De Icing and Anti Icing

[Skymaster69]

After experiencing a significant icing incident I am extremely cautious about winter IFR flying. I own a C421 with boots but personally prefer flying my T337G-P. Unfortunately the Skymaster has no ice protection (other than pitot heat). Options of installing boots seem price prohibitive. However I note a recent article in "Plane & Pilot" about after sales installation of TKS by Aerospace Systems & Technology (www.weepingwings.com). This system appears to have many advantages over Inflatable Boots and note they appear to have STC approvals on several older aircraft including Cessna 206 but not on the 337.
My question if anyone has any further information on the TKS system alternatively info on any viable Anti Icing & deicing options that could be installed on my 337? Thanks

[Mark Hislop]

I have talked to TKS many times, including speaking to their president at Oshkosh. They have no interest in doing the STC work required for the Skymasters. I even tried to induce him with a "group buy" of 5 or 10 planes, and he still was uninterested. Too bad, because I think it is a great system.

However, even if they did produce TKS for the Skymaster, it would be about the same price as putting boots on.

Mark

[WebMaster]

I would comment that while your 421 is certified for known ice, the 337 with de-ice equipment is not.
I have seen the TKS system in action, and it is quite impressive, even does the bottom of the wing, important during climb out.

[Dave Underwood]

Icing is always an interesting subject and I thought I would add my two cents worth.

I have had numerous trace and light events. Generally the ice disappears quickly after climbing or decending clear. I also actively avoid it and immediately demand to go lower or higher. In many respects I think it is very important to stress the urgency to ATC, as they seem complacent because of dealing with the big guys who don't have our issues.

I have the standard install, now with new boots that works pretty well. The only issues I have are that I have lost stall strips on several occasions when running the boots and the need to replace the exhaust solenoid on the front firewall. Both require some searching for decent prices. The stall strips are contact cemented on, but disappear during inflation, as there is no defined pad for them.

Shortly after getting the plane, I had a significant ice encounter with about 2" of rime and some clear on the leading edges when we landed. That was before I had working boots and strong motivation to get them working.

It was not nice with the whole plane rumbling and bucking a fair bit on the approach. By keep the speed up, things remained under control, and manageable. We were doing +100 knots over the number and touched down at pretty high speed. Fortunately I was with an instructor friend who had lots of time in 337's, but he was tense and most of the approach was flown at +120 knots.

BTW, it was a very localized event that happened very fast with neither the plane in front nor the one behind reporting much of anything. The joy of a bit of cumulus with good development and low freezing levels.

I have a suspicion that the aerodynamics on the C337's in icing conditions are not straight forward and that is one of the reasons Cessna did not go further forward. If I recall correctly, most of the rumble was through the controls and I suspect tail plane buffeting and stalls are the real challenge.

If anyone has additional experiences and/or knows of the results of the Cessna experiments, could they let us all know. We can all learn from the experience of others.

Blue skies - Dave

[Paul Sharp]

I haven't heard anything about the 337 being different from other planes so far as controls and buffeting are concerned, but I did hear that Cessna, after much flying around behind the "icing" aircarft during tests, eventually came to the point where they couldn't keep all that tail surface area from building up too much. My plane has the tailplane boot just like others, and I think it would provide adequate de-icing for a while (as always depending on the buildup rate), so I feel fairly safe as de-iced planes go. But the boot only works for the leading edge and I could see where it could eventually build to a point where there was just too much weight on the tail, etc. That of course would affect the flying qualities as well as the tailplane stall characteristics. In any event, I consider my deicing to be for getting out of it and as a safety valve for inadvertant encounters and not for flying around in the stuff. That seems to be the generally correct view of ice equiptment these days, anyway.