Thursday, September 08, 2011

In Concert with the Season

It's warm on the ground, but we're headed back to the flight levels today so the operator has cleaned out the local Canadian Tire of chemical hand and foot warmers. I've also noticed that just having a clipboard on my lap made a difference to warmth, so we have taken a sleeping bag out of the survival kit to use as a sleigh robe. I think the American for that is car blanket, but I like the imagery of sitting behind trotting horses on a frosty morning.

There's no delay on our clearance or departure and we're soon in climb direct the project area entry point. Through ten thousand feet, checklist item: oxygen on. Through 18,000', checklist item, altimeter set to 29.92. Level off and go to work. At first it's warm because it takes a little while for the warm air we've carried aloft to be replaced and/or cooled by the subzero air around us, but inevitably it happens. "I'm ready for those footwarmers now," I say, and then I untie one shoelace and fly with my sock foot for a bit. Cold. There's a bit of shuffling and swearing from the back as the operator realizes he has disconnected his oxygen while searching for the Canadian Tire bag. He takes a few deep breaths, regains his equilibrium and then passes the first footwarmer up. "It's already broken and mixed?" I ask. He says yep, it should be starting to work now. It doesn't feel warm yet, but I put it in the toe of my shoe and put my shoe back on, then repeat for the other side. Not warm.

That's what you get for buying handwarmers in the summer. These things work because of an exothermic reaction between two different chemicals. Old stock. The barrier must have broken down over the last year and the chemical reaction was spent to no one's benefit. I squish my toes a bit and ask him again if he's sure he mixed them or shook them or whatever. He says the instructions just say to take it out of the package to make it work. It is at this moment that I realize there must be two varieties of chemical handwarmers. The kind that heat when two sealed chemicals mix, and the kind we have, that react exothermically with ambient oxygen. Pro tip: if there isn't enough oxygen for a human to breathe, then oxygen-activated footwarmers aren't going to work either.

We descend out of the flight levels to do some low level work. I filed this flight plan as a "Y": IFR then VFR, but I still have to say the words "cancelling IFR" to make the transition. Now that I don't need them, the footwarmers warm up. The low level work has the fuel low level light flashing before we land, but my calculations after we fuel show that we landed with 30 minutes in the tank.

The FBO guy carries my bag for me. "You don't have to do that!" I protest. "There's lots of things in life you don't have to do," he says. The hotel is nearby and Gene Simmons' bus is parked outside. So at Slave Lake we got everyone from Nazareth to Susan Aglukark to Dwight Yoakam and here we get Kiss. Northern concert tours are the best. Enough people come from surrounding communities that the size of the audience can exceed the population of the town.

In the restaurant I ask the server what the veggie burger is like. She says "I don't know, I'm not a ..." then midsentence realizes that non-vegetarians can eat vegetarian items and ammends it to, "I've never had it." She's confused when I want to know if she knows anything about it.

"If you had a "meat burger" on your menu customers would ask you what kind of meat it was. What kind of vegetable is this? Rice? Beans?" She doesn't know but I order it anyway and five minutes later I hear another customer asking the same question. She does come over to find out what it's like, so the next customer will be able to get an answer. Dessert is Turtle cheesecake. No question there.

Next day's work is two projects in one in the city of Edmonton. I'll have to send the controllers a map so I can negotiate for each line, but neither map is any good. The maps are different scales, don't cover exactly the same area, have the rong landmarks on them and are completely unfaxable. I redraw it on a separate piece of paper, showing only the river, the major roads and the reporting points the controllers will know. I'm interrupted once by a fire alarm, but get it all done in time to meet the operator for a bedtime snack. We had dinner pretty early so we're having a snack now to tide us over to the morning. I show him my map and explain that I have renumbered the lines for the second project so that we don't have to say "line one on the second map" just "line twenty-one." He approves and he raves about my map. I'm proud of it myself.


Anonymous said...

Who's not proud of you? Your loved...... enjoy the flight.....


Rhonda said...

The air activated ones are often just fine iron shavings, and in those ones the heat is caused by them rusting.

Anoynmous said...

I wonder if some peroxide in a zip-lock bag with the oxygen-activated type could coerce it into acting like the binary-chemical type.

Either that, or add a cannula to your sneakers?

Frank Lee MeiDere said...

There used to be bags of iron filings that got very, very hot when you shook them a bit. There was no chemical reaction, so they never wore out. I haven't seen them on the market now for a couple of decades, and can't imagine why not. They were so much more efficient than the one-use chemical warmers.

A Squared said...

There was no chemical reaction, so they never wore out.

Not possible. If true everyone would have simple perpetual motion machines, plus the laws of thermodynamics would be invalidated

Ed said...

Actually, A Squared, it would be possible for those things to get warm without a chemical reaction. It could be a nuclear reaction, which would also account for them not being on the market any longer.

More sensibly, aren't there phase-change versions of these which work by melting some wax or salt or something in a oven or microwave before going out in the cold then evolving a non-negligible amount of heat as they solidify again? They're reusable. Similar are used as an alternative to hot water bottles for warming beds. Maybe Trix's aircraft needs some way you can push one of those into the vicinity of the exhaust.

Anoynmous said...

If there indeed were a way to sell bags of heat that never wore out, they probably wouldn't be sold for very long. As soon as everyone had one, nobody would need to buy more.

But the iron filing warmers do wear out, so that doesn't explain why Frank's remembered bags aren't available.

cockney steve said...

Never mind the iron filings, what the heck is a "turtle cheesecake" ?

I have visions of a crispy pastry crust with a cheesecake centre.

Here in UK, you can get little tin handwarmers, ~ 12 x 6 x 1 Cm's which are powered by liquid cigarette-lighter fuel,aka"petrol" they have a catalytic action and are quite toasty ,lasting several hours on a filling. I've never heard of anyone's pants spontaneously combusting as a result of one of these, but I assume that they use atmospheric oxygen,so that doesn't help you either.

love the depth and variety of your blog, it gives a real insight into your part of the world.

coreydotcom said...

@ cockney steve:

I'm guessing "Turtle" as in the brand of chocolate.

They're quite popular here in Canada, mostly around the x-mas holidays (I think) and they are friggin delicious.

So like a chocolate cheesecake, with the chocolate being a "Turtle".

Anonymous said...

I can't understand why an airplane that can fly that high doesn't have a working heater.

With that said maybe a visit to the local motorcycle shop for some electric gloves.

Boots (at Marks) have bats in them that work for up to 7 hours.

A Squared said...

it would be possible for those things to get warm without a chemical reaction. It could be a nuclear reaction,

Well, yes, I suppose, but even these would wear out after a time, which was more what I was disagreeing with than the lack of chemical reaction. As you point out there also are warmers which release heat from a phase change. In any case, none are a perpetual source of energy, and the iron filing warmers *do* involve a chemical reaction.

A Squared said...

I can't understand why an airplane that can fly that high doesn't have a working heater.

Because it's broken.

Aviatrix said...

It's not broken, it just doesn't produce sufficient heat above 16,000' or so. It does seem odd to produce an airplane with a service ceiling almost twice that of its heater. We have theories about relative tropopause height and stuff.

Lee I said...

Lap robes. I think that's what they used to call those blankets in the car (US). The cars had a rope-like thing on back of the front seat to hang the car robe over until it was needed. Those rope things disappeared, well, several decades ago. It finally occurred to me that the invention of the car heater probably made it obsolete.

Dan in ALB said...

What about using a Snuggie? That way you can cover more of your body with the blanket while still having your arms free. Of course, they make winter coats for this purpose too :-)

Aviatrix said...

Oh trust me, I'm already wearing a parka and gloves. The operator laughed when I brought a parka to work in July. At first.

I think a Snuggie would probably hamper emergency egress. You need something that can be thrown aside during an emergency descent without interfering with aircraft control.

A Squared said...

It's not broken, it just doesn't produce sufficient heat above 16,000' or so. It does seem odd to produce an airplane with a service ceiling almost twice that of its heater.

As I mentioned in a previous post, I have flown (I beleive) the same plane, for the same purpose, at the same altitudes. Yes, the heaters are finicky. However, when they are working, they do produce heat above 16,000. Not shorts and flip-flops heat, but not the kind of cold you describe, by any means. If you're bundling up in robes and such, your heater isn't working like it is supposed to and is capable of.