Yes. I think my point was that the two systems are exposed to different factors which can render them inop.
The tb20 has only TKS as an option and owners I have spoken to have reported it as capable of handling any icing conditions they ever encountered.
mh wrote:
Yeah, but then no system can fix stupidity or maintenance neglect.
And you can substitute any system for “boots” in that anecdote. It indicates a maintenance problem not a problem with boots.
Peter wrote:
and owners I have spoken to have reported it as capable of handling any icing conditions they ever encountered.
I would take that with a grain of salt….
Yes. I think my point was that the two systems are exposed to different factors which can render them inop.
Not really. One is very rare (boots). One can happen all the time if you are not careful and refill the tank, bleed the wing panels etc.
Peter wrote:
The boot debate is moot since no type of aircraft has TMK had both options
Cessna 210, Bonanza A36
Dave P YMMV, the FIKI PA31 is not immune to icing accidents. My experience in the past and over a reasonable exposure period, around 1,000 hours on piston twins, is that I can think of three occasions where the boots (in good condition) were overwhelmed (my criteria is loss of 20 KIAS and inability to climb). An actuary might suspect the FIKI certification was a bit generous on those odds.
The three events were linked to convective or combination of convective and orographic conditions, one I was actually in the clear.
TKS is an anti icing measure, not a de icing system, hence I would suggest most effective with a turbo charger as you are using it to climb on top.
aart wrote:
C210_Flyer, I am puzzled by that 7 kt speed loss. I know for a fact that there is no speed loss on the DA42.
Have you been able to do extensive measurements?
Well I think with the factory install it is part of the wing. Whereas in the add on version its placed over the leading edge. So if you run your hand fore and aft over the leading edge you will feel almost a ridge. So Im sure that changes airfoil to some degree. My understanding from people is the boots on the prop decrease IAS by about 5kts. So between the prop boots and the changed leading edge I figure a 7Kt loss.
Another reason I cant fly into Zell Am See and feel comfortable. Longer TO roll.
Dave_Phillips wrote:
In the same role, I also fly a weeping-wing DA42. You MUST be ahead of the game here. Firstly, if the leading edge is frozen and you then operate the system, at best, you will get an uneven distribution of deicing fluid and the reality is that moderate ice will not clear.
Agree up until you said , “and the reality is that moderate ice will not clear”.I have had moderate ice if one is late in using it. What happens is, as the ice builds the TKS underneath causes the ice to lose its grip. The more ice the easier it will be to loosen it in the airflow and have it shed. Ideally you want it on early so the ice does not adhere.
As for windshield if you are a single it does in fact cover it very well as it does most of the fuselage. Of course how could it possible cover the windshield of a twin or its fuselage?
Peter wrote:
On the tb20 you lose about 50kg payload if you keep it full. It lasts about 1hr on max so is no good for enroute icing protection. In that respect boots are better.
I use mine enroute all the time. I have 2.5 hrs anti ice and 1.5 hrs de-ice.
Here is the deal, as part of your preflight you need to charge the system if you think you might get into more than just a little ice. Which costs money and most people wont do it.
Here is why it should be part of the preflight.
Problem 1. If one of the panels does not work its not good news especially if its a panel that you cant see.
Problem 2 If the system is not charged it will take a few mins to get it operating and ooze out the panels.
Problem 3 If you wait to charge the system till you are collecting ice it will take more TKS fluid to remove the adhered ice.
Charging the system takes about 1/2 to 3/4 of a gallon. So its not cheap to do. I think that is why most pilots who dont fly IFR regularly have failed pumps, its due to inactivity. TKS recommends cycling the system every 30 days.
I have no problem picking up ice even in June flying over the mountains going to Greece.
Is the system worth the cost and the expense of the fluid plus the loss in IAS. You bet especially here in Europe where the airway MEAS are pretty high.
That makes sense. I am a bit surprised by the speed loss from the prop deice, given the rubber bits are at the wing root and just direct the fluid to the blades, but 2-3kt speed loss from the wing deice system is in line with my before-after observation on an aircraft I flew before and after the TKS installation.
Completely agree with regard to priming the system. It is interesting to see how long it takes for the fluid to get to the panels, and how uneven the distribution initially is until the system settles down.
I am sure there is no speed loss due to prop TKS, on the TB20. Mine does exactly he same IAS at low level (138 IAS for 11.5 USG/hr) as non TKS 3B or 2B prop models.
Today was an interesting illustration of where one would not get out of Salzburg LOWS back to the UK even with full TKS – see this post for the wx data. The IMC (definitely icing conditions IMHO) would have lasted longer than the TKS, unless one climbs to say FL200 and then you will probably get this if the OAT is around -15C. That’s unless prop TKS protects from that… I have not done a comprehensive test on it.
But I am convinced about the value of full TKS. I just hate the thought of unleashing some load of cowboys on my plane, all over again 
@C210_Flyer Given the choice between a C210 with boots and one with TKS, which would you choose (everything else being equal)?
This useful data point came by me, from March 2006, quoted by Air Touring (a Socata disti who went bust about 2008)
