Whiteout and Flat Light Considerations
As we know from our previous blog (see Arctic Flying: Part 1), there are many optical hazards while flying in the Arctic region. The snow covered ground combined with overcast or extremely sunny conditions can cause either flat light or whiteout conditions. These conditions have proven in the past and are continually proven today to be an extreme hazard while flying. In fact, the Transportation Safety Board (TSB) reported that from 2008 to 2017 there were 18 accidents in which whiteout was a major contributing factor, with 6 of these accidents having fatal results. Since 2005, the NTSB has suggested that operators that frequently fly in areas prone to flat light or whiteout conditions should possess a current helicopter instrument rating and should be equipped with radar/radio altimeters to avoid these incidents and accidents, but it still isn’t enough. Now, let’s explore some additional precautions to take to ensure the highest level of safety while flying in these conditions.
Whiteout is when an aircraft is surrounded by a uniformly white glow from the sun’s reflection off the snow. Flat light is the condition in which diffused lighting occurs due to cloudy skies, especially when there is snow covered ground below, reducing or eliminating contrast and shadows. Both flat light and whiteout distort perceptions of depth, distance, altitude, closure rate, and topographical features.
- NEVER takeoff in whiteout conditions.
- When planning your flight, take into account the 5 Ps: proper planning prevents poor performance.
- Obtain and maintain an instrument rating.
- Continually give and request PIREPS while flying in and around areas of whiteout or flat light conditions, especially when these areas are in remote locations.
- For helicopters, as you approach a touchdown zone, keep in mind that you may be engulfed in a cloud of white. This may cause spatial disorientation, so always leave an out when in approach and landing during these conditions.
- For all phases of flight, particularly takeoff and landing, always have a visual reference point in order to assist in keeping altitude, distance, and other factors in line. Keep the reference point on your side and never fly past your last point of reference. If you lose your reference points, turn back toward the previous reference point or consider climbing and completing the flight under IFR.
By being prepared for and having decisions made ahead of time, flying in areas of visual illusions and changing weather patterns can be as safe as any flight. Remember to always follow operational and self-imposed limitations, guidelines, and requirements, along with using your best judgement to avoid accidents and incidents. If you prepare and plan your flights, accidents while flying in flat light or whiteout conditions can be avoided.