Yesterday I was out with an instructor working on instrument approaches in our PA-39. We are based in northeast PA. OAT was about 20 degrees Fahrenheit or less. Practicing holds at 5000 when we first encountered the ice. Lots of humidity in the air. Perfect recipe for rime ice. All the leading edges of wings and tail surfaces got about a 1/2inch or so of ice on them in about 3-5 minutes.(kinda spooky how quick it happens) So, naturally we descended into the warmer air. As the Ice melted some of it got slung off the props. I could hear it hitting the side of the airframe. Since its a counter rotating twin, all the ice on the right side got thrown against the nose cowling and beat up the paint to bare metal about a baseball in size. Looks like it got into ice before and was repaired because I can see bondo in and around the chipped paint. My question is, has anyone here installed ice protection plates on their twin? I see a lot of twin cessnas and other bigger twins with them installed but I have never seen a twin comanche with them on it. Any input would be greatly appreciated at always.

I have considered it, but haven't done it. I am familiar with them on Navajos and Aztecs. I don't know anyone who makes them for the Twin Comanche, so I figure I am going to have to make the from scratch.

I may be mistaken but if memory serves; I think Bill Schnauffer's "Miss Scarlett" (2013 Flagship) has them installed. I'm also pretty sure there's a PA-39 here at my home field with them. You might contact Bill and ask about his plane, or... It's maintained by Cliff Wilewski's team at Heritage Aero - maybe try giving Cliff a call and see if he knows. Have you called Webco?

- Charles

FYI,

About 20 years ago I remember talking with somebody in Canada who had them STC'd. but I never hooked with them and couldn't track any other information down. I remember that they were similar to the Navaho and possibly a little thinner. FWIW.

Jeff Aryan

Jeff et al... I just sent Kristin 3 photos of these on a PA39... she can post them on the Delphi site, I don't want to "consume" my allotted posting space there and I am confused on how to post them here.

All the best!

Jim

Here are two of them.

Kristin,

Thanks for posting. I haven't personally been PIC when ice is coming off the props but have been on board when the drums are being played on both sides of the nose ... when I got the Twin painted, the bondo was removed and metal pounded out.

If we still lived up north, we likely would have plates. Even when ice is not forecast, it just happens in moist areas like Chicagoland.

Kristin,

Thank you for the pictures, very interesting. Do you have any information on where to get them, how much, paperwork associated, etc. Also, are they removable or a semi permanent installation. I was just thinking out loud, it might be a good thing if you could remove them for repair and/or new paint.

Jeff

Jeff... I think that they are pretty permanent... rivets are used for mounting. The pictures are not of my airplane, but I did see this airplane in the paint shop and the photos are specifically after the paint had been repaired. Look for an email in your regular mailbox.

Jim

I think that they could be installed with rivnuts which would make them removable. There is a question in my mind as to whether they would be considered a major alteration. I am leaning towards no, but I haven't analyzed it. I know how to make them, I just have to find the time and motivation to do it. Once I have made the molds to lay up fiberglass, it becomes fairly easy.

Kristin,

I am also interested in the Ice Plates. I have seen some ice plates that are about an 1/8-1/4 inch thick while others seem like 1/2-3/4 inches thick. I am leaning toward the thinner ones. It would just seem easier to repair and repaint and overall look better incase you had some damage. It's just a thought.

Jeff

I have these plates on our full deice PA39. They are about 1/4 inch thick, riveted on, and they are made out of some sort of plastic. I do not have a form 337 or STC that mentions these specifically. If anyone is considering making these, I would suggest that they be wider. There are more ice impact marks just outside of the edges than on the plates themselves. I also have a chip in the plastic right on the edge of the plate from ice damage. This chip happened when I learned the hard way that the prop anti-ice needs to be turned on well before entering icing conditions. Based on ground testing, it seems to take at least 30 seconds to get the alcohol flowing to the props.

Ed Rognerud
Rosemount, MN