Canadian ATC Strike Tomorrow

Posted on July 19, 2005 by David Megginson

[Update: tentative settlement.]

The Canadian Air Traffic Controller Control Association (CATCA) has served notice of strike action beginning tomorrow, Wednesday 20 July 2005. As far as I can tell from reading the CATCA bulletins, there is no intention of withdrawing air traffic services; instead, the controllers seem to plan to stop training new, unlicensed controllers.

That sounds like a reasonable action. It puts pressure on Nav Canada without stranding millions of summer travellers, though it may be that CATCA (local 5454 of the Canadian Auto Workers) does not have the legal right to stop providing services anyway — I don’t know the background. I’ll just keep my fingers crossed that Nav Canada management does not react by doing something stupid like locking the controllers out. Hopefully, if the controllers are not allowed to withdraw air traffic services, then management is not allowed to lock them out either.

Update: Friday 22 July

Aviation.ca reports that the union and Nav Canada have reached a tentative settlement, after the union postponed the strike action for a couple of days.

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Starting

Posted on July 19, 2005 by David Megginson

There are two points in a flight when people outside the plane tend to watch and critique you: when you start the engine, and when you land.

Granted, unless you’re hand-propping, a starting error is much less dangerous than a landing error; however, failed starts happen far more often, and there’s nothing like the grating “chuff-chuff-chuff-chuff” of a failed start to make all the airport old guys look over and shak their heads in dismay.

Aviatrix has just posted two articles on starting carbureted piston engines, here and here, and they’ve generated a good number of interesting comments. Read them, if you haven’t done so already.

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Float Planes, redux

Posted on July 18, 2005 by David Megginson

A short while ago, I wrote about the problem with float planes — the fact that there’s normally no way to get out when they flip upside down or sink — and about the war of words between the Canadian Transportation Safety Board (who want an airworthiness directive requiring the installing of escape hatches) and Transport Canada (who claim they are unable to issue one, since many of the type certificates are not Canadian).

This morning, unfortunately, we saw another example of the problem here in Ottawa on Constance Lake, which has a floatplane base and a floatplane training facility. A Cessna 185 flown by a very experienced pilot flipped upside down in gusty winds and, presumably, the cabin filled with water. The plane didn’t sink, though, and there were people at the scene right away trying to help. They dove repeatedly trying to free the pilot, but for 20 minutes they were unable to open a door or window to get at him — fortunately, there was a fire department near by, and firefighters were able to cut the pilot out. At the time of posting, he was in critical condition in hospital, after having CPR performed on him at the scene.

I hope there’s some legal way to order — or at least to allow — modifications on float-planes to add a quick-release belly escape hatch.

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The alpha-beta of flying

Posted on July 18, 2005 by David Megginson

Here’s some flying Greek from a flying geek:

α alpha Angle of attack The vertical angle between the oncoming air and the zero-lift line of the wing, as shown (partly and imperfectly) by the airspeed indicator.
β beta Sideslip The horizontal angle between the oncoming air and the aerodynamic centreline of the aircraft, as indicated (partly) by the inclinometer (the ball in the turn coordinator).
γ gamma Flight path angle Angle of the flight relative to the earth. When you fly an ILS approach, you’re following a constant gamma angle, even if your alpha and THETA vary.
Γ GAMMA Geometric dihedral angle. Vertical angle of the wings as they extend away from the fuselage. Normally the wing tips are higher than the roots, to improve roll damping, especially on low-wing planes.
δ delta Control surface deflection angle I.e. CLδe is the contribution of elevator deflection to the coefficient of lift. In a plane with direct control linkage (rods or cables), you could theoretically determine control surface deflections directly from the position of the yoke and/or rudder pedals.
ε epsilon Downwash angle The most important example is the angle of the downwash from the wings hitting the horizontal stabilizer.
θ THETA Pitch angle The aircraft’s rotation in the pitch axis, as read off the attitude indicator.
Λ LAMBDA Sweep angle Horizontal angle of the wings relative to a line perpendicular to the aircraft centreline (does that even make sense)? LAMBDA is usually close to zero on slower planes — sweep doesn’t do much until you get transsonic.
ϖ pi ~3.14 You were expecting, maybe, chopped liver?
ρ rho Air density As in 0.5ρv2 in the dynamic pressure equation you had to memorize in ground school.
σ sigma Sidewash angle The horizontal angle of air deflected to hit a surface of the plane (think of downwash, and it might make sense — I cannot think of a good example, though).
Φ PHI Airplane bank angle Rotation in the roll axis, as read off the attitude indicator.
Ψ PSI Airplane heading angle Rotation in the yaw axis, as read off the compass.

(I hope that the Greek characters show up in your browser.)

This is only a selection — if you want more (much more), grab a used copy of Jan Roskam’s Airplane Flight Dynamics and Automatic Flight Controls, part one, which I used as a reference for this list.

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Aviation Blogs Update

Posted on July 17, 2005 by David Megginson

The aviation blogosphere is getting big, or at least, I’m finally starting to find the other bloggers, especially beyond the typical student-pilot blog. I’m doing an update to add some more blogs to my blogroll, copying them over from my subscription list on Bloglines. I’ve already posted about most of the blogs that were previously on the roll; here are the new ones, in alphabetical order:

Aviation.ca News
News releases, accident reports, etc. for Canadian aviation. If you fly in Canada, you need to subscribe; if you don’t, then you probably shouldn’t bother. I use the RSS feed to keep up to date on NavCanada strike talks, runway closures, etc.
Blogging at FL250
A weblog by a junior pilot at a regional airline (flight level 250 is a typical level for a commuter turboprop, above the piston planes but below the jets). This is a nice complement to the other professional pilot blogs in my roll, ranging from young commercial pilots looking for their first break out of charter/freight-dogging, to an older commercial pilot quite happy to freight dog, to an older airliner pilot breaking in young copilots in the right seat. Start with this posting about a death of a fellow pilot, which might make you cry.
Corrosion of the Week
Aviatrix put me on to this one. The author doesn’t actually manage to post every week or even every month, but when she does, it’s usually pretty interesting. Corrosion is a huge deal for owners — it haunts our dreams — but probably not for renters or professional pilots (since someone else will pay for the repairs anyway). Subscribe accordingly.
Freight Dog Tales
An older (over 40) pilot who switched mid-life to flying freight in a Caravan in California. Fascinating stuff, especially since it has the calm, mature perspective of someone who is happy with where he is and what he’s doing, rather than waiting for the call from the airlines. This is a good read for anyone who loves flying for flying’s sake.
My Flying Blog
A blog by another owner-pilot (like me), a breed underrepresented in the aviation blogosphere. The author is currently in the middle of a trip from the U.S. midwest to Alaska, and is posting many pictures and stories.
Rant Air — Welcome Aboard!!
Here’s a blog from someone on yet another step of the career ladder — in this case, right seat on a 737.
Undefined Value: Kris Johnson’s Blog
I figured I needed at least one student-pilot blog on the roll. A few of us have followed Kris through his first solo and a mind-numbing amount of money (even by aviation standards), which he kindly lists in every post. Note to self: cannot afford training near Atlanta.

Enjoy!

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Low wings and the flare

Posted on July 15, 2005 by David Megginson

Very often, I see people write that low-wing planes like my Piper Warrior have a longer flare (i.e. they float longer) than high-wing planes like the Cessna 172, usually based on the argument that lower wings benefit more from ground effect.

In fact, that does not seem to be the case: the numbers in the POH all indicate that the Warrior actually has a slightly shorter flare and shorter landing distance than the 172. My own personal experience is more dramatic: I find that the Warrior’s flare decays very rapidly at the end compared to that of the 172, and it took me a while to learn to land the plane smoothly without dropping a foot or two at the end. Other Piper owners have reported similar experiences, though, obviously, the differences are much smaller than going from either the Warrior or the 172 to a more heavily wing-loaded plane like the 182. The condition and rigging of any individual plane will also make a huge difference — if someone is flying battered, badly-rigged 172s and then switches to a clean, well-rigged Warrior, the Warrior will certainly flare better.

So what’s going on? Why would a plane with lower wings and about the same gross weight float less, when the wings are closer to the ground and should benefit more from ground effect? Here are two possibilities:

  1. The Warrior has a wing loading of 14.4 lb/ft^2, vs 13.8 lb/ft^2 for the 172P. That’s not a huge difference, but it will affect the plane’s floating ability. By comparison, the Cessna 182P has a wing loading of 16.9 lb/ft^2 (note that all of these apply at maximum gross weight, not with just one or two people on board).
  2. The Warrior’s wings have a lot more dihedral than the 172’s wings. Low-wing planes need more dihedral to get the same roll stability as high-wing planes, and the dihedral creates a lot of drag, as well as putting the wing tips (though not the roots) fairly high off the ground. Both the dihedral on the Warrior and the wing struts on the 172 cause drag, but I suspect that the struts produce only parasite drag, which is fairly constant, while the Warrior’s dihedral affects induced drag, which can increase dramatically near the stall (hence the abrupt end to a Warrior’s landing flare).

Basically, these two factors overwhelm any benefit gained from ground effect, increasing the Warrior’s stall speed and decreasing its flare and landing distance compared to the 172, as can be verified by the numbers in the POH. With no flaps, the 172P stalls at 51 kcas (44 kias), while the Warrior stalls at 56 kcas (50 kias); with full flaps, the 172P (with its huge fowler flaps) stalls at 40 kcas (33 kias), while the Warrior stalls at 50 kcas (44 kias) — since both planes have the same approach speed, a higher stall speed means a shorter flare.

As a final confirmation, the published landing distance over a 50 ft obstacle at sea level/ISA/maximum gross weight is about 50 ft longer for a 172P than a Warrior.

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Renewed

Posted on July 14, 2005 by David Megginson

I flew my 24-month renewal IFR flight test on Wednesday morning. It was a very different experience from my PPL flight test in 2002 and my initial IFR flight test in 2003. Back then, I had been in nearly constant training (PPL, night rating, IFR) and had many more dual than solo hours in my logbook — I was drilled up to my eyeballs in procedures, and probably recited them in my sleep. Now I’ve had two years of real flying to pick up bad habits and forget all the little things teachers like to see (like doing a weight and balance even when you’re flying alone 500lb under gross), so I was quite nervous; moreover, I haven’t flown a hold for real since I got my rating.

I was nervous for nothing. The examiner, a 20,000+ hour instructor who’s seen and survived every stupid thing a student could possibly do, threw me a curveball in the ground part with an unusual lost-comms question (lost comms at the start of an IFR training flight in low IMC, where I’d filed for a hold and several approaches) where there was no single, correct textbook answer, so I just ran through the options and said what I’d do in real life, basing it on the rule of least surprise for ATC. I must have bored the poor man almost out of his mind in the plane before takeoff, running through every possible post-startup check in slow motion and excruciating detail as if I were a 50-hour student pilot (“now I’m verifying the ADF ident on the terminal chart; now I’m swerving left to see if the needle tracks; now I’m turning on the pitot heat and looking for a jump on the ammeter … excuse me, are you still awake?”). In real life, I can get my plane rolling quickly, safely, and efficiently, but exams aren’t real life, and this wasn’t the day for a 30-second runup.

I flew my original IFR flight test two years ago in IMC with 400 foot ceilings. This time, I was in VMC under foggles, but a squall line had just passed through and there were small cells all over the place in its wake — I flew into a tiny wake cell like that last summer and never want to repeat the experience. The examiner was watching closely outside the window to keep us away from the darkest stuff, ATC was vectoring us all over the place, and I was keeping the stormscope in my scan, but we all knew what we were doing and the flight and procedures all went calmly, smoothly, and (dare I say it) professionally.

I used to wonder how airline pilots could stand the stress of checkrides and fear of failure every few months, but I think I get the idea. Two years ago, I was being tested on what I had just learned and barely practiced; this time, I was being tested on what I do every week or two and can handle almost by reflex. I didn’t fly perfectly by any measure, but I flew a bit better than I normally do, and that was a nice feeling. Hopefully, when my next IFR renewal exam comes two years from now, I won’t worry as much beforehand.

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Approach Ban

Posted on July 12, 2005 by David Megginson

The weather at the airport is reported below minima — is it legal to try the approach anyway, just to take a look, before heading to your alternate? This is one area where the rules in Canada and the U.S. seem to differ quite a bit.

In the U.S., aircraft operating under FAR Part 91 (private and some commercial operations) have no restriction at all: they are free to try an approach even if the weather is reported as 0 ceiling and visibility. U.S. aircraft operating under FAR Part 135 (charter and commuter, sort-of) are not allowed even to attempt an approach unless the weather is at or above minima. This is probably a gross oversimplification, but it gets the rough idea across.

Canada falls somewhere in between these two extremes. We have something called the Approach Ban, laying in out gory detail when the pilot of any flight (private or commercial) is allow to attempt an approach based on Runway Visual Range (RVR) reports from transmissometers located at the runway threshold (RVR “A”) and mid-runway (RVR “B”):

  • When only RVR “A” or RVR “B” is available for the approach runway, it must be reporting at least 1,200 ft.
  • When RVR “A” and RVR “B” are available for the approach runway, RVR “A” must be reporting at least 1,200 ft, and RVR “B” must be reporting at least 600 feet for fix-wing aircraft (any value is OK for rotorcraft).

If these conditions are not met, then an aircraft is not allowed to complete an approach past the outer marker or final approach fix. There are a whole bunch of exceptions, though:

  1. if the aircraft is already inside the OM or FAF inbound when it receives the report, it may continue;
  2. if the aircraft has informed ATC that it is on a training flight and plans to go missed, it may continue;
  3. if the RVR is fluctuating above and below, and the reported airport visibility is at least 1/4 SM, the aircraft may continue; and
  4. if the aircraft is conducting a CAT III approach, it may continue.

Even more importantly, the ban applies only to airports operating transmissometers on the approach runway — if you’re flying into a medium or small airport, or even approaching a smaller runway at a big airport, there are usually no transmissometers, and therefore, no approach ban.

That said, as far as I understand (never having sat through commercial ground school), commercial operations all have Transport-Canada-approved operating manuals that can place additional restrictions on what pilots flying for the operator are allowed to do, and these may go far beyond the approach ban (especially since they’re usually ammended after every an accident or incident).

Corrections and elaborations are welcome in the comments, especially from pilots who have sat through commercial groundschool on either side of the border.

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How airshows hurt aviation

Posted on July 11, 2005 by David Megginson

It’s airshow season, and (unfortunately but predictably) the fatalities have begun, with three pilots dead and one missing in two separate incidents over the weekend: a midair collision at an airshow, and a midair collision practicing for an airshow. It’s a sad start to the season, and like everyone reading this blog, I feel for the families and friends of the dead and respect the skill and dedication they brought to their jobs. That said, there will probably be more deaths before airshow season ends, as there are every year: all that I dare hope is that this doesn’t end up being one of those years when airshow spectators die as well.

After World War I, itinerant airshows travelled across Canada, featuring former military fliers who would perform breathtaking stunts at fairs and other public gatherings, and, of course, frequently crash and die. At the same time, however, other fliers were trying to build aviation as an industry, working hard to convince the public that flying was a safe and reliable way to move people and goods. Unfortunately, the fact that the public kept seeing stunt pilots die in fiery crashes worked directly against that goal, and in the end, it was the aviation industry itself that begged for government regulation (similar to that of marine or rail travel) to reassure the public, and got it only after years of intense lobbying. That’s a strange thought now, as we cuss and groan about Transport Canada up here, or the FAA down in the U.S.

Often, the aviation media refers to airshow performers as aviation’s ambassadors to the public — if so, they’re just about the worst ambassadors we could pick, not because they’re bad people (I imagine I’d value most of them as friends, and they’re far more skilled and dedicated than I can ever dream of being) but because they’re doing the wrong thing. If we want to reassure the public about aviation, the last thing we want to show them is people flying close to other planes and the ground, in dangerous attitudes, near built-up areas and in front of large crowds. How are we going to convince the people of downtown Toronto (for example) that small planes landing at City Centre pose no danger when they see airshow crashes — which almost always happen on camera — played over and over on the TV news?

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IFR Training in Canada

Posted on July 9, 2005 by David Megginson

Doug Robertson in Calgary is about to start training for his instrument rating, and has mentioned that there are few online resources specifically about IFR training in Canada. Obviously, though, there are a lot of American resources. Here are some of the differences between Canadian and U.S. IFR training, based on my own experience in Canada and many conversations with U.S. pilots:

  • Partial-panel work is heavily emphasized in the U.S., and forms part of the IFR checkride, where there is often (always?) a partial-panel approach as part of the test. In Canada, you might do a bit of partial-panel work on the sim or in your plane, but it is not automatically part of the flight test (though the examiner can simulate some kind of a failure), and you are very unlikely to be asked to do a partial-panel approach.

  • Recovery from an unusual attitude under the hood is part of the U.S. IFR flight test, but not part of the test in Canada.

  • In the U.S., NDB training is something that usually happens during IFR training and is then abandoned; in Canada, NDB is still a practical, day-to-day part of life, especially if you have to fly up north, so people seem to get less stressed about it, and thus, have a lot fewer problems with it (an NDB hold can actually be easier than a VOR hold).

  • The Canadian IFR flight test is almost unbelievably short. The in-air portion involves mainly tracking a radial from a navaid, performing one hold, and flying two approaches, one of which must be a precision approach for your first test (the second one is usually your return home). Other stuff, like showing an ability to accept clearances and talk to ATC, happens automatically during the test. You might spend more time checking your radios and taxiing than you will actually flying. There’s also an oral portion before the flight, as in the U.S.

  • On the other hand, you have to retake the IFR flight test every two years, while the U.S. test is valid for life.

Once you’ve passed, note also that the 6/6 rule (six approaches in the last six months to stay current) becomes in Canada the 6/6/6 rule (six approachs and six hours real or simulated IMC in the last six months). However, your flight test makes you current for a year, so you’ll have to worry about the 6/6/6 only every second year.

One other nice point about the Canadian test is that, since there’s no requirement for partial panel or unusual-attitude recovery, you can take the test in actual IMC. I managed to schedule my first test two years ago for a nice, foggy morning with 400 foot ceilings and silky-smooth air, and I ended up not having to wear the foggles (which I hate almost as much as the hood).

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