The Second Best Place To Set a Bomb

An airplane I flew today had an oddly located fire extinguisher. While looking up the rules in CARS 525 on where the fire extinguisher has to be with respect to the pilot's duty station, I found some rules on airplane interior design that weren't there when I learned to fly.

(c) An aeroplane with a maximum certificated passenger seating capacity of more than 60 persons or a maximum certificated take-off gross weight of over 100,000 pounds (45,359 Kilograms) must comply with the following:
(amended 2010/06/16; no previous version)

    (1) Least risk bomb location. An aeroplane must be designed with a designated location where a bomb or other explosive device could be placed to best protect flight-critical structures and systems from damage in the case of detonation.

According to this FAA document the Least Risk Bomb Location (LRBL) has been a thing since approximately 1972. The crew should be aware of the LRBL, but we can be forgiven for not knowing, as the guidance document includes a prohibition on marking it with cute international graphics or bilingual block lettering saying something like "place unattended bombs here." For more information on determining the best location of an LRBL, you may consult a document entitled “DHS Recommended Least Risk Bomb Location Procedures for Airlines,” Sensitive Security Information (Limited Distribution). The FAA will need your letterhead and an e-mail address. I hope they do more than glance at the letterhead and go, "ooh, it's embossed, and someone used expensive design software on this, they must be a legit airline. Quick, e-mail them the secret LRBLs." Probably they have more secure procedures than that, but the whole letterhead thing is so quaint that I had to make fun of it.

If you don't have a need to know, or a fancy letterhead, you can still find out about LRBLs. The public document is interesting enough, with little diagrams and recommendations on how the LRBL should work. If you click through to look a the document, don't forget to scroll down to the name of the person responsible for it, and imagine how much fun he has at airports when he's "randomly" selected for special screening based on his name, and then they discover his carry one is full of Sensitive Security Information about where to put bombs on airplanes. Whatever city he lives in, that's where the meetings are.

The airplane I fly does not have a passenger seating capacity of more than 60 persons. Were we to discover a bomb on board, I would direct it to be thrown out the emergency exit. Such a measure would be an extreme emergency procedure for me, but its physically impossible to open an exit on a pressurized aircraft in flight, because the exits are plugs held in place by the pressure. The only way to open one would be to blow it up. The implication of the document is that that's kind of what some LRBLs do. It also points out that decompression is less harmful if it's not done explosively, so I imagine the "oh no there's a bomb on board" procedure involves an emergency descent and controlled depressurization. The descent would be so that by the time the airplane was depressurized and the oxygen in the generators was exhausted, the ambient oxygen would be sufficient to sustain the surviving passengers.

    (2) Survivability of systems:
        (i) Except where impracticable, redundant aeroplane systems necessary for continued safe flight and landing must be physically separated, at a minimum, by an amount equal to a sphere of diameter
        D = 2 v (H0 / P )
        (where H0 is defined under 525.365(e)(2) and D need not exceed 5.05 feet (1.54 metres)). The sphere is applied everywhere within the fuselage limited by the forward bulkhead and the aft bulkhead of the passenger cabin and cargo compartment beyond which, only one-half the sphere is applied.
        (ii) Where compliance with subparagraph (c)(2)(i) of this section is impracticable, other design precautions must be taken to maximize the survivability of those systems.

I think that is meant to imply that if you want to take out redundant systems, you'll need more than one bomb. Plus I'll throw you overboard with your bomb.

    (3) Interior design to facilitate searches. Design features must be incorporated that will deter concealment or promote discovery of weapons, explosives or other objects from a simple inspection in the following areas of the aeroplane cabin:
        (i) Areas above the overhead bins must be designed to prevent objects from being hidden from view in a simple search from the aisle. Designs that prevent concealment of objects with volumes 20 cubic inches and greater satisfy this requirement.
        (ii) Toilets must be designed to prevent the passage of solid objects greater than 2.0 inches in diameter.
        (iii) Life preservers or their storage locations must be designed so that tampering is evident.

What and ruin the plot of so many bad airplane movies? At least there's no rule about disabling the secret passage out of every airplane washroom into the giant avionics bay. I think the life jacket one is interesting. I've never noticed the lifejacket pouches to appear particularly tamper-resistant.

(d) Each chemical oxygen generator or its installation must be designed to be secure from deliberate manipulation by one of the following means:
(effective 2015/03/20)

    (1) by providing effective resistance to tampering,
    (2) by providing an effective combination of resistance to tampering and active tamper-evident features,
    (3) by installation in a location or manner whereby any attempt to access the generator would be immediately obvious, or
    (4) by a combination of approaches specified in (d)(1), (d)(2) and(d)(3) of this section that the Minister finds provides a secure installation.

(e) Exceptions. Aeroplanes used solely to transport cargo only need to meet the requirements of (b)(1), (b)(3) and (c)(2) of this section.
(effective 2015/03/20)

I haven't yet seen a bad airplane movie in which the bad guys repurpose the oxygen generators as poison gas grenades, but maybe it was so awesome I forgot.

Oxygen Exchange

I work in an unpressurized aircraft at altitudes where the atmospheric pressure is low enough that oxygen is required. Between 10,000' and F180 (about 18,000') I wear a nasal cannula: an arrangement of tubes, including two blowing oxygen up my up my nostrils. Above FL180 I wear a mask that covers my nose and mouth. I could skip the cannula and wear the mask any time I was above 10,000' but I can't eat or drink while wearing it, so it gets old fast. Plus the design of the cannula is such that it recycles exhaled oxygen, meaning that the oxygen supply lasts a lot longer on cannulas. Thus we only use the masks if we're working above 18,000'.

Putting the mask on involves taking off my headset, putting the mask over my face, pulling the head strap into place, putting the headset back on, and fastening another mask strap behind my neck. Finally I have to swap the microphone plug for the headset boom mike with the microphone plug for the in-mask mic. I can do all this before take-off, which I will if I'm in busy airspace. I started up next to a military jet once and noticed its pilot put on his oxygen mask before start up. If I am in uncontrolled airspace, I typically put my mask on just before I climb through 10,000'. If I'm expected to be monitoring a frequency, I wait until a needy or slow-talking pilot starts to make a call irrelevant to me, and then I can get the headset off, mask on, and headset back on before the call is over, ensuring I don't miss any calls. It takes less than thirty seconds. On descent, I can use the same technique, or just leave it on until I park, likely confusing the FBO marshallers.

Sometimes the day starts out with an hour of work at at 20,000' and then progresses to three more at 15,000'. Obviously I need the mask for the high level work, but would prefer to be able to eat and drink for the rest of the flight. In this case the swap involves all of the above, plus disconnecting the mask from the oxygen receptacle, connecting the cannula, and putting the cannula in my nostrils. It looks just like the cannulas the patients in House wear, but rather than looping around my ears and hanging down in front, it just goes around my head, held up by my headset earcups, and secured in place with a baseball cap. The point of this post is that I think about perfecting the swap between oxygen supplies at altitude. Should I breathe normally, or hold my breath during the swap?

The way breathing works is that the partial pressure in the air I inhale is greater than that in the lung capillaries it is in contact with. The imbalance causes oxygen to diffuse into the capillary, until the partial pressures are equal, the way any gas does across any membrane. So if the partial pressure in the ambient air is less than that of my lung capillaries, the act of breathing will actually decrease the oxygen level in my blood, and it would be better to hold my breath while I switch between mask and cannula.

The partial pressure of oxygen in ambient air at sea level is 21% of 29.92 inches of mercury, which is 6.28 inches of mercury. I'm going to convert that 160 mm Hg, not because I'm obsessed with metric, but because Wikipedia gives me biological numbers in millimetres of mercury so I have to convert one of them in order to do the math. At 18,000' the partial pressure of oxygen in the ambient air is half that at sea level, so 80 mm Hg. The partial pressure of oxygen in lung capillaries at sea level is 20-40 mm Hg, and as the mask maintains my blood oxygen at the same saturation as at sea level, then that's the partial pressure of oxygen while I'm wearing an oxygen mask. Eighty is clearly greater than forty, so even at 18,000' breathing is better than holding my breath to maximize blood oxygen during the mask swap.

So at what altitude should I hold my breath? At 32,800' the partial pressure of oxygen in the atmosphere is 25% of the sea level pressure, which is 40 mm Hg, the top of the range for lung capillary pressure. I would say, "so up to 32,000 it's better to breathe than hold one's breath when swapping oxygen sources" but above 32,000' the time of useful consciousness without oxygen is around a minute, even with no physical activity, so one shouldn't be messing around with one's oxygen source at such altitudes. But my conclusion is that above that, hold your breath for those few seconds of scrabbling before you either get your oxygen on or forget how and pass out.

I only took biology to about grade eight, so most of what I know about the human cardiovascular system comes from lifeguard class. I welcome any corrections to this analysis, even if you're stopping by years after I wrote it.

Death Rates

I'm IFR in the flight levels on a clear VMC day. The IFR part means I'm following a set of rules and procedures ("Instrument Flight Rules") designed for pilots of aircraft in weather conditions that don't allow them to navigate by looking out the window. The flight levels part means I'm flying above about 18,000'. In Canada the "transition altitude," between altitudes designated by the local air pressure and those altitudes designated by a universal standard pressure setting, is 18,000'. One never flies at 18,000', but instead sets the altimeter to 29.92 and flies at flight level 180. I don't know how our transition level was determined. Our highest mountain is about 19,000', so it wasn't set relative to that. VMC is "Visual Meteorological Conditions," that is weather that permits navigation just by looking out the window.

So why am I IFR in VMC? Because in Canada everyone operating in the flight levels is required to do so under an IFR clearance. It's a safety regulation. I have to fly only as directed and cleared by ATC, in order to ensure separation from all other aircraft. And I'm up this high because this is where I need to work. There's only half as much air pressure up here as at sea level, which means only half as much oxygen per breath, so I'm wearing a mask that provides me with supplemental oxygen. The masks do a great job of that. Testing my blood oxygen level always shows me at 98 or 99% saturation, the same level I get sitting on my chesterfield at home. (The tester looks at my blood by shining a light through my fingernail: it doesn't take a blood sample). Only problem is that in providing a tight seal around my face and being secured to my head underneath my headset, the mask give me no opportunity to eat or drink during the flight. Air before food.

The mask also interferes with the seal between my headset earpieces and my ears, so it's a little noisier with the mask on. Even noisier when my noise cancelling cuts out because my headset batteries died. I'm not sure if the noise cancelling "works harder" to keep up, or if it has the same battery consumption regardless of the ambient noise, and this is just coincidence. I use rechargeable batteries, which when they are new last about fifty hours in the airplane before they die, but after many cycles have shorter lives. I have numbered all my rechargeables and track how long each set (the headset takes two AAs) lasts before it dies. When they can't go a full flight, they get retired to a plastic baggie in my kitchen. Eventually they will go to recycling, when I figure out where to recycle rechargeables. They last pretty well: there are only six batteries in the retirement baggie and I've been using rechargeables in my headset and flashlights for at least eight years.

I change batteries and then notice I'm off my heading. The autopilot has disconnected. I must have hit the button. I reset it and then turn to a new heading, but something doesn't look right. The GPS says I'm going where I want to be, but the heading indicator is way off. I reset it to the compass, and it follows for a while, but soon loses interest again. The heading indicator is powered by two engine driven vacuum pumps, one of which I reported close to needing replacement a few days ago. The suction gauge shows slightly less of a vacuum than ideal, but in the green range and no less than it has for a few weeks. The other part of the instrument shows both vacuum pumps on line. The attitude indicator, powered by the same system, still appears to be working. Legally I'm required to inform ATC of the failure of a heading indicator. I do so, and they seem confused. No, it isn't affecting my operation at all. I'm using an electronic guidance system, and I will be landing at an airport that I'll be able to see sixty kilometres away. I don't need it for the flight. Maybe people don't routinely comply with that regulation anymore.

Before I land, the stupid thing comes back to life. Charming. I'm far from base, but I call maintenance so they can order one, or pull one out of another plane or something for when I come back. They don't have any troubleshooting tips for a zombie heading indicator. It's working now, but it's not reliable, so I snag it. That is, I write in the journey log that it is not operating correctly. This will limit our operations to day VFR (the looking out the window counterpart of IFR) only, which is a huge pain in the neck, because it prevents me from continuing the work above FL180, even though its effect on safety is negligible. I have had transient problems with equipment that never recur, but usually they hint at trouble and then throw a full failure if ignored. I think I've only seen simple heading indicators (as opposed to the more expensive and complex HSI) fail twice before in about 7000 hours of flying. And one was a simple fix, turned out that there was an installation error that had made a screw come loose. I wonder if the suction line is leaking or blocked or something. Nothing I can do about it, anyway.

Cold, Hypoxia and Spiders

From time to time a person stows away in the wheel well of an airliner. There's a big space up there, with room for all the hydraulics, a retracted wheel, and a person. Doors close over the opening to provide streamlining, but I don't know that they close tightly enough to prevent draughts. Mine certainly don't. My gear doors don't even cover the whole opening. There is no pressurization and no heating in that space. At altitude the proportion of oxygen in the air is the same as at sea level, but the total air pressure is less, so the partial pressure of oxygen is also less. This pressure is important. A person can't get sufficient oxygen just by breathing faster. The pressure of the oxygen is what allows oxygen to enter the bloodstream. If the pressure isn't high enough, there is insufficient oxygen for the brain to function. A person loses the ability to make decisions, passes out and if the deprivation is severe enough, eventually dies.

The air temperature decreases by two or three degrees for every thousand feet of altitude, down to about -56C. I've never seen one of these where the stowaway had sufficient knowledge--or resources--to wear a parka. I've been outdoors in temperatures down to about -40. Wearing a parka, and gloves, and a toque underneath my parka hood, and giant Sorel boots, and mittens, while physically active. If I had stopped and curled up for a few hours I know I would have become very very cold.

Most of the time the cold, lack of oxygen and sometimes falling out of the wheelwell kills the stowaway. But sometimes they make it, like this kid from California. Humans can be freaking tough. I find it hilarious, but not that surprising that an unhappy teenager successfully breached airfield security. There is trust involved in aviation. Many places we pay for fuel on the honour system. It takes no genius and rarely requires tools to breech an airport gate. There is also a trade off, mutual assistance among aviators is a tradition much older than airfield security. It's hard to stop people from helping one another. And absolutely any tool someone might need on an airport can literally fly over the fence.

I'm amused that the commenters on that CBC piece include someone who insists a wheelwell monitoring camera and pre-departure check thereof should be standard, someone who doesn't believe the incident happened at all, and someone who sees a conspiracy theory at work.

My airplane often carries little stowaways that seem to suffer no ill effect. Spiders crawl up in my wheel wells. I landed the other day, taxied a short distance off the runway, shut down and got out to clean the windshield. In that time, maybe five minutes since the propellers had stopped spinning, a spider had already strung silk from the propeller across to the fuselage, such that I had to break the web to access my forward cargo area, where the windshield cleaner is. I don't know that it was one of the spiders I carry with me, but I like to think the conditions are producing super spiders. I wonder if insects are attracted to the heat coming off the nacelles, making that a prime spot for web building.

Summer One-Liners

I always scribble notes on my OFPs, but I don't always get time to transform them into blog entries. Here are a few.

This is an oldie that has come back.  Many types of flight require a flight plan, a notification to air traffic control of where and when you want to fly your airplane. You "file" the plan either electronically, or still the old fashioned way by telephone. It's often easier to make a phone call than to get an internet connection. When you call to file a flight plan you start by specifying the call sign, the registration of the aircraft. The specialist can sometimes look up the aircraft in his or her database, removing the need for the pilot to specify the aircraft type, onboard navigational equipment, aircraft colours, and other details that don't change from flight to flight. It's common for the controller to double check that they have the right database entry by saying the type after they find it. There's a flight service joke that I first heard as a student, still stumbling over the required information for the flight plan. The specialist takes the callsign, and then says, "Ah yes, here it is, Boeing 747 on floats."

The correct answer to this is obviously, "Nah we put it on skis over the winter, haven't swapped them back yet." Or perhaps, "Nah that's GOLF Mike Tango Foxtrot. People get us mixed up all the time."

One the flight plan is filed, you need a taxi clearance, permission to drive the airplane on the ground to the runway, or maybe from the parking space to the place you pick up your passengers or buy fuel. Much of the ground may be uncontrolled, not requiring a clearance, but at an unfamiliar airport it is not always clear exactly where the controlled portions of the apron are. One always errs on the side of caution and asks for taxi clearance. Or even if I know it's uncontrolled, I'll usually call and tell the controller, so he or she isn't wondering where this airplane is off to. The controllers are usually happy to give directions on the uncontrolled portion of the airport, to help pilots find a particular hangar. So it's wasn't completely bizarre to hear a ground controller say this to another pilot, just funny.


Ground controller, "If you know where you are going, continue."

Then you take off, and the controllers help you stay clear of other traffic.  You know you're pretty far north on a clear day when you hear the words, "you'll be following a VFR 737" and you're not in the approach phase of the flight. One usually expects aircraft as large as a B737 to fly IFR for most of their trip.

But by the end of the flight on a good day everyone is cancelling IFR to make it easier for others to get descent clearance. Descent for us means a chance to take off our oxygen masks, the context for my final quote, from my co-worker. "Taking off an oxygen mask is like taking off ski boots."

Ahhhh.

Mountain High

I'm filling out an expense report, for reimbursement. The largest item is a product I bought from a company named "Mountain High", in Oregon. I'm going to place it in the hands of a yoga instructor, who will inhale through it. And I thought it was weird expensing cases of beer to pay for northern maintenance.

Mind you, this is an oxygen mask, not actually a joint. And you'd be surprised by the things people who fly airplanes are certified at besides piloting.

I'm Not Even the PRM

As pilot in command of an airplane I have to be assured that all the maintenance is done as both safety and legality require before I take to the skies. When I came on with this company they had a problem with missed maintenance events, so I made them an excel spreadsheet with conditional formatting to colour events close to due in bright alerting colours. Every once in a while a new thing that I should have been tracking but wasn't is unearthed, either because I set up the sheet based on the aircraft manufacturer's intervals and the component manufacturer had a more specific requirement, because the requirements are amended, because I made a false assumption or because I just plain missed something. Today it was determined, I think through researching an STC, that a particular check valve, if it was one of two particular possible models, is due for replacement ten years from the date of manufacture. I pulled off the panel under which the check valve lurked and determined with a flashlight and determined squinting that the part was of one of the specified model numbers, dash four. I don't know if the -4 radically changes the life expectancy of the part. I just relay this information to the AME.

And then I go and do some other things slightly more piloty. Or maybe less. I think it may have involved getting a return authorization for oxygen regulators that were adjusting themselves in flight, leaving two crew members with hypoxia in the first week we used them. We stopped using them after that.

And then back to the check valve. Dash-4 or not it still needs to be replaced ten years after manufacturing, so the AME goes back into the panel, with a flashlight and a mirror, hunting for a date. There's a straight line in the manufacturer's label that has been scratched off. Was that the date. I joke and ask him can't he determine the model year from the colour and styling? We kind of suspect that if this check valve were a Volkswagon Beetle it would have a split windscreen and tiny red tail lights. "I'll order one now," sighs the AME.

And then after I went back to my computer, the ops manager kicked me out for working too long a day.

Alcohol-Based Oxygen Generation

As I descend into the aerodrome environment I position report on the general traffic frequency of 126.7 and then switch to the mandatory frequency for the airfield and make another call. I'm thirty miles out, descending through, I don't know, nine thousand or something. A helicopter pilot calls short final. Not for the runway. Not even for the aerodrome. He's on final for Bear Mountain. Can you be on left base for Bear Mountain? I never know what helicopters are doing, but the pilots tend to be professional and know what they are doing, and they also grasp that we dimwitted fixed wing folk are bedazzled by their whirling wing.

We land, on a runway, not a mountain. We persuade the people there to put fuel in our airplane in exchange for their being able to take an imprint of a piece of plastic our employer gave us. Seems fair. We also need oxygen, but that is not a service the FBO offers. A local operator has oxygen though, and the fueller knows one of the maintenance guys there, so he makes an introduction. They have the oxygen. They have the time. We have the fittings for our non-standard tank. But they aren't set up for selling oxygen. Eventually the service is negotiated in exchange for the northern currency: a case of beer. Honestly if the stuff wasn't so heavy and perishable we'd just carry a couple of cases around at all times. Any favour can be had for beer in the north.

We leave, with our oxygen, and hear that helicopter on final for a different mountain.

The Empire Will Be Pleased

The title is what my coworker said through his Darth Vader oxygen mask as we descended from the flight levels in an unpressurized airplane after completing a tricky piece of work. We descended overhead Banff, Alberta. It is so spectacularly beautiful there that I was distracted from the work I was supposed to be doing. I was even raving about the remarkable pointiness and ridginess and beauty of the scenery to the air traffic controller. The air traffic controller was meanwhile excited by the fact that I could still talk to him. We went from the flight levels to dodging in and out of those spectacular stripey peaks and we still had excellent two way radio communications. And then we landed at Springbank. Springbank is the Buttonville of Alberta. Screaming busy with training traffic, and controllers who tell you what you want instead of listening to what you requested. The best was the one who gave me an instruction to turn right, and then chewed me out for deviating from the straight out departure clearance I had been given. Such a startling contrast from the service I got from the very next controller they handed me off to. I cannot turn right and go straight at the same time, although with some of the aerial work I do it almost seems that way. If you have the opportunity, you should go to Banff and fly around at about 11,000' in the spring. I think you should put it on your bucket list. I'm a not a stranger to mountains, Banff just seems to have especially amazing ones.

What Do You Mean, One Way?

All the BC work was done in one fell swoop, and just as well because it's cloudy the next day. I'm flying back to Alberta via a little airport in the north where we have an assignment. It will be an IFR flight to the area and then VFR work in the area, so I must file a composite flight plan, a combination of IFR and VFR. This is allowed for in Canada, because flights leave urban areas IFR then continue VFR to remote destinations or even more needed the reverse, where an aircraft departs a northern area VFR, maybe on amphibious floats off a lake, then flies south to where radar coverage begins, climbs onto an airway and picks up an IFR clearance into a urban area. The box for flight plan type allows four choices: V, I, Y or Z. V is for VFR, I is for IFR and the other two are for composite plans. If the first leg is IFR, the composite plan is a Y, and if the first leg is VFR, the composite plan is a Z. You can switch back and forth more than once during a flight, but the letter still designates the first leg. I remember this because if the legs IFR, VFR are in alphabetical order, then you get the first letter, Y, but if they are in reverse alphabetical (V then I) then you file the last letter of the alphabet, Z. Not terribly clever, but if you have an operational need for composite flight plans it can save you looking it up again.

I filed out eastbound on V304, the closest to going in my direction and then when I ran out of airways pointing in the direction of my destination, and the terrain got a little lower, direct the destination. I picked up my departure clearance, but then before I taxied out ground called back and said that IFR flight planning wanted to talk to me. I have, apparently, filed eastbound on a one-way airway. Weird. I don't remember those from any part of my flight training. There is nothing I saw on the chart on the chart to indicate that it is westbound only. I ask the IFR flight planning guy, who reroutes me around to the south, how I should have known. He says I should have consulted the preferred routes in the CFS.

Now that makes no sense. If I am going between two centres that get a lot of traffic, or if I'm generally going in the direction someone on such a trip would take, I consult the preferred routes. But there isn't even an airway going to or in the direction of my destination. You'd have to be psychic to divine that V304 was not for use of eastbound traffic just from the fact that it wasn't the preferred route to Calgary or Edmonton. I accept my amended, detouring clearance and depart as advised, accepting vectors all over the place before finally being cleared direct to "maintain one fife tousand while in controlled airspace." You have to read back the "while in controlled airspace" part too, I guess to acknowledge that you are heading out into the great green beyond. (Canadian IFR charts colour regions of uncontrolled airspace green on the charts).

I have two radios on board, but one of them I have been advised not to transmit on, because ATC always complains about the readability. I monitor ATIS on that radio, or monitor the current ATC frequency when I'm using the talking radio to call flight services for something. Every once in a while, maybe two or three times in twenty flights, the receive button for COM1, the listening-only radio, somehow gets activated and I'll be listening to whatever ATIS or other frequency I have up there. I try to unpress the receive button for COM1 but it won't work and I have to reactivate COM2 in order to get it to go away. I guess I must be reaching for something and hitting the wrong button, but I'm never conscious of having done it. Maybe it's because I'm wearing gloves against the cold.

We climb up to altitude and level off over the clouds. I trim out the airplane, set the power up for cruise and finish off the rest of my cruise checks, then get really decadent and put on the autopilot. The autopilot is good not just for giving me a rest from flying, but for freeing up my mind and hands to do other checks. I pull out my pulse oximeter and clip it on the end of my finger. It freaks some people out the first time I offer it, because they assume something that will check their blood oxygen level is going to take their blood, and they don't want to put their finger inside. But it just shines a light through your fingernail and looks at the colour. The problem is that right now it's reading an oxygen saturation level of 79% for me, and that's not right. I have the operator reset my connection to the system and I'm quickly back up into the nineties where I should be. You really can't tell when you're hypoxic until your visions starts to go. It's worse than being drunk, where you usually have a clue. Like being drunk, even if you do notice, you lose the ability to make good decisions about it. As the oxygen mask manual explains, you may decide that you always wanted blue fingernails.

We clear the last of the mountains and reach the Alberta area where we have work to do. I say the magic words "cancelling IFR" and then we're left alone to fly lines under visual flight rules. The operator says the camera is fine, despite our transit through clouds. I don't know why sometimes a single wisp is a threat and at other times half an hour of solid IMC isn't. Maybe it depends on his level of hypoxia. We fly back and forth in really straight lines until that project area has been completely photographed, and I land at a little airport where we can get the fuel pump activation code by giving a credit card number over the phone. We fill up there and I file another flight plan for some higher altitude work. The heater works, but we hardly need it today, both because it's significantly warmer (yay!) and because we're shut down by the daytime cumulus we call popcorn clouds, for their ability to suddenly pop up and cover the area in white spots.

We're right overhead where he wants to land, so I do a shuttle descent, back and forth with tight turns on the ends, like the weft in a loom, because shuttle is named for the instrument a weaver uses to send the weft back and forth through the threads of the warp, to make cloth. Vehicles that go back and forth--be it from the hotel to the airport or from the airport to outer space--are called "shuttles" after the weaver's back and forth shuttle, but the etymology goes full circle because the name of the weaver's shuttle derives from the Old English scytel "a dart, arrow," and from the same root as shoot. The back and forth motion and the turning and the heat makes the operator sick. I feel badly because another human being is miserable, partly attributable to what I am doing, but there is nothing really that I can do, except put the airplane safely on the ground.

Once there, we park at the fuel pumps and then become the centre of attention from two pilots in a King Air 200. They are on one of those missions where you fly your people somewhere and you wait patiently and they are bored enough that two people they haven't met yet is a fascinating diversion. We all share a cab, us to our hotel and them to a café nearby. The cab driver delights in showing us the spot where a drunk driver went off the road at 150 km/h or so. You take your excitement where you can in a small town.

We go shopping and can't find sick bags available, so we improvise with plastic freezer bags tucked into brown paper lunch bags. Tomorrow's mission is in airspace that I'm told we have permission to operate in, but it's marked on the charts as military restricted airspace Monday to Saturday, with hours, other times by NOTAM. I call the number listed in the Designated Airspace Handbook for the controlling agency, and speak to a very polite but unambiguous and emphatic young man who absolutely cannot give me permission to operate there. He's forceful, but not in the least rude. Even as I am frustrated, I am admiring. The Canadian military has taught him this, and this is exactly the way I like to think my country's soldiers are enforcing the rules wherever they are deployed. If you can be this verbally clear without being demeaning, then nobody needs to get shot, but it's also perfectly clear that while this young man lacks the authority to give me permission to cross the line, he does not lack the firepower to stop me from crossing it by any means necessary.

Clipboard security woman, if you remember her from last year, could really use the training this man has received. And I don't just mean that she should be made to take off her silly shoes and march around in the heat or cold for days carrying heavy objects, although I'd be happy to know she was subjected to that, too. She would greatly benefit from training in giving clear definite prohibitions while being perfectly polite and respectful. I would be happy to be that good at it as a captain. I thank the soldier and ask him how I can get in touch with someone who has the authority to give that permission. I have to call back in the morning to get someone. So I will.

---

I'm not going to mention shuttles for nothing. Did you see this picture showing the same father and son watching the first and last space shuttle launches? It's a little daunting to realize that I've lived through the whole era of the space shuttle. What's next?

Good Thing We Weren't in Outer Space

I check the oxygen equipment and set up the oxygen bottle so I can reach the valve from my seat. The oxygen bottle has its own nylon pouch, which protects it from getting scratched or getting dirt in the valve, and the pouch has pockets for the instructions and accessories and straps for carrying it, so it's easy to secure the whole thing so it can't ricochet through the cabin in turbulence. Sometimes you just have a naked oxygen bottle and those are hard to confidently secure. I've also seen pilots just stick the whole thing in a seatback pocket, as if to say, "so long as I have oxygen it doesn't matter if I'm struck in the back of the head by a heavy object."

I run up the airplane. The altitude makes the engines run very rich. Once I am lined up on the runway, I even lean it a little for the take-off, just enough for it to run smoothly. The takeoff now seems to take forever in the thin, high altitude air. The afternoon is going to be hotter and make the air even thinner. That's why the runways are so long out here.

Climbing through 10,000' I try to turn the valve on, but I can't quite get it to work, damnit. I have to get the mission specialist to get it for me. I should have just left it on and controlled it from the little valve on the canula. I adjust that little valve now so the tiny indicator ball lines up with the gradation matching my altitude. I'm sucking oxygen through my nose, but it's hard to tell if it's working, because oxygen is odorless. I check my blood oxygen with a clip on meter.

The heat of the day drives cumulus development again. The same line of thunderstorms probably forms every day. The thunderheads don't seem as high as they do in the Canadian prairies, even though the tropopause is higher, so they are probably higher. I suppose it's because we are higher already, so there isn't as much vertical volume for them to build in. Below us are dry fields. I see something that the mission specialist says is a coal mine. It's an open mine, not the underground kind that they have in West Virginia, hence the lack of tragic news stories associated with midwest mining, the way there are in the east. That was a lazily constructed sentence, but I'm not fixing it, so there.

As I come in to land, I know what is going to happen and I work to compensate, but not quite enough to get it perfect. Although I am flying at the correct indicated airspeed into a very light wind, the countryside is racing by as if I had a horrific tailwind. The air is so thin that I need to go faster over the ground in order to fly through air at the same rate. It's like if you play the same Pac-Man game on a giant monitor, the little yellow guy seems to go twice as fast, even though he's getting the same number of dots. The illusion that I'm going fast makes me think I have more energy than I do. I should have done just a little flare and let the high groundspeed come off on the rollout, but instead I try to land just a touch too slowly and the touchdown is firm. "Sorry," I say, "Getting used to the altitude."

"We were going faster than usual, weren't we," says my critic from the back. Actually, I explain, we were going a touch slower than usual; it just looked faster, which is why I went too slowly and why it wasn't that great. He says he was looking at the GPS and it was faster. I'm not sure he believed my, "Faster groundspeed, yes, but slower airspeed," explanation. Next time how about I just not screw up.

The oxygen gauge is just on the edge of the red. I take the bottle and get in the passenger seat of the other mission specialist's truck to go to get an oxygen fill at the next airport over, while the afternoon pilot fuels and otherwise prepares for the next flight. It's about a twenty minute drive to the bigger airport. It has a couple of different names, because it's a regional airport as well as a local one, but it's well-signed and we find the FBO right away. I've used an FBO of this franchise before in another state. The customer waits outside in the air conditioned car, listening to satellite radio, while I go in with the oxygen bottle. There's another customer at the counter, so I wait and then make my request.

"Oh, sorry," she tells me cheerfully. "The A&P is the only one qualified to use the oxygen equipment and he goes home at one."

To be perfectly fair, when I called yesterday I asked if they provided oxygen service and then asked immediately what their hours were. I didn't specifically ask whether oxygen service was provided throughout their opening hours. But I think that was implied strongly enough that I have a right to be ticked. Rather than making her defuse an annoyed would-be customer I make her expend the same energy more usefully. Her place of business-- whether it was her or not on the phone last night I can't say--implied that I could get oxygen here yesterday, so she is going to figure out where I can get oxygen. I ask her to where I can get an oxygen fill on a Sunday, to call and confirm that I can really get O2 there, and when she doesn't get an answer at first, to see if she can call out the one guy who knows how to use the oxygen equipment, for a fee. She finds someone at the next airport along the road that is there and can fill the bottle. It's another forty-five minutes drive or so and then we have to come back with it. I thank her and get back in the truck to break the bad news.

It's not a bad drive, really. Air conditioned truck, compatible taste in music, fences, bluffs, cattle, authentic western scenery. Someone I know was going to be driving a motorhome up here, all the way from Indiana this month. If you pretend you came some place for a vacation you can usually make it into a fun adventure, and if it's so bad you couldn't imagine going there on purpose, you can at least thank your lucky stars you're not stupid enough to have gone there without being paid. We eventually get to the proper airport and find the FBO, which appears to be named "FBO." A flight instructor takes the bottle and looks at me strangely when I say that the previous airport said only the A&P could do it. Clearly he doesn't think this is a technical job. He brings it back. The gauge reads full. Presumably it will keep our sats up rather than making us talk in a squeaky voice. I pay for it and then get back in the truck for the long drive back.

There's an air conditioned pilot lounge at the airport, so my colleagues isn't baking out there on the ramp. The mission specialist drops me back at the hotel and then he goes flying.

Some idiot is buzzing the town in the evening while I'm trying to sleep. Over and over again. He's doing circuits, I guess what he as an American would call "staying in the pattern," but he's clearly not climbing out at an optimal rate after each takeoff. If I knew where you slept, bozo, I would buzz it at six tomorrow morning.