Great flying weather, and a bit of boneheaded flying

Warm front pushing in, ceilings at 800 ft AGL with occasional 400 ft, light rain, freezing levels above 10,000: it looked like great flying weather to get in some IFR approaches in actual IMC.


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.


About David Megginson

Scholar, tech guy, Canuck, open-source/data/information zealot, urban pedestrian, language geek, tea drinker, pater familias, red tory, amateur musician, private pilot.
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