I use my Outside Air Temperature (OAT) probe as an early ice detector, since thinner surfaces collect ice before fatter ones (like a wing). Here’s what I saw:

I immediately climbed higher, even though the air was colder (-12°c), because I knew that the sunlight would cause the ice to sublimate, passing straight from frozen to vapour without ever thawing. These pictures show what happened over the next half hour:

Sublimation is much slower than thawing, so if you have the choice to descend into warmer air, do it. When there’s just a trace, though, and you can get safely above the clouds, sublimation isn’t a bad option.

On a typical VFR summer day in southern Canada or the northern US — the kind that the weather(wo)men call “a mixture of sun and cloud” with a decent amount of humidity — swirling columns of heated air, called thermals, start rising in the morning, and get higher and higher into the late afternoon as the sun warms the ground.

Clouds are the dividing line

At the top of those thermal columns, like scoops of ice cream on top of invisible cones, scattered cumulus clouds form. At first, those clouds might be only 1,000 feet thick and maybe 2,000 ft above the ground, but as the columns rise, the clouds get both higher and thicker, and some of them may develop into storm clouds during the afternoon (giving your typical cottage thunderstorm or 20-minute shower).

Underneath those clouds the horizontal winds are weaker, but the vertical motion of the thermals can cause a lot of turbulence — while the air may be smooth at breakfast, by early afternoon it can be rough enough to have passengers grabbing for the vomit bags, while the pilot feels like he or she is in a wrestling match with the yoke and rudder pedals.

Above the clouds, the air is normally smooth, but the winds are much stronger.

So where do you fly?

Flying eastbound

Eastbound, the best place to be is above the clouds if you (and your plane) can manage it. Prevailing summer upper winds in this part of the world are from the west or southwest, so on a good summer’s early afternoon you can get a 25-30 knot tailwind and smooth air at 9,500 ft eastbound. What’s not to love?

The problem is that the tops of those cumulus clouds keep getting higher and higher until almost supper time. In Canada, you need oxygen to fly above 10,000 ft for more than 30 minutes, and the tops of summer cumulus clouds could hit that height anywhere between 11:00 am and 2:00 pm, even ignoring isolated storm clouds. As the day goes on, without oxygen and a powerful plane, you hit a point that you can’t outclimb the clouds any more, and you’re forced to descend either into them (IFR) or under them (VFR), giving up some of the tailwind, and throwing you and your passengers back into the turbulence.

The good news is that, with the extra speed from the tailwind, you might be able to finish your trip before that happens. It’s possible to fly a Piper Warrior from Ottawa to Charlottetown in well under four hours with a good tailwind, so you can leave early in the morning, fly non-stop, and land for lunch before the clouds (and turbulence) outclimb you. Your passengers will have to put up with a bumpy descent and landing, but the rest of the flight will be smooth.

Flying westbound

Flying westbound, into the wind, you’re faced with a lose-lose proposition:

1. Fly below the clouds to get weaker headwinds, but subject your passengers to stomach-emptying turbulence as the day goes on.
2. Fly above the clouds to get smooth air, and watch your airspeed drop to (or below) automobile speeds.

First thing in the morning, you have a good chance to find both smooth air and weak headwinds at low altitudes (e.g. 2,500 ft), but that won’t last until lunch. As the cumulus clouds start to form, you’ll have to pick sides, diving down into the turbulence or climbing up into the headwinds. And to throw extra salt into your wounds, the headwinds slow you down and make it more likely that you’ll have to make a fuel stop, slowing you down even more, and pushing your flight later and later into the afternoon and the worst of the turbulence and/or headwinds. If you do decide to go above, even that won’t last: in a low-end plane without oxygen, you’ll eventually have to go down below and start banging your passengers’ (and your) heads against the ceiling of your plane.

Flying north- or southbound

In Canada, it’s safe to say that most cross-country flying is on the east-west axis, since Canadian cities are spread out in a thin line along the US border. In the US, on the other hand, you’re just as likely to be flying on the north-south axis (or something in-between). In that case, if the upper winds are from the southwest (typical in summer, at least east of the Rockies), then flying southbound will be a lot like flying westbound, but with less severe headwinds, while flying northbound will be like flying eastbound, but with less beneficial tailwinds.

Strategies

I fly some passengers who suffer from motion sickness, so I spend a lot of time planning around this stuff. In general, flying eastbound, I’ll go up above and accept a longer flight to get smooth air, since my passengers would rather be comfortable for 5-6 hours than violently ill for 3-5. Still, I can’t protect them from the turbulence when I have to land (fuel stop or destination).

Of course, I can’t stay above all day when the sun’s out — today, coming back from Charlottetown, I started at 2,500 ft in air so smooth you could do calligraphy in the back seat, but by late morning ended up at 10,500 ft over Quebec’s Eastern Townships trying to stay above the rising cumulus layer. Once my 30 minutes above 10,000 ft were up, I had to descend and subject my passengers to 40 minutes of turbulence below the clouds at the end of the flight.

If your schedule can handle it, there are some workarounds to minimize the damage:

• Start as early in the morning as possible, if there’s no fog or low stratus. Some pilots I’ve met like to be preflighting as the sun rises. If your family is willing to wake up at 5:00 or 5:30 am, go for it, and the flight will be more fun (plus you’ll have more of the day at your destination).
• If your route follows a shoreline or a wide river, fly over water instead of land (staying within gliding distance). Water tends to be cooler in the summer, and doesn’t throw up thermals as much. Often, the best break through a line of thunderstorms will be over water, but don’t let yourself get pushed offshore.
• Fly in the evening, especially if you have a well-lit destination for landing after dark. Summer evenings are long-ish, and the air tends to start calming down again around 7:00 pm, give or take, as the ground cools, the thermals die out, and the afternoon cumulus clouds flatten out and disperse.
• Split up the trip. Instead of two three-hour legs with a fuel stop on your westbound flight, fly halfway, land before lunch, and spend the day. The next morning (or that evening), fly the second leg in smooth air again. For example, I could have flown from Charlottetown to Quebec City, spent an afternoon and evening there, and then flown on to Ottawa the next morning.
• Stay on top as long as possible, and descend quickly at your destination. For passengers who suffer from motion sickness, popping ears are far preferable to a long time down low in turbulence.
• Take up soaring. Glider pilots love afternoon thermals, because the rising air lets them stay up almost indefinitely — that’s why you’ll often see gliders happy circling under a cumulus cloud, while pilots of powered planes are impatient to be back on the ground.

In the end, though, turbulence and headwinds are facts of summer flying, and not every day is a typical day — you could drag everyone out of bed at 4:30 or 5:00 am and still be in bumps the whole flight, and you could even end up with headwinds in both directions. Don’t pressure yourself to make the flight perfect and control things outside your control: just do your best with whatever you have to work with.

So where would you fly in this? There are thunderstorms right across the country and well north of the Arctic Circle, and then snow.

(Source: Environment Canada, Canadian Weather at a Glance.)

I had my first experience flying partial panel in IMC on Monday, coming home from Boston. It wasn’t the classic partial panel — a vacuum failure — but a failure of the attitude indicator instrument itself, followed by the airspeed indicator while I was on an ILS approach. The AI had been sluggish for a while, but I had told myself that it was still usable as long as I allowed for a few seconds’ lag. In IMC and moderate turbulence (with a bit of light icing to distract me), however, it was totally useless, and I ended up relying on the turn coordinator to keep the wings more-or-less level, with the heading indicator as a backup.

I’ve heard that partial panel in a slick plane with retractable gear can be a nightmare, but the Cherokee is so slow, draggy, and spiral-resistant that it wasn’t more than an irritant. I’m not sure that simulated partial panel under the hood does anything to prepare you for it, though, because the hardest part is recognizing that you have a problem in the first place (I’m also not convinced that flying under a hood does much to prepare you for flying in actual IMC, but that’s another posting.)

Losing the ASI wasn’t a big deal, since I was already on the glideslope and had a 10,000 ft runway ahead of me, so I just kept a generous power setting on the tachometer and burned off the extra speed in a long flare.

The plane is grounded until the pitot system is cleaned out and tested, the AI is fully overhauled, and new wiring is installed for the intermittent landing light.

The incident

I flew through some light snow showers on my way to Kingston with my daughter this morning, so I turned on the pitot heat just before joining the circuit to make sure the pitot blade was clear. At the end of the downwind leg I slowed the engine, reduced power, dropped flaps, verified 70-80 knot airspeed, turned a tight base over the icy water of Lake Ontario, then looked again at the airspeed indicator (ASI).

35 knots. Way below stall speed.

But the plane was flying fine. The nose wasn’t high, the controls weren’t mushy, the stall buzzer wasn’t blaring, the wings weren’t buffeting, and most importantly, the ice floes weren’t spinning and getting larger in the windshield. I gently pushed the nose down enough to speed up 5-10 knots, but still the needle didn’t move. I checked the altimeter and it was behaving properly, showing a slow descent towards field elevation. That meant a pitot failure.

The trickiest part was the turn to final, almost immediately after the failure, when I’d barely had time to process it — it’s easy to lose airspeed in a turn, even with a functioning ASI. After that, it was pretty much a normal approach and landing (no point declaring an emergency when the runway is less than a minute away). The ASI flickered back to life on short final to show that I was 5-10 knots above my normal approach speed. It froze again at some point during the flare and landing (I don’t look at the panel once I’m past the airport fence), then gradually climbed to 90 knots as I taxied in to park the plane.

On the way home from Teterboro Airport after a March break family trip to New York City, after 2.6 flying hours mostly in IMC with light to moderate turbulence. My older daughter in the copilot seat whipped out her camera and took this shot on short final on the ILS 32 at Ottawa/Macdonald-Cartier Airport.

We had been racing down the approach at 110 knots to get in ahead of an approaching level 2 cell (though we’d been through a few of those already), and tower turned the lights up to maximum to make sure we wouldn’t have to go missed. The airport was reporting RVR 4000 ft (in other words, you could see less than a mile forward on the runway), but the approach lights were bright enough that I made them out at 800 AGL and started to slow the plane. The runway itself popped into view at 600 AGL, and my daughter took this picture a bit after that.

As ominous as this looks, it would not count as anywhere near a low approach for an ILS. However, it’s worth mentioning that Ottawa was forecasting 3,000 ft ceilings and 5 miles visibility when we left Teterboro.

Remember which way the wind’s blowing.

Even if there are blue skies everywhere else, a cold wind will often pull streamers of lake effect weather off the Great Lakes, so if you’re downwind from (say) Lake Ontario or Georgian Bay, expect long streams of clouds with significant icing, snow, and low IFR conditions underneath, topping out somewhere around 6,000-8,000 feet (unless they hit hills like the Adirondacks, in which case the tops can shoot way, way up). This evening, the new photo of the day at Wikipedia (originally from NASA) is a beautiful colour satellite photo of streamers coming off the lakes (click on it for a much larger version), caused by what I’d guess is a low-pressure system centered in northern Quebec a bit east of James Bay. Notice the long fingers reaching out into central Ontario (off Lake Huron and Georgian Bay), Michigan, Ohio, and upstate New York.

My normal flying route from Ottawa to Boston or New York takes me across the St. Lawrence River, and depending on the wind, I can usually expect to have to overfly lake effect weather somewhere along my route. If the wind is from the west, I can expect to find it over Watertown, NY and the relatively flat area of NY state, possibly as far as Lake Champlain; if the wind is from the southwest, it will blow straight up the St. Lawrence towards Montreal, possibly boxing in Ottawa as well; if the wind is from the northwest, it will head towards the Adirondacks, and may throw up cloud too high for me to fly over; it will also blow off Georgian Bay across my route from Ottawa to Toronto, so even if the TAFs are CAVU for Ottawa and Toronto, it might be unflyable in between.

The trick in every case is to make sure that I can stay above the cloud, because it’s pretty nasty underneath it (not to mention inside). For emergencies, as you can see in the photo, there are usually clear spots between the streams for an emergency descent. If the streamers are over your point of departure or destination, on the other hand, forget about it. People on the U.S. side have it a lot harder in the winter, since the cold winter winds usually come from the northwest and blow over them on the southeast sides of the lakes. Aside from central Ontario near Georgian Bay, the Canadian side is usually clearer.

(Source: NASA Astronomy Picture of the Day.)

In plain language, that means that at 18,000 ft the wind will be from the northwest at 97 knots (180 km/h). My Warrior cannot fly that high (the theoretical ceiling is around 14,000 ft, with a lightly-loaded plane and lots of patience), but many light piston singles and twins can. Even at 12,000 ft, the winds are strong enough that I could point the plane into the wind, drop flaps, pitch for slow flight, and fly backwards over Ottawa; at 9,000 ft, I could still pretty-much hover or move backwards very slowly.

I flew from Ottawa to Sault Ste. Marie yesterday, then flew a Hope Air patient from the Soo to Kingston this morning, before making the short hop back to Ottawa in the afternoon.

Westbound

Flying westbound to the Soo is a slow prospect in the Warrior. The trip is a bit under 400 nm, but due to the headwinds, it generally takes around four hours. This time, it was all IFR, but at least it was smooth, the icing levels were well above me, and all the thunderstorm activity was about 50 miles to the north of my route. Everytime Toronto Centre gave me a new altimeter setting, it was significantly lower, sometimes requiring an altitude change of a couple of hundred feet, as I flew towards the big low parked over Lake Superior and the nasty weather around it. The IMC on my route from Ottawa, however, had a different cause: the tropical storms and hurricanes had pushed a huge amount of hot, humid air north above them, leaving a stationary front a bit south of James Bay (north of my route). Because the front was there for so long, what had been supposed to be nice and clear became cloudy and hazy, plunging us into unseasonable IMC of the summer variety.

Cold front

A cold front was be blowing through overnight, and I know that I’d have to fly through that cold front from the back side in the morning. For those who don’t fly, you need to understand that cold fonts suck — they mean lots of rain, thunderstorms, turbulence, fog, cloud, and just about anything else you don’t like (in the summer, they even bring tornados). Lying awake in my hotel room at 5:00 am I heard the rain pounding outside, and knew that the front was on its way through.

When I walked out of my hotel in the morning, I found an airplane sitting in the parking lot right outside the door. I wasn’t sure whether to take this as an omen of good luck (the flight will go fine) or a warning (it’s a good day to tow your plane on a trailer) — I guess superstition is too complicated. Here’s a second cellphone photo of the plane, this time from behind, the way I saw it when I walked outside.

Eastbound

IMC and thunderstorms are a bad combination, because when you’re in cloud, there’s no way to see a storm coming. Before I left, weather radar showed that all the activity was well north of my route, though the GFA called for isolated thunderstorms all over ahead of the cold front. I evaluated the situation, and decided to list every way I had to avoid storms:

1. try to stay out of cloud so I can see buildups coming
2. use my Stormscope to watch for lightning strikes
3. ask Flight Services for regular updates from ground-based radar

None of these is 100% reliable: between cloud layers (and the layers go very high ahead of a cold front), it’s often hard to make out buildups ahead, since everything fades to white; the Stormscope is a very blunt instrument and misses intense weather that doesn’t happen to produce lightning; and Flight Services is looking at outdated and and low-res lightning and radar pictures, when I can reach them by radio at all. As a result, I made a couple of rules for my flight:

• At least two of these three methods had to be available to me at every point during the flight, or else I’d abort and land at the nearest airport.
• All available methods had to show a wide, clear path with no storms moving towards it.

It turned out a bit bumpy, with a lot of rain, but nothing more disturbing. Three hours of hand-flown IMC has left me a bit tired now, though. As usual, the weather cleared up just before my destination, so I didn’t get to log an approach.

Northbound

With the tailwind from the southwest, I flew into Ottawa like a rocket: the whole flight from Kingston took about a half hour, and I made it home before the front hit Eastern Ontario. Unfortunately, I then had to wait 35 minutes for a cab to take me the last 10 km home. The wind’s starting to shake the leaves outside my window now, so I guess the weather’s on it’s way in our game of leapfrog.

Recency

Pilots have to do a certain amount of flying in real or similated instrument meteorological conditions (IMC) to keep their instrument ratings current (otherwise, they’re allowed to fly only in visual conditions). In Canada, the recency requirements include six hours and six approaches to minima.

Air mattresses and sailors

Note the phrase real or simulated IMC. Simulated IMC — flying wearing foggles or a hood to block the view out the window — is one of the sad jokes of aviation, since it simulates flying in real instrument conditions about as well as floating on an air mattress in a hotel pool simulates sailing in a storm on the high seas. While flying six approaches wearing foggles (with a safety pilot) meets the legal requirements for IFR recency, I don’t think it does much for actual flight safety, so I use it only as a last resort, mainly in the winter when IMC near the ground almost always comes with icing. As a result, on the rare days when I have no meetings booked with customers, no family committments, and beautiful low rain arrives without any thunderstorms or icing, I rush to the airport, get soaked preflighting the plane, ignore the people standing inside shaking their heads with pity and disbelief, and take off into the clouds.

Getting started

There hasn’t been a lot of rain this summer, but I did manage approaches in IMC in July on actual trips — one into Boston/Norwood, and one into Toronto/City Centre — so if I could manage a quick four approaches today, I’d be current until mid-January (when I’ll probably have to use the hated foggles). I called flight services, and they confirmed with ATC that a mid-day training flight would be OK. At the airport, I fueled the plane (full tanks are always a good idea in low IMC, since diversions can come unexpectedly), holding one hand over the tank opening to keep the rain out, then took off, and within a couple of minutes, there was nothing but white outside my window.

Smith’s Falls NDB 06 full procedure

I’ve developed a nice circuit of approaches around Ottawa. I started by flying to Smith’s Falls/Montague for the full procedure NDB 06 — that has me flying directly to an NDB (an AM radio navigation aid), flying away from the runway for two minutes, doing a funny kind of loop, coming back into to the navaid, then continuing at a pre-determined altitude until I either see the runway or run out of time. I was in and out of cloud bases at the minimum descent altitude of 980 ft MSL (564 ft AGL), but I did see the runway in time that I probably could have landed with a fast dive and some borderline aerobatics. Fortunately, that wasn’t my plan today, so I started climbing again for the missed approach and called back in to Ottawa Terminal.

Ottawa/Carp VOR/DME B with 21 DME arc transition

The second approach was the VOR/DME B (B is pronounced “bravo”) approach into Ottawa/Carp. For this one, instead of a full procedure (flying away from the airport, then reversing and coming in), I flew something called a DME arc, which is my very favourite IFR procedure. DME is an old-fashioned (pre-GPS) instrument that tells how far my plane is away from a UHF transmitter: in this case, from the Ottawa VOR (an FM radio navaid) on the Quebec side of the Ottawa River. To fly a DME arc, you simply turn 90 degrees from the DME at a pre-determined distance, and adjust your course so that the distance on the DME stays the same. If you flew long enough, you’d do a complete circle around the DME transmitter. There are all kinds of convoluted procedures for flying a DME arc, including messing with VOR radials, etc., but mine is easy: just turn the plane a few degrees away from the DME if the distance is getting too low, or a few degrees towards the DME if the distance is getting too high. It works a charm, and requires almost no work. I flew the 21 nm DME arc until I intersected a VOR radial that would take me over the Carp airport from the south, then followed the radial, lowering my altitude in steps: down to 1,400 ft once I was on the inbound radial, 900 ft (518 ft AGL) at 11 DME from the VOR (1.8 DME from the airport), and then climbing back up to 2,900 ft at 9.2 DME when I was over the airport. I saw the Carp airport at the last second, and again, could have made it in with some aerobatics, but this was a circling approach (I wasn’t lined up with a runway), and it might have been a bit too exciting. More on circling approaches later. Note also that at both airports, I was barely able to see the runway at around 500 ft AGL.

Ottawa/Gatineau VOR/DME 09

The third approach in my circuit is a straight-in VOR/DME 09 approach for Ottawa/Gatineau, on the Quebec side of the Ottawa River. The transition from the Carp approach is trivial: the Carp missed approach heads for the Ottawa VOR, and the Gatineau approach starts at the VOR, so just … fly to the VOR. For the Gatineau approach, I fly away from VOR on a predetermined radial, again, with a series of step-downs at various DME distances: 2,900 ft to the VOR, 2,400 ft until 5 DME, 1,300 ft until 11 DME, then 760 ft (551 ft AGL) until 14.3 DME, when I’m right over the airport and begin the missed approach. The weather was a little better here, and I broke out of the cloud bases around 1,200 ft MSL (1,000 ft AGL) and was able to see the runway clearly. That led me to think that I could expect about the same ceiling across the river at Ottawa/Macdonald-Cartier.

Ottawa ILS 07 circling 04 … no, straight-in 07 … no, circling to a taxiway … I mean 04

My last approach was back into Ottawa. All of the previous approaches were non-precision: the navigation aids guided me to the airport horizontally, but did not guide my altitude (except through step-down fixes). Ottawa has two more advanced navaids called ILS, that can provide a precision approach: not only does it help me stear left or right, but it tells me precisely what altitude I should be at during each stage of my descent. I have to fly around to the west side of the airport to get in line for the ILS 07, which I’ll be sharing with big transport jets. ATC tells me that there are three big jets on the way in, so I have a couple of choices: fly out 15 miles and have a nice, easy approach behind them, or turn in tight almost right over the final approach fix and rush down ahead of the jets. When I was an IFR student, I would always have taken the easy one because approaches seemed so hard to set up, but the tight one sounded like better practice (and is more realistic for a small plane at a busy airport), so I took that.

Terminal gave me an immediate turn and descent. I turned sharp (30 deg bank) and dropped the plane at 1,000 fpm to show them that I was capable of taking this approach without messing up their traffic flow. That was good enough, and they kept turning me in and dropping me until I joined the ILS right outside the final fix. I knew enough not to fly an approach at 90 knots in these circumstances, so I pushed the throttle forward and whizzed down the ILS at 120 kt. Satisfied that I wasn’t going to be in the way of the jets, Terminal turned me over to tower.

An ILS approach straight-in to a runway has very low minima: normally, you can fly right to 200 ft above the ground before you have to see the runway. However, I was planning on doing a circling approach to the runway near my parking spot (remember circling approaches from Carp?), so I needed legally to see my runway at 506 feet above the ground (880 ft MSL) and be able to stay at that altitude until I was lined up for my final approach. No dice. While the airport was reporting better conditions over the control tower, there was low cloud over the approach to 07, and I was coming down through 1,200, 1,100, 1,000 ft with no sign of either runway 07 or 04, though I could see a bit of ground straight down. At 950 ft I began a rapid call to the tower asking to cancel the circling and land on 07, but right at that moment — as I passed through 900 ft, 20 ft above circling minima — I broke out and saw the whole airport. In the middle of a sentence, I switched back with “correction: 04 in sight, continuing with circling approach”. Unfortunately, in those 2-3 seconds, I forgot that airports always look different in IMC, and I actually lined up with a taxiway instead of 04 and descended below the 880 ft circling minima. Fortunately, I caught the mistake before tower did, and — with some of the stupid borderline aerobatics I had been smug about avoiding at Smith’s Falls and Carp — sidestepped a half mile to the actual runway 04 and did a smooth landing on the wet pavement.

Lesson learned: circling approaches near minima really are a dumb idea, and it’s hard to make good decisions in a fraction of a second at the end of an approach. When the ceiling was close to circling minima, I should just have planned on the straight-in landing and an extra 10 minutes taxiing.

I’ve written about icing before, both here and here. Like storm clouds and scud running, icing is one of those things that pilots are supposed to avoid but occasionally stumble into anyway. The Canadian AIP contains some advice for pilots who end up in storm clouds (slow down, keep flying straight, and don’t worry about altitude, or something along those lines), and Rick Durden has written a good collection of scud running survival tips, but there is precious little out there to help us with dealing with icing on a day-to-day basis.

Fly high

OK, you’re planning to fly IFR on a day when there is no moderate or severe icing forecast, but there is cloud and possibly precip along the way, and the temperature at higher altitudes might be close to freezing. What do you do: fly low, to try to stay in the warm air, or fly high, where you might pick up ice?

My tip — and more experienced pilots reading this should feel free to correct me — is to fly high, even if you’re at or below the freezing level. Ice tends to accumulate at very specific altitudes: for example, you might pick up some light clear icing at 7,000 feet, but nothing at 9,000 or 5,000. In theory, then, you can either climb or descend to get out of icing. However, if ice should happen to accumulate quickly, and especially, if you should happen to be flying a heavily-loaded and/or weakly-powered plane, climbing might not be an option (for planes with boots, climbing too steeply is also dangerous, because the high angle of attack can allow ice to accumulate on the wing where the boots cannot reach it).

So, if your only choice is to descend, what happens? Assume that MOCA is 3,000 feet — if you’re already at 5,000 feet, the temperature drops a bit, and you pick up ice, you have only 2,000 feet left to descend safely in the hope that the ice will melt off; if you’re at 9,000 feet, you have 6,000 feet to descend to melt off the ice. That leaves you with a lot more choices. It may even be that 5,000 feet is the icing altitude for much of your route, but you’ll overfly it without ever knowing.

Of course, you don’t want to try this without some hope of warmer air underneath — if there’s an inversion causing freezing rain on the ground, descending probably is only going to make things worse. On a typical spring day or summer day, though, with some cumulus cloud and near-freezing temperatures at cruising altitude and a reasonably low MOCA below, I think that flying high makes more sense than flying low — like always, if you run into any trouble, your altitude is like money in the bank.

I’m going to be contrarian and suggest the opposite — get out there and experience as much as you can. Deliberately shoot approaches that are below minima. Fly in cumulous cloud and even in some (lowish) towering cumulus. To understand why, consider two scenarios.

Scenario 1

A year from now, you’re at the end of a three-hour flight, all in cumulus, with light-to-moderate turbulence the whole way. You’re frazzled and queasy yourself: one of your passengers has already thrown up twice and is begging you to land, and the whole plane stinks. The rental-car place at the airport closes in an hour. With the headwind, you’re not sure you actually have the full IFR reserve you planned on. You start the non-precision approach, expecting a much higher ceiling and an easy landing, but at MDA you’re just getting glimpses of the ground. You’re drifting around on the approach because you’re worrying about getting your pax on the ground. It looks like you’re right at the cloud base — just another 50 feet lower would have you clear, and you could switch to VFR (well, SVFR) almost immediately and finish the landing. Or, alternatively, you hit the MAP, and just as you’re starting to go missed, you can suddenly see the airport — almost right below you — through a break in the clouds.

Scenario 2

You’re at exactly the same airport, with exactly the same weather conditions. However, you’re alone in the plane (or with a flying buddy). You started out at an airport an hour away, where conditions are MVFR or VFR, assuring you of an easy return when you’re done practising here. You shoot the same non-precision approach, but this time, you have no intention of landing. You notice how you can see straight down at MDA, but you have no forward visibility. You drift slightly, but correct immediately because you’re not worried about whether you’ll be able to land. As you hit the MAP and start the missed approach (which was your plan all along), you notice the airport right below, and remind yourself to remember how it would not be possible to land safely at this point even though you saw the airport.

Are they both dangerous?

There’s no question that Scenario 1 reads like the beginning of an NTSB crash report (in fact, it has enough risk factors to make up several NTSB reports). But what’s the real risk here? Is it that the pilot is not skilled enough to handle the plane in IMC? The pilot and passengers in the first scenario are at an enormous risk of dying, not because of the pilot’s ability or inability to manipulate the controls and scan the instruments, but because of the pilot’s ability or inability to make difficult decisions. That’s the biggest problem with IFR training in both Canada and the US — 90% of IFR training focusses on how to handle the plane and follow finicky hold and approach procedures within tolerances, but 90% of real IFR flying is making complicated decisions like the one in scenario 1. You do not learn much useful about IFR flying by going round and round your local training area planning hold or approach entries, either under the hood or in actual IMC. Nobody does anything stupid IFR until they actually have to get somewhere.

I’d suggest that, even though the approach is below minima, Scenario 2 is not unacceptably dangerous (since there’s no temptation to try to land); in fact, scenario 2 is the kind of thing that IFR pilots should get out and do as often as possible. The more a pilot practises shooting low approaches that he or she has no intention of landing, the less likely a pilot is going to be fooled by the temptation to duck and dive under minima because of a glimpse of the ground or the airport — the pilot learns what conditions for a missed approach really look like (i.e. not necessarily white outside the windshield), and will be more confident about the choice to go missed in Scenario 1. I did a whole bunch of non-precision approaches like these one day last fall, and it was a great experience; I’m hoping to do the same thing again in a week or so, now that the freezing level is lifting.

Despite all the practice I’ve had, I’m not much better at the mechanical parts of IFR flying than I was in summer 2003 when I got my instrument rating (I’ll be repeating the IFR flight test this summer — in Canada, we have to retake it every two years). I hold altitude and heading a bit better that I did then, but it’s nothing like the improvement in airmanship that you get from two years of VFR flying. The big difference between then and now is what I’ve learned about (a) weather and (b) the ATC system. I did well on my written IFR test, but I cannot believe how little practical knowledge I had of weather then, not to mention of how ATC really worked. It takes only a few bad encounters with weather phenomena to teach you to pay a lot more attention to meteorology, and to realize that reading the TAFs, FDs, and (G)FAs is only a tiny first step to planning a flight: if you cannot explain why a TAF or (G)FA is forecasting the weather it is, you’re not ready to take off yet. And it takes only one long vector on a dark, rainy night to teach you how to learn about traffic flow near big airports and how to plan around it.

When weather permits, VFR is often a good choice: it gives you more control over your route and altitude than you would have IFR, generally speeds up the trip (since you don’t have to be spaced and sequenced as much during departure and arrival, especially at busy airports), makes it easier to avoid icing in winter time, and just all-round feels nice. When there are clouds somewhere along the route, however, you have to make an important decision: VFR underneath, or VFR over the top?

The decision is hardest when the clouds are right around the best cruise altitudes for your plane, say, 3,000 to 8,000 feet for a normally-aspirated piston aircraft like my Warrior. If you fly underneath, you could end up dealing with precipitation, marginal visibility, hills and towers, and (of course) lots of turbulence; if you fly over the top, you could end up dealing with strong headwinds, and, most importantly, you could get stuck up above an overcast. For my return to Ottawa from Teterboro, mindful of the Catskill and Adirondack mountains along my route, I chose to go on top at 9,500 feet for the smooth air and lack of mountains to fly into; and yes, I got stuck.

I knew that things weren’t going my way when the broken cloud layer closed up to an overcast near Saranac Lake, NY instead of breaking up to scattered. I checked the Massena, NY ASOS (I had planned to descend there, over the flat land) and it was also calling overcast; the Ottawa ATIS, which was coming in from 100 miles away at that altitude, was calling broken clouds. Halfway between Saranac Lake and Massena, I was handed off to Montreal Centre for flight following, and I talked to them about the situation, warning that I might need an IFR clearance to get down. The controller insisted that the latest weather for Massena was showing scattered (as I’m sure it was, as far as the data available to the controller went), so I said that I could wait until closer to Ottawa.

In the end, I got my clearance for an IFR descent inside Ottawa Terminal airspace. I knew that the cloud layer was too thin to hold any large, supercooled water droplets, so icing wouldn’t be a major issue; still, I activated all of the meagre ice-prevention gear at the Warrior’s disposal before starting down: pitot-static heat on, carb heat full, heat on defrost. The clouds were less than 1,000 feet of stratocumulus, and I was through them and back VFR in a couple of minutes, as expected.

Now, let’s try some what ifs. What if I hadn’t been flying an IFR-capable aircraft, or weren’t IFR current? There was no hole that a VFR pilot could have used — the biggest one I saw near Ottawa was about 50 meters long, and mostly there were no holes at all. Canadian VFR pilots require a special rating and 15 hours instrument time to fly VFR over the top, but US pilots have no such requirement. If I had been a new American PPL, with (say) 70 hours experience, arriving at Ottawa stuck on top of the overcast with only my required 30 minutes VFR fuel reserve, how would ATC have dealt with me? Obviously, Montreal didn’t have up-to-date information about Massena — might they have sent me somewhere similar, where I might have found nothing but more overcast? The centre controller could tell that I wasn’t in trouble by my calm tone of voice and the specificity of my request (“I might need an IFR clearance to get down” rather than “I need to find some way to get down” or even “oh my god! oh my god!”), so I was handled much more casually than my hypothetical VFR-only pilot. I’d like to know how they would have handled that pilot, who might have been getting more and more panicky as the fuel got lower and the cloud layer stayed solid underneath.

My flight met all the requirements for VFR over top — the sky was clear at my point of departure, Massena was forecast scattered, giving me a way down, etc. — but I still got stuck. Does VFR over the top make sense for non-instrument rated pilots? Certainly, it’s safer than scud running around mountains, but I would not have wanted to be up there without the IFR option. At least a much bigger required fuel reserve would be a good idea.

I was a few kilometers from home just before 7:00 am, running in -10 degC weather, when suddenly I felt an intense pain with every deep breath I took. When I stopped, I realized that my upper back was somehow injured, and that I could barely walk, much less run. I shuffled slowly, like an old man, for about three quarters of a kilometer past many houses where I could have knocked on the door and asked for help, but was too shy to risk waking people up. Finally I came to a public school, and fortunately the front door was unlocked — I found an early-rising teacher with a cell phone, called home, and was picked up in about 10 minutes.

I’ve always known that eventually, something would happen during a run that would prevent me from finishing, though I’ve always assumed that it would be a leg injury. That could be a very big deal for a winter runner — I have run in temperatures as low as -25 degC this winter, and when you’re running, you have to dress relatively lightly to avoid overheating. An injury on a deserted country road, outside of cell phone coverage, could possibly be fatal. Personally, I run in the middle of Canada’s fourth-largest city, so I know that there are always people around to find me, even if I suddenly crumple unconscious with no warning (backup #1); I’m the first one awake in my house, but I always leave a note saying where I’m running and when I should be expected home (backup #2); and finally, I know that there are people I can call, starting with my spouse, to come and pick me up if I’m too injured to keep going (backup #3). If I lived in the country, running would be a whole different kind of thing — I could run on the road, and risk being killed by the reckless, high-speed drivers who seem to fill country roads all over North America, or I could go on isolated paths and just hope that I was still conscious and within cell phone coverage if anything happened. Or, more likely, I’d run only with a buddy — that’s a kind of backup that can work.

As pilots, we get pelted with safety warnings about almost everything, to the point that we eventually become a bit numb and cynical. Really, though, I think that just about all of those warnings come down to the same thing that saved me in my running: backup. Staying current on partial panel? Backup, in case your vacuum pump fails. Setting personal IFR minima of, say, a 1,000 ft ceiling? Backup, in case you have to go VFR underneath. And so on.

I’ve had exactly one icing encounter so far in my flying. I was coming home from Toronto in IMC last last winter (or early spring — I don’t recall) when I noticed that the temperature was lower than forecast at my altitude, and that I was surrounded by drizzle. I kept an eye on my outside air temperature probe — the Piper Cherokee‘s icing early warning system, since it is a thin stick poking out the front of the windshield — and soon noticed that a small piece of clear ice was forming on it. I asked for a lower altitude, descended 1,000 ft, and the ice disappeared. I continue to Ottawa and made a slightly-fast, no-flaps landing, just to be safe.

I was never in any serious danger during that trip, because I had all kinds of backup, even before I saw any ice:

1. I had already listened to the ATIS for the nearest big airport, Trenton (CYTR), and knew that the surface temperature was 6 degC, so there was warmer air below me (an underpowered plane like mine cannot necessarily climb above icing, but anybody can descend).
2. I tune in NDBs enroute to keep myself entertained, and in this case, I already had the Trenton NDB tuned and identified, which would be the first step for an approach. I also had the Trenton approach plates open, since I’d used them to get the ATIS frequency.
3. Even though I was only 1,000 ft above MEA when I saw the ice, I was much further above MOCA, flying over flat terrain with few towers.
4. I knew from the ATIS that the ceiling below me was at least marginal VMC.

My first backup plan was to change altitude, and that worked. If it hadn’t, I would have shot an approach at Trenton just until I broke out, and then (depending on the actual ceiling and whether I was still picking up ice) either declared an emergency and landed at the military base there, or (most likely) broken off the approach and proceded VFR at 1,000 ft AGL (well under the ceiling) along Lake Ontario just off the shore until Kingston, where the airport is right beside the lake. Other options included staying on my course IFR but descending to MOCA, in the hope that would melt off the ice, but it seemed like a less promising approach, since once I was at MOCA, I wouldn’t have any further backup if things didn’t work.

I’ve already written about my experience with Hope Air. That’s another place that backup is a nice thing. Usually, there’s a backup pilot for every flight, and in my case, it’s often Frank Eigler with his twin-engine, ice-certified Aztec. Knowing that there’s a backup takes a lot of the stress out of both flight planning and winter running. Now, it’s time to get myself to the physiotherapy clinic for some more repair work on my upper back, which, fortunately, is much less expensive than body work on my plane.

Ice in Ottawa

Philip did a good job using layperson’s language in his piece, so I’ll try to do the same here. In general (ignoring local effects like weather around the Great Lakes), there are four bands of weather that can hit Ottawa over the year, stacked from north to south like the layers of a cake. First, there’s the really cold, dry Arctic air furthest north. In the summer, that’s far out of reach; in the winter, it often pushes down into Ottawa giving us cold temperatures (too cold for icing) and good visibility. To the south of that, there’s usually a band of mucky, wet air that hovers just around freezing and causes most of the icing problems for airplanes. In the summer, that air is up around Hudson Bay; it passes through Ottawa in the late fall on its way down to the northeastern US, stays down there for much of the winter (occasionally poking up into Ottawa to annoy us), then passes back up through Ottawa in the early spring on its way back to the Arctic. South of that is the dry, moderate air that gives a nice spring, summer, or fall day. We get that for a lot of the summer in Ottawa, and (I’m guessing) it spends the winter down in Florida, giving nice weather for the snowbirds. Finally, the layer furthest south is the hot, wet air from the Caribbean and Gulf of Mexico. In summer, that air sometimes pokes up into Eastern Ontario bringing thunderstorms and other violent weather, but it seems to spend most of its summer southwest of us, tearing up the U.S. midwest.

So, the point of all this is that (if this winter goes like most) the wet, icy weather will move south soon. Philip may have to deal with it all winter, but we (I hope) will soon have more nice, safe, cold days for flying. Of course, with global warming, we could end up getting more of New England’s winter weather, and then winter flying in Ottawa will be much less pleasant. Keep it nice and cold, please.

Freezing levels

Once the freezing levels come down low enough, clouds can mean ice, and most single-engine planes (and many twins) are not equipped to deal with that. It doesn’t have to be winter weather for icing to be a problem: with the standard temperature lapse rate (i.e. no inversion), a nice warm fall/spring temperature of 8 degC on the ground means that I’ll be hitting icing conditions at about 4,000 feet, which gives me very little room for IFR flight (the lowest IFR obstacle-clearance altitudes are typically around 3,000 feet, and I like a 2,000 foot safety margin from the icing). If the clouds are high enough, I can go VFR underneath them; if the ceiling is low, I might just have to wait.

Actually, the story is more complicated than that. I will admit that last winter — my first with an instrument rating — I flew a lot in cloud at below-freezing temperatures. The only ice I ever saw was a tiny piece of clear ice starting to form on my outside air temperature probe, in drizzle around -1 degC. I immediately descended 1,000 feet, the ice melted off, and I finished my flight uneventfully aside from a slightly fast, no-flaps landing. What if it hadn’t melted? Well, I could have descended further below MEA to MOCA (the minimum safe IFR altitude); if that didn’t work, I had already listened to the weather from the nearest big airport, which was reporting surface temperatures of around 6-8 degC (memory is getting fuzzy), and I had the navaids for a nearby approach tuned in, so I could have shot the approach until I broke out from the clouds and then decided whether to land or continue VFR underneath. In other words, I had more than one very good out. Would I have tried the same thing with freezing temperatures down to near the ground or over hilly or mountainous terrain? Not a chance. There’s always got to be a way out, preferably several.

Too cold for icing

More typically, though, I can fly in IMC in the winter without worrying, because as the winter goes on it gets too cold for airframe icing. According to this bulletin to FAA controllers, at -16 degC, 95% of droplets in a cloud will have frozen into ice crystals (which won’t stick to the airframe); at -25 degC, 99.9% of the droplets will have crystalized. I live in Ottawa, where people refer to -16 degC on the ground in February as a mild day; I’ve even flown on -16 degC days without preheating (I promise never to do it again). And, when there’s no inversion, -16 degC on the ground might mean -30 degC at altitude, where there are definitely nothing but ice crystals in the clouds. So come January and February, whenever Ottawa is under a cold arctic airmass, I can happily go and fly in the clouds without worrying about icing at all. However, when that warm wet gulf air mass pushes up from the U.S. and the surface temperature rises to, say, -5 degC or even 0 degC, I’m back to VFR only. Once the surface temperature gets above 5 or 6 degC, I can fly again, because I know that I’ve got warmer air underneath to get rid of any ice I might pick up. That means that the worst time for icing is not winter but late October, November, March, and early April, where the surface temperature is just a bit above freezing.

I think it’s a big shame that training courses for instrument ratings do not spend much more time on icing. Simply saying to an IFR pilot “Don’t fly in clouds below freezing” is roughly equivalent to saying to a VFR pilot “Don’t fly when there are clouds in the sky” or saying to a teenager “Don’t have sex” — they’re probably going to do it anyway, so you might as well teach them how to do it safely. Sometimes flying in icing conditions is OK and sometimes it’s not, and we really need more resources to help new instrument-rated pilots make more informed decisions and develop strategies for flying safely during the icing months.

Winterizing the House

Winterizing a house in central Canada means disconnecting the hose and turning off the outside water tap (otherwise the pipe can freeze and rupture), putting up storm windows, adding new weather stripping under the doors, changing the furnace air filter, getting out the shovels and sand and salt, putting away the lawn and porch furniture, and making sure all the fire and CO detectors work. It’s really the first of the pre-Christmas rituals: when I’m putting up the storms, I find myself starting to think about what presents I’m going to buy people, and I start deciding that maybe it won’t be so bad hearing tinny, piped-in mall Christmas muzak after all.

Winterizing Myself

Winterizing a person is a bit of a different kind of challenge. Of course, you start by putting away all the summer clothes, the thin pants and shirts, the shorts, and so on, and pulling out the sweaters and thick chinos. The thick winter coats, boots, hats and mittens come out of the basement and up into the coat closet, replacing the rain coats, rain boots, and umbrellas of the summer. For the last couple of years, however, winterization has also meant spending 10-15 minutes every morning in front of a home light therapy lamp, to help my body and brain get going with the shorter, dimmer daylight that we have to live with until spring: I decided that I don’t want to drag myself through any more winters with a fuzzy brain and heavy limbs.

This year, however, I’m adding something new: I managed to start running again last spring, and this time, I don’t want to have to give it up for the winter. I’m still running in the early morning, before sunrise, but plan on switching to early afternoon in November to take advantage of the extra warmth. To help me through the cold temperatures, I paid a visit to the Running Room and spent way too much money on layers of winter running clothing. So far, I have not had to deal with temperatures below 0 degC, but I really want to make it all the way through to spring this time. I find myself running shorter distances, slower, than I was in the summer, but as long as I keep moving, I’ll be happy.

Winterizing the Plane

Tomorrow I’ll bring the plane into the shop for some winter preparations. With multigrade oils, it’s no longer necessary to change to a different oil type for winter flying, and my muffler shroud has already been inspected for potential carbon monoxide leaks into the cabin heater (an annual inspection is mandatory in Canada), but I have two big problems that will make winter flying more than a bit unpleasant: my heater is jammed off, and my pilot-side floor vent is jammed open. I have flown with outside air temperatures as low as -37 degC; at full blast my heater can just barely keep the plane warm under those conditions; I don’t want to imagine it with the heater off and cold air blowing on my feet.

Most pilots also remove their wheel fairings for the winter. The official reason for doing so is to avoid having hidden ice build up inside, adding weight and throwing off the plane’s balance, but I think the main justification is that it’s just too hard to keep the tires inflated with the fairings in the way when it’s so cold out: who wants to take off mittens and fiddle with the valve underneath the fairing? I’ll probably take my fairings off again this winter and learn to live without the extra 7 knots that they provide.

Winter flying can be fun. The air is often brilliantly clear (compared to the soupy muck we get in the other three seasons), takeoff and climb performance is awe-inspiring, and airports are not crowded: sometimes you can fly into a largish airport like North Bay and find out that you’re their first 100LL fuel sale in three or four days. One big advantage of the cold up here is that it’s often too cold for aircraft icing, so it becomes reasonably safe to fly in cloud again: the most dangerous times for aircraft icing are October and April, not January or February. And sitting snug in a warm cockpit looking out at the brilliant frozen winter landscape underneath is awe-inspiring.

On the other hand, like winter running, winter flying means spending more time to do less. Taking covers off the wings, stabilator, cowling, and canopy before every flight and then putting them back on afterwards adds at least 15 minutes to every trip (more in a strong wind). Once the temperature is below about -5 degC, I have to remember to call the night before to have my engine heater plugged in, or else wait for 20 minutes while the Hermann Nelson kerosene heater blows hot air under my cowling. Sometimes, especially when I’m planning a family trip, I’ll have the plane towed into the club’s heater hangar overnight so that we can preflight and load up inside, but that often means an extra half hour before planes can be rearranged and the door opened. There are also other unexpected surprises, like finding out that the snow hasn’t been plowed off the apron.

Winter flying also means winterizing the pilot. I always dress so that I’ll be comfortable making a two-hour walk through the woods, and still alive after a night out there: in addition to a thermal base layer, extra socks, waterproof overpants, thick boots, hat, mitts, scarf, etc. I carry a solar blanket, and can also use my cowling cover as an insulated blanket. There’s a small hatchet (CAD 5.00 at Canadian Tire) for cutting firewood or smashing a window to get out of the plane, and a waterproof package full of matches, since my flint-striking and stick-spinning skills are…well, non existant. A big advantage of dressing that way is that I’m comfortably warm outside while preflighting the plane, except when I have to remove a mitten to check the fuel or oil. When I’m warm, I’m not tempted to rush the preflight even with a temperature of -25 or -30 degC and a wind whipping across the airport. Unfortunately, all those layers leave me feeling like a Malaria sufferer about 5 minutes after I enter a heated building, so I have the extra hassle of changing back and forth to remove the thermal underlayers.

Still, with all of that, I will be flying again for this, my third winter in the air, hopefully with the floor vent closed and the heater running nice and hot.