To Test the Escape Pod

caps_activationhandle

The Handle of Last Resort

Those Cirrus planes have a handle inside, on the ceiling between the two front seats, but actually accessible from the backseat as well, that is hard to pull. That is so you don’t pull it by mistake. From what I understand, you basically lift yourself out of your seat using the handle, that’s how you pull it.

When you do, nothing hugely mechanical happens. The force required to pull the handle is all just added. They could have made it a push button, they just didn’t want anyone pushing it by mistake. The handle pull makes a connection that activates an ignition system that blasts a rocket (yes, a solid fuel rocket) through the skin of the aircraft, just rear of the back window (a sort of skylight over the baggage compartment). Whoosh. The rocket drags with it a parachute and shrouds (lines connecting the aircraft to the parachute) follow the ‘chute. Straps connect the shrouds to attachment points on the wings and tail and the straps pull up out of the skin of the aircraft like tin foil hidden under the smooth icing of a wedding cake. I don’t think anyone knows what that sounds like because there’s a rocket going skyward when it happens.

chute-water

On the way to Haiti…

Then, bang, the plane is suspended under the canopy of the parachute, swings for a moment or two, and then gently descends toward the ground. (Well, 1,400 feet per minute. I am not sure I would call it gently. It’s a wonderful alternative to dying, but I am not convinced it is better than putting the plane down on a beach, golf course, or farmer’s field. Great as an option, especially at night.) The plane is a total loss at this point, but Cirrus promotes “Pull early, pull often,” as a way to save the lives of the (potentially four) people in the airplane. There are some dramatic stories of lives saved using the system.

If I owned a Cirrus I would wonder a lot about that handle. What is it like to pull it? What are the sounds like? What is it like when you are floating down under the canopy? (A guy on his way to Hawaii had to pull the chute and he shot video of himself doing it.) It is strange to me that you transition from flying a plane, which all about control, to being a passenger as it falls toward the ground like a skydiver who spotted the landing zone.

And, deep down, there is that feeling, how do I know my escape pod works if I don’t try it out? Even though trying it out will be destructive, it must be something you think about.

I know I think about it. And I don’t even have one. I do have an escape pod, of sorts, for icing. And I tested that on Wednesday, which was a little less destructive.

Ice accumulating on an airplane will distort the lifting surface, smother the engine, and jam the controls. It also adds weight to the plane and I guess that’s the only way you can add weight to your load once you leave the ground. None of these things are good so there are three ways I know of that aircraft manufacturers keep your craft free of ice:

1. Heat the wings up. If you’re flying a jet, that’s pretty easy to do. (Easy for me to type, since I’m not the engineer that had to figure it out.) You divert just a little bit of air from the back of the jet engine over to inside the leading edge of the wings and tail surfaces. Nice and toasty, this is called “bleed air.” With the surfaces warmed, ice cannot form. (A few years ago some small planes used an electrically heated wing surface to try to do the same job. Seems like a clever use of electricity your plane is already set up to generate.)

2. Change the shape of the leading edges. Some guy at BF Goodrich (probably employed in “figure out some more things to do with rubber” department) figured this out in 1931. You make a “boot” over the leading edge, sort of like a pair of galoshes, it is a snug fit. The plane flies normally with the boot on. When you are worried ice is going to form, or has started to form, you trigger a pump. “Blowing the boots,” is a term I have read. The pneumatic pump forces air into the boot, expanding it and deforming it. Ice is brittle and it cracks, separates and just falls away. (Circuitry is set up so that the boots are inflated (and then allowed to deflate) on a regular schedule. Every five minutes or something.

3. Coat the leading edges with goop that discourages ice from forming. This is actually done on the ground with big planes, they spray them with goop since the bleed air doesn’t heat enough of the wing and is not powerful enough when the planes are taxiing around on the ground (at low engine power). This is popular with smaller planes because you have a fairly simple system that puts the plane in a different category of usefulness. Being able to take off into conditions that are known to produce icing is such a big deal that the FAA certifies the plane separately to do that. And, like all good things in aviation, it has an abbreviation: FIKI (Flight Into Known Icing, fee-kee).

Personally, I think that if you take off in a small plane, even one with two engines, knowing that you are going to spend a significant period of time collecting ice on the airframe you are bonkers. I won’t ever be doing that. I wouldn’t even do it in a small jet. There was a crash a couple years ago of a TBM turboprop over New Jersey that was brought down by ice (that plane has the boot system). There is always a limit to what the system is capable of and if you fly into a place where the ice accumulates faster than whatever system you’ve got, you are in just as much trouble as a plane that didn’t have the system.

No, for me it is an escape pod. I do not plan to be accumulating ice. But if I am flying along in the blue sky, I want to descend and land at Seattle, there’s a layer of clouds, and it is below freezing, I know I am now equipped to try it out. The controllers are always very helpful, and if you start accumulating ice you can always climb back up, drop out sooner, or turn around. No one forces you to stay where you are picking up ice.

The ferry pilot said, “The icing system should be triggered before you go into the clouds. Just run it long enough that you see the fluid crest the curve of the wing. Then you know it is protected. Once you are in the icing conditions, then turn on the system for more constant protection.” Seems so easy.

So I tried it on my flight from Friday Harbor to Portland. It was evening, but not dark enough to use the “ice light,” and I couldn’t tell if the fluid was seeping out over the wing. I gave up, since it’s not like I was headed into anything other than light rain. (When I asked about testing the system, the ferry pilot said that it was no fun to test because it left sticky, messy goop over the wings and dripping on the ramp. I figured flying into some light rain was a great time to test it.)

Talking to my mechanic in Long Beach I had a few little tasks for him. The map light for the pilot was out (not a huge deal since I carry two flashlights, one of them a head lamp, and the co-pilot map light can be aimed over to light up my kneepad), there was a little rust on the support for the pitot tube (I wish they had taken care of that at the annual), and I am pretty sure the sump drain valve on the left side was leaking. I said that while I was down there I wanted him to go through the FIKI system to test it and show me anything I needed to know.

I flew down on Wednesday morning. It was a perfect flight and I am getting much, much better in the plane. I am ahead of it much more often now and my landing was gorgeous. I need to hop on the brakes a little faster. I am always so surprised that things have gone well that I sit there for a moment, enjoying the roll like I am a passenger. No no, grab those brakes.

It was warm. I don’t know how Dave (my mechanic) stands being in the sun so much. His entire crew was in the shade of the hangar working on two other Twinstars and Dave had them park mine in the sun while he crawled around inside getting the LED bulb into the map light and changing the sump valve. I cleaned the rust off the support for the pitot tube and Dave hit it with some corrosion protection fluid. Then we were onto the FIKI system.

sweat

Sweating it out

He turned it on and the pump hummed. A moment later the micro-mesh metal panels on the leading edge of the wings started weeping. It was like they were sweating. Dave walked back and forth on the wings, wiping the fluid up onto the portions of the panels that were further out on the wings. It seemed that as he did that, it encouraged more fluid to come out further along the panels. Eventually, after about eight minutes, there was a pretty consistent dripping all along the wing. There was one portion on each wing, about eighteen inches long, that remained dry. Dave said that if we really wanted to see the whole thing pump fluid we’d have to tape off the working portions to force the fluid further up the path. That happens naturally when you are flying, there’s a lot of pressure against the wing, but it’s difficult to simulate on the ground.

tail

Eppenage panels all working flawlessly

The system, which in my head I picture as just a tank with some clear plastic tubing and little electric pump humming away, is actually pretty complicated. There are units that measure and regulated the pressure in each section of hose. The wings each have two hoses running to them and the wing is divided into two panels, fed separately. There are panels way up on the elevator (out of my reach), and on the stabilizer (in front of the rudder). There are little spigots that feed the propeller hub and a separate set of controls to trigger a sprayer bar for the windshield. (Apparently the windshield spray isn’t really necessary because you keep that clear of ice by having the defroster going full blast if you are in icing conditions.)

wings

Little dry portion noticeable by the dry patch on the ground

I flew back home very satisfied with how the system was performing. Like that handle in the Cirrus, I know that I don’t want to be in a situation where I try out my escape pod, but on the other hand I sort of want to know what it is like to see ice accumulating on the unprotected portions of the airframe (apparently the black metal fins around the fresh air vent are a place to watch), while seeing the ice shed off the wings where my FIKI system was operating.

It’s too bad there’s not a way to train safely in icing conditions. I would fly the plane to somewhere to get the experience. In the Colgon crash over Buffalo the First Officer can be heard on the cockpit voice recorder complaining that she really didn’t have much experience flying in ice. The captain is then reassuring her that she’ll gather it as she flies more in the northeast. As he’s saying that ice is accumulating on the wings and will eventually put them in a situation where they react improperly, dooming everyone on board.

My goal is to not make that mistake.

ice-da42

Actual DA42 after actual instrument approach in icing conditions

(The above image is from a post on Reddit, the pilot had flown down through icing conditions on his approach to the airport.)

About Colin Summers

I am an architect, programmer, private pilot, husband and father. A couple of those I am good at.
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2 Responses to To Test the Escape Pod

  1. Ron Rapp says:

    If you really want to try deploying the BRS, there is an SR22-specific simulator in Las Vegas which has a pullable handle. I don’t know if the force and sound are realistic, but it does allow the CFI to put students into situations where the BRS is the best option. Great training.

    I commend your cautious attitude toward ice. Mother Nature can overpower any aircraft. Does your DA42 have a periodic maintenance procedure where you run the TKS system in flight? On the Cirrus they recommend doing that every month or so in order to keep the panels clean and avoid drying out the spongy material on the backside of the panels.

    • Owners seem to run it once a month if it is something they use during the year. My plane was in Tennessee at a flight school and as far as I can tell they never used the aux tanks and never used the FIKI. That was one reason I tested it. I figure I’ll run it every other month, maybe note it on the page where I do my VOR checks.

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