Flying inadvertently into cloud (instrument meteorological conditions or IMC) is easier than you may think. Sudden precipitation may result in a loss of visual to the ground. Low light conditions or increasing darkness may cause you to lose sight of the ground
The Piper PA-44-180 Seminole was on a local VFR flight from London International Airport (CYXU) when the pilot declared an emergency. The aircraft was six miles westsouthwest of CYXU and the pilot had lost ground contact. The pilot later regained ground contact and landed safely.
A special weather observation made at the time of the incident reported wind 210 degrees at 13 knots, visibility 10 miles in light snow, ceiling overcast at 6,900 feet. It is likely that it was snowing more heavily six miles away where the aircraft was flying. Ceilings can fall more than 2,000 feet and visibility can drop more than two miles when it starts to snow. This may result in a sudden loss of visual contact with the ground.
A C-172 pilot called Vancouver Terminal and reported that he was in cloud. He was radar identified 10 nm NW of Abbotsford at 2,800 feet and given a climb and a westerly heading to fly. The pilot then reported he had just hit a tree. Westerly vectors and a climb were continued and the pilot eventually became visual and was able to land at Boundary Bay, B.C. The minimum safe altitude in the area the pilot flew into cloud is 7,000 feet.
This aircraft was on a training flight in a practice area with an instructor and student on board. The instructor was obviously trying too hard to complete a training flight in poor weather conditions when they accidentally flew into cloud.
CARs state that under VFR conditions we are to maintain clearance from cloud of one mile horizontally and 500 feet vertically. This instructor had been skirting very close to the cloud horizontally and vertically to complete the flight.
A C-182 Pilot departed Castlegar for a 90 nm flight to Vernon, B.C. 45 minutes before grounding. A pilot report from another aircraft indicated a solid wall of cloud about 40 nm west of Castlegar. This information was passed to the C- 182 pilot. Just short of half way to Vernon, the C-182 pilot contacted the Vancouver Area Control Centre and reported that he was in cloud and climbing. YVR ACC radar identified the aircraft just in time to watch it disappear off radar. Due to the bad weather and heavy snowfall, the aircraft was not located for 3 months.
The C-182 pilot knowingly flew into poor and deteriorating weather conditions as daylight was fading. He continued to push on as the weather got progressively worse. Vernon was home and he likely was suffering from a severe case of “Gethomeitis.” In his case, and for his passenger, it was fatal.
All of the pilots described in the incidents above, were subject to a mindset of getting to a destination, or getting the job done. This mindset can cause us to ignore weather reports, weather forecasts, and pilot reports as we blindly continue on. All of them had the opportunity of deciding against the flight, or turning back at some point during the flight.
As mentioned above, a sudden snow shower or a sudden heavier snow fall can drastically reduce ceilings and visibilities. Sudden rain showers can do the same. Combine a snow shower or rain shower with low light conditions or approaching dusk and we can see that a loss of ground reference can easily happen.
Too often we just check the METARs and TAFs and don’t bother with the GFAs or get a briefing from an FIC specialist. The weather outside the airport control zone may be significantly different than the reported or forecast weather at the airports. The weather in valleys or near any upslope condition may change the local weather.
The METARS and TAFS may not indicate showery conditions within five miles of the airport, but a GFA may indicate the possibility of snow or rain showers. Any time they do, we must be prepared for a sudden change in ceilings and visibilities.
The CARs state that we may fly in Class G airspace with visibilities as low as one mile and ceilings as low as 1,000 feet. If we do, and sudden snow or rain starts to fall, we may be in trouble instantly. I personally use minimums of 3,000 feet and three miles for any VFR flight where the possibility of showers are forecast. There is a difference between what is legal and what is safe, especially in mountainous regions.
Weather forecasts are not always accurate and there are times when we feel that we can make a flight despite the forecast. Some of our flights are successful under these conditions. This tends to confirm that we know better than the forecasters.
We should begin every flight with the mindset that we will return to our point of departure, or we will land at an airport en route if the weather deteriorates to a pre-decided limit.
The more we know about the enroute weather, the more prepared we are and the less set our minds are about completing the trip.
As we see from the incidents and accident described above, a press-on mindset may not get us to our destination anyway. Even if it does, the stress or sheer terror experienced may make us wish we hadn’t tried.
Dale Nielsen is an ex-Armed Forces pilot and aerial photography pilot. He lives in Abbotsford, B.C., and currently flies medevacs from Victoria in a Lear 25. Nielsen is also the author of seven flight training manuals published by Canuck West Holdings.