This was my first real icing flight. Oh, all sorts of things spring to mind, like “Shaken, not stirred” and other bartending jokes. Since I’m not a drinker I’m not even aware of all the great possibilities. I’m going to stick strictly to the facts instead.
In a decade of flying I have encountered icing twice, both time inadvertently and both times in our original plane, a DA40 which has no icing protection. The first time was during an IFR instruction flight with my CFII. She had a bad experience in ice when she was a student, so we took it really, really seriously and had all sorts of different plans for what to do and when. It was a non-event. The second time I was the only pilot on board and, once again, I had a succession of plans to address my situation if certain things happened. They didn’t, I descended into warmer air and everything was fine.
So having a plane with a protection system so robust that it allows for Flight Into Known Icing (FIKI) is an entirely different mindset. I am meant to be picking up ice. The question becomes one of performance. Is the system doing what it is meant to? Am I shedding enough ice that I am safe to continue the flight?
Like many things in aviation, those decisions need to be informed by experience. And experience is hard won in aviation. There is no magic airplane that always does what is necessary to keep you safe. Gravity is going to always return you to earth, so it is just a question of when and how. Nature is much more powerful than anything we have dreamed up to overcome it, so it is really a question of when to surrender and where you are when you make that surrender.
With icing, I read as much as I can. Of course, one of the things I read is the NTSB reporter and I always think about this accident, where an incredibly capable airplane, one that I will never be able to afford or have the training to fly, was overcome by the icing conditions until it dropped out of the sky killing the pilot and four family members.
I am sure when he was preparing for the trip he knew there was going to be icing, as there had been on other flights, but his three million dollar plane was capable of handling that (primarily by changing the shape of the wings’ leading edge, a device called a “de-icing boot” and by being able to climb so fast that the plane is only in the icing conditions for a short time). And he was wrong.
At some point, you have to recognize when you are wrong and take action. These are all things I had in mind as I prepared for the flight.
It was not a routine flight (I don’t usually head to Palm Springs on short notice). My friend Susan is also a pilot and I’ve flown her DA40XL a bunch of times (including once to collect Rudy from a summer job). She needed to get down to Palm Springs for a business meeting and was going to fly down. I had helped her brief the weather. Then she arrived at the airport and found her plane flooded. It rained yesterday and apparently she has a leak in one of her canopy seals, so there was a few inches of water in the rear seat footwells, the headsets were all wet and who knows what else. When she bailed the plane out like a boat and plugged in the headset to call the tower they said, “Carrier, no voice.” So the microphone was inoperative.
That was probably for the best since I think the first flight the plane should take is down to the shop to have the whole thing dried out and checked thoroughly. She had to make her meeting and now it was too late to drive. Plus the weather was flyable, but rainy through the Banning Pass which usually means terrible traffic on the I-10 to get down to Palm Springs.
I said I could fly her and met at my plane. The usual thorough pre-flight and we were rolling up to the run up area. The tower read us our clearance, which had us flying up to 11,000 feet to get over the mountains around Palm Springs. We took off and once the wheels were up I turned over the flying duties to the autopilot. We climbed in a slow, right turn until we were passing over LAX and heading along the coast. The controllers turned us toward Mount Wilson and kept climbing us in steps. For a long time we were in clear air above the clouds and then, before we reached the mountainous terrain we entered the clouds. We kept climbing.
I told Susan that when the temperature dropped below 46F I put on the stall warning and pitot heat. That was way before any ice could form, but turning them on was free and I figured that when it was closer to the freezing point I would be busy doing other things and I’d hate to have forgotten that. And I said that in the new plane when it got to be 35F I turned on the TKS system to wet the wings, just in case.
Sure enough, as we climbed through 10,300 feet the temperature was 31F. I already had the pitot heat on and had flipped the switch to run the fluid onto the wings. As we leveled out at 11,000 feet the temperature was 28F. I asked the controller if there were any reports of icing along that route, particularly from small planes. He said that he hadn’t had anyone along the route in a while, but the last ones had reported negative turbulence and some light rime icing. I said that we were minimally equipped to handle icing and that if we started to pick up too much we would need an immediate escape route. He said that he would turn us south for a descent and pointed out some of the airports in that direction. That was a good piece of a planning to have in place.
It was a little bumpier inside the clouds and, as before, having the synthetic vision is a huge help for the psychological stress of not being able to see where you are going. We watched the ridge of mountains crawl toward us on the screen. Then Susan said, “Look! Ice!” and there it was, a tiny piece of ice that had formed on the black plastic edging around the engine intake. And a little more on the back metal fins. We could see the TKS fluid pumping out along the wings.
When frost formed on the windshield I showed Susan how a button press on “Windshield” dumped a bunch of alcohol (and sugar, to keep it stuck to the surface) at the base of the windshield and the ice was washed away. It’s a very comforting demonstration, the ice is forming on the surface, press, and you watch it vanish. So we motored on toward the Thermal VOR and listened to the TKS pumps grinding away.
After twenty minutes of it we could see two patches on the wings where the TKS fluid was absent. That probably means there’s a blockage in that hose, since the screen is broken into 18” sections, each fed by a separate hose, all meeting back at a pump. We also started to hear the ice from the propellers getting flung off and banging into the nose. That’s a sort of garbage disposal noise, and it sort of grinds up through your feet on the floor. As with my other icing encounters I had a planned escape (turn 140 degrees right, descend two thousand feet to warm air). I discussed that with Susan. I checked in with the controller and said we would like to descend to warmer air as soon as that was possible. “That will be with the next controller and it will be in about ten miles.”
Susan said, “This is a big boy flight.” It’s certainly not one I could have done in the DA40, although I guess a Cirrus could have handled it.
Ten nautical miles. 144 knots of true airspeed and a little tailwind. So less than four minutes. It sure seems long when you are watching the ice form on the wingtip (an unprotected portion of the wing that isn’t a control surface and doesn’t affect lift). But sure enough, we were switched to the next controller in a minute and three minutes later he asked us to descend to nine thousand feet. As we were coming through ten thousand he cleared us to seven thousand, so we just got warmer and warmer. At nine thousand feet we still had a patch of ice on one wing, but by seven thousand it was gone.
We were allowed to descend to four thousand feet at Thermal, but I need to study the approaches into KPSP. It seemed that the Yankee approach was something pilots had to request and the minimums are a lot lower. It didn’t matter, there was a scattered layer at 500 feet and with the synthetic vision I was headed directly toward the end of three-one left. I set it down and we were parked a few minutes later.
The return flight was just VFR, with a quick duck through the Banning Pass at 3,500 feet. That’s a little low through the pass (I was counting cards at the casino as we went by), but it was less than ten minutes and there was no other traffic in the pass. A few minutes later and we were watching the warmth of the ocean melt away the clouds over the Los Angeles basin.