoke to cav to see if they would install the used parts but they were less than enthsiastic. I tried several times to get a quote to no avail, It might be like trying to get an STC from S-tec to install a used autopilot. It's possible but unlikely as there are lots of hoops and very expensive. In the end I decided it would be much more cost effective to sell what I have and buy another with the TKS already installed. Better yet keep what I have and don't fly in any iceing conditions.

[bnicolette]

There have been a couple of these systems that have come up for sale from time to time. I spoke to cav to see if they would install the used parts but they were less than enthsiastic. I tried several times to get a quote to no avail, It might be like trying to get an STC from S-tec to install a used autopilot. It's possible but unlikely as there are lots of hoops and very expensive. In the end I decided it would be much more cost effective to sell what I have and buy another with the TKS already installed. Better yet keep what I have and don't fly in any iceing conditions.

It seems as though it could be a nightmare to go through the hassle of trying to salvage what parts you could then on top of that dealing with the STC holder.  Would CAV absolutely have to do the install?  Would the STC have to be purchased again?  They (wentworth) mention on the ad that the parts come with the paperwork but wouldn't you have to go through it all again and get your own paperwork?  Very confusing to me as I don't have a grasp/understanding on what would be required.

[Piloto]

I have used TKS on planes that I had ferrried over the North Atlantic and here is my 2 cents on them.

 

The system with all the hardware and fluid weights about 80 pounds. So you loose 80 pounds of useful load. Add another 20 pounds if you keep extra jugs in the baggage area and will total 100 pounds loss of usefull load and baggage space or about 17 gallons of AVGAS. Because most FBOs have no TKS or it is very expensive you have to carry extra jugs.

 

TKS will reduce your cruising speed by 3 to 5 Kts 

 

TKS fluid endurance is about two hours. This has been my major concern. Keep in mind that to be effective the wing needs to covered with TKS before encountering icing conditions. I am always concern of running out of fluid for the windshield for my landing. 

 

Unlike de-icing boots that will clear a fully ice up wing upon activation, TKS will take for ever. To be effective TKS has to be on before encountering ice. It is more of a prevention system.

 

I have seen one inch ice build up on my M20J (no TKS) and the worst I have noticed is about 10kts loss in speed but no altitude. If I wax the wing leading edge ice build up is minimum. The new hydrophobic waxes sounds promising.

 

The best way to overcome icing is to avoid it. XM\WX provides the freezing levels so stay away from those. I would rather have a turbo than TKS.

 

For $40,000 for TKS I would rather add a turbo and long range tanks and get more speed, higher ceiling (to avoid ice), faster climb rate and longer range.

 

Some my argue about the above, your comments are welcome.

 

José 

[FoxMike]

Here is my 2 cents on TKS.  I have a factory installed system on my Bravo which I have owned for 9 years.  I agree with all the facts Jose mentions but have a little different opinion.  TKS requires anticipation of ice so before you leave the hangar you estimate your fluid needs.  I seldom carry more than a couple of gallons.  You need to prime the system every couple of weeks or so otherwise it does take a long time for the fluid to flow.  If you do that  you will have a dependable system that will keep the ice off the airplane.  

 

The big question is how bad do you need deice equipment?  Most of the time you can do OK with a pitot heater.  Occasionally, the ice builds and you greatly wish you had TKS.  On rare occasions you get in a big mess and you swear you are going to get the system no matter what it costs.  The TKS will do the job but it is surprising how little you use it.  I have had several experiences where I really needed it but those were few and far between in the 1200hrs I have flown the Bravo.  My previous two airplanes had boots.  I seldom needed them but was always glad to have them.   If you want the highest level of dispatch reliability the TKS is probably a toy you should have.  If you really do not like flying in a mess you are probably can do just as well with just a pitot heater. 

[aviatoreb]

Titanium is much less reactive than the other metals ... So if there is corrosion the titanium panel will be unharmed, but the aluminium wing will sustain corrosion

 

I have a little experience in this from my other main hobby - bicycles.  I have three titanium frame bicycles.  They never corrode despite a very corrosive environment that you sweat on them - esp if I ride on a trainer in the house.  Sometimes pools of sweat. that corrode quickly a steel frame but after many years not a bit of corrosion on the Ti frames.  In fact, we don't even bother painting a Ti frame, thus the distinctive gray of the Ti bike.

 

But one of my bikes had an aluminum seatpost in place for several years and when I needed to change the height at one point (changed shoe model) it was frozen in place after years of galvanic bonding.

[Bryan1016]

This is my first plane with TKS.  Honestly, I don't have much experience with ice.  The few times that I have been in ice, lower was an immediate option.  The turbo puts me up there with it through more months of the year than an N/A aircraft.  Anytime I go through an ice layer, it will be on.  I'd rather be shot at than fly through ice.  Guys like me with less experience will probably get more use out of it.

The stuff is a sticky mess.  Don't test the panels in your hanger.

[Yetti]

On 3/5/2013 at 6:25 PM, aviatoreb said:

But one of my bikes had an aluminum seatpost in place for several years and when I needed to change the height at one point (changed shoe model) it was frozen in place after years of galvanic bonding.

Light coat of grease on post before installing.   Every couple of years they should come out be cleaned and re greased.   I use high temp bearing grease from wally world.   Also keeps them from creaking.   Matter of fact every bolt, handle bar, stem gets light coat of grease.    Yetti sweat is quite corrosive

[Bryan1016]

Doesn't the STC require dual alternators? My 262 has a lot of weight forward with two 80 amp alternators.


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[Jerry 5TJ]

Just now, Bryan1016 said:

Doesn't the STC require dual alternators? 

Yes, FIKI version of TKS requires dual sources of electric power.

[Bryan1016]

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[Bryan1016]

Preparing for Charlie weight in rear to off set alternators...


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[Piloto]

I have tried WD-40 on the leading edge and it appears to minimize ice formation. I don't do too much ice flying so WD-40 is good enough for me. But for the cost, weight and speed loss it surely beats TKS. Give it a try.

José

 

[Guitarmaster]

5 minutes ago, Piloto said:

I have tried WD-40 on the leading edge and it appears to minimize ice formation. I don't do too much ice flying so WD-40 is good enough for me. But for the cost, weight and speed loss it surely beats TKS. Give it a try.

José

 

I gave this a try, but never got in to ice.  It DID make a slippery mess on the leading edge of the wing.

[kevinw]

Having a J with non-FIKI TKS, here's my 2 cents and it's similar to the others. I rarely use it but it's nice to have it when you need it; it also puts my wife at ease in the winter. The system was installed by the previous owner after a scare in icing. Personally, I'd rather have the useful load back with my kind of flying. With a full 6 gallons of fluid the system weighs 98 lbs so in the summer I only keep about a gallon in the tank. I believe it costs me 4-5 knots of airspeed. You should to test the panels once a month and it makes a mess. For someone who does a lot of winter IFR flying I can see the advantages but I'm not that guy so I highly doubt my next plane will have it. As far as corrosion, I was told by a mechanic at a MSC that the fluid itself is not corrosive but it creates a corrosive environment.

[peevee]

10 minutes ago, kevinw said:

Having a J with non-FIKI TKS, here's my 2 cents and it's similar to the others. I rarely use it but it's nice to have it when you need it; it also puts my wife at ease in the winter. The system was installed by the previous owner after a scare in icing. Personally, I'd rather have the useful load back with my kind of flying. With a full 6 gallons of fluid the system weighs 98 lbs so in the summer I only keep about a gallon in the tank. I believe it costs me 4-5 knots of airspeed. You should to test the panels once a month and it makes a mess. For someone who does a lot of winter IFR flying I can see the advantages but I'm not that guy so I highly doubt my next plane will have it. As far as corrosion, I was told by a mechanic at a MSC that the fluid itself is not corrosive but it creates a corrosive environment.

with our K something like TKS is the only thing keeping the airplane from doing everything I want.

Is it still about 50k to add it on?

[kevinw]

16 minutes ago, peevee said:

with our K something like TKS is the only thing keeping the airplane from doing everything I want.

Is it still about 50k to add it on?

Someone said in an earlier post that he was quoted $38K for non-FIKI so not cheap. If I recall, the previous owner told me he spent $25K but this was done in 1998. Said he had a bad experience in icing and scared him into adding it.