So, I’m sure that some of you have inadvertently picked up some ice on your 22 along the way.
I may need to penetrate a small bank of clouds below freezing levels (0 to -10) on a x/c tomorrow from (about 60nm/20 minutes in the clag). I’m wondering what the chances are that I will pick up ice. I’ve always assumed 100%, but I know that that’s not necessarily the case.
How risky is this? I’ve always come from the “never enter visible moisture if OAT is < 0” school. I’d prefer to keep it that way, but I’d rather work off of knowledge than superstition.
Short answer–make really really sure you have at least one iron-clad way out at all times. Classic traps–freeze level is below MOCA, no VFR weather below, etc. Also, go read any article about tailplane stalls, just to make sure you’re sufficiently worried.
When I was in training for my 20, the Wings Aloft people told me that they had several icing encounters (being northwesterners, they were pretty blase about it) and they told me that it affected the 20 more than most airplanes, at least in terms of initial airspeed loss, and that it did not seem to shed the ice as quickly as most planes, perhaps due to being clean and white.
But whatever you do, don’t get into it unless you know exactly what your bailout option (or two or three) is going to be at all times. Figure that you will be forced to keep high airspeed and won’t be able to hold altitude, and then work your scenarios.
One mistake that has killed pilots is to try to “pop up” when they started picking up ice; trying to gain altitude quickly resulted in a loss of airspeed, and once you get some ice on the airplane you need to throw the stall charts out the window. If the tailplane stalls on you, you’re pretty hosed (and the recovery is counterintuitive.) I think there’s been an Avweb article about this recently.
Paul
Last weekend I picked up some ice on purpose on my 22 to see how it handled. I was at 5,000 feet. The OAT was -1, the tops were 6500 feet and the temperature at 4000 feet was above freezing so I had two simple escape routes. I got about 1/8 inch only on the leading edges. Other than a 5 kt drop in IAS I didn’t note any difficulty with the aircraft. I would however really try to limit exposure to ice as much as possible. My personal requirements for entering conditions conducive to icing are to ALWAYS have a way out (short climb to known clear air, warmer temps below, terrain that allows a descent or a 180). If there are pireps of actual known icing and the clouds are not just 1-2 thousand feet thick I wouldn’t go. Remember, any ice is significant and significant ice is really bad in any light aircraft.
Jerry Seckler
Paul, I’ve inadvertantly picked up ice on my ‘22 on two occasions. The first, some water drops already on the wing froze, the second time was typical rime ice with accumulations well below 1/8 inch. I noticed no affect, but only used 1/2 flaps on landing and made sure to keep my speed up. I also put the flaps in well at least 2,000’ AGL.
I did not have to add power to maintain altitude and I can not remember if I lost some airspeed, but I doubt the effect was any more significant than it is with wet wings.