I have actually never seen a Cirrus use TKS fluid but I have flown in airplanes that use a Deicing boot which works quite well. Has anybody seen both work while flying and which one is more effective?
Thank You in advance for your response!
Roshard it’s kind of a moot point since we don’t get to choose. An airplane has to be capable to be FIKI certified, so all 3 systems work. TKS is easiest for the manufacturer and most difficult for the owner. It does work when it’s working, but the panels need to be clean (free of wax, etc.) and primed to optimize flow. The flow itself is nice, in that it tends to cover a lot of the surfaces behind the leading edge, but that’s not critical. The downside is the plumbing, pumps and the amount of fluid available. If you’re considering a FIKI Cirrus the system works, but does so in a serious environment so I’d say be wary.
Boots just work. As long as you need them to, with no risk of running out of fluid, etc. They are a more expensive solution and tend to be found in airplanes that lack excess power. They’re ugly, and no doubt extract a speed penalty.
The best answer is heated wings, and that’s what the best equipment uses. Engine compressor air is diverted to heat a pretty, shiny and smooth leading edge and that’s the Gulfstream solution.
You used the term “deice” in your post, and none of these are “deice” answers, merely “anti-ice” protection, though it could be argued that boots deice.
I have a good bit of time with both. Overall ice protection is multifaceted. You have wing size, thrust available, climb capability, engine protection, unprotected surface area, wind screen visibility, among other things that factor in. TKS has an advantage over SLD runback type icing, but can be overwhelmed with heavy Rime where the boots will pop off heavy rime nicely every cycle, but won’t do anything about ice that runs back behind the boots.
Overall the TKS usually makes the wing look better. For an unforgiving laminar wing like the Cirrus TKS is better… unless the tanks go dry, or the pumps quit working. For frequent ice encounters, long trips, and practicality, I prefer boots which are always available, lightweight, relatively maintenance free and don’t make a mess. But the Cirrus FIKI when working is quite effective.
Boots are deice
And tks is anti ice
Having been in incing conditions a number of times in a 2007 SR22-GTS I can tell you that the TKS systems works well “if” the TKS system is turned on prior to getting into the icing or getting the TKS system operating fairly quickly after the icing conditions occur. I fly a BE20 with de-ice boots, there really is no comparison to boots and TKS. The reason is that on a de-icng boot we allow the ice to build up and then shed the ice with the expansion of the inflated boot, TKS does not behave in this fashion, allowing ice to build up and then turning on the system would not have good results. However my company also operates a Hawker HS125-800 with a TKS type system, it works well with the same caveat as mentioned above, getting the TKS system operating and allowing the fluid to enter the wing panels and into the propeller hub (on the SR22) is not instantaneous, a boot system or a hot wing are great but the option is not available on this and many other aircraft. Another very important thing to remember is the amount of TKS fluid one has on board, not much if I recall in my model is was 5 gallons, enough to get you out the ice and onto the ground quickly with little delay. When It comes to icing in any piston, light turbo-prop I keep in mind the lost of life accident of the TBM-700 in icing conditions:
Thinking your plane can handle heavy icing will get you into trouble. Planes with good icing systems is there only to give you enough time to get out if you happen to get into it.
From my use of boots, that is all they do is de-ice. No anti-ice benefits
Rob,
Hadn’t seen that video before. Really sobering.
-john
This video is worth watching.
I just had a thought. Is it possible that the pilot used the boots and perhaps only one of them dropped the ice , causing a servere performance difference between the wings ? Or is it more likely that the aircraft just stalled at a high airspeed and was unrecoverable. Good video. Thanks
Not sure that we will ever know exactly what happened to that TBM. Modern FIKI testing requires the plane to be tested with asymmetric ice accretions that might occur with a boot or TKS panel failure, but not sure back when the TBM was certified if that was a requirement. Icing certification continues to get more stringent and even looking at the difference in the deice system of the Malibu/Mirage certified in 1984 versus the Meridian certified in 2000 the deice systems have evolved. The biggest difference to the eye being the size of the boots. The Meridian has boots that are twice as big as those on the Mirage or TBM, protecting more of the wing cord. Engineers by then had knowledge gleaned from the Roselawn accident which involved SLD. Among the many recommendations from that investigation, was to extend the boots back on the cord to help with heavy ice and SLD.
I think that the TBM was actually at a relatively low speed looking at the ground speed returns on flight aware, and likely high AOA. He may have got an AP disconnect with a potentially out of trim plane, followed by a LOC, versus a stall at high AOA, which would be difficult to recover with a contaminated plane. Does not sound like a spin since he tore the plane apart. A spin shouldn’t overstress a plane, whereas a death spiral will. Since a heavily iced plane can stall at 30-40 knots higher than its non-contaminated airspeed, if he would have just pointed the nose down if he was having trouble maintaining air-speed, he would have had plenty of potential energy to keep flying. Plus boots work better at higher airspeed.
I am just guessing. I think this accident is one of those very interesting to light turbine drivers, because the conditions did not seem particularly menacing. Looking at what was available at time of launch, I think I would have departed as well.