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4 Aug 2017

Drone Weather: Smoke in the forecast

Anyone that is in British Columbia right now is very aware of the forest fires in the province not just because of the news but because of the severe air quality issues. I wanted to take this opportunity to do a bit of a meteorology and forest fire review with our alumni. We are going to look at forecasting, analysis of NavCan’s weather products, and forest fire rules.

Weather

Below is a great satellite view of what is going on in BC right now. Have a look at this image and notice that the smoke from the fires is flowing south from the middle of the province and west from the Rockies.

Image may contain: water, outdoor and nature

What is a bit out of the ordinary with the above image is this east to west air movement. Weather normally moves from the west to the east.

Now have a look at the below image from the NavCanada GFAHere you are going to see the reason for this movement as well as a wealth of other information that helps us understand what is going on.

What you will see in the above image that can be seen on the satellite image:

  1. The big L is a low pressure centre that is pulling the cooler and higher pressure air down from higher in the province. This is why we have weather moving from the east and the north towards that
  2. The yellow dashed line outlines the smoke and the text inside that yellow blob is information relative to that smoke.
    1. PTCHY = Patchy visibility in that area
    2. 3-6SM = Visibility of 3-6 Statute miles
    3. FU = Smoke (fumée)
    4. LCL = Local patches with lower visibility
    5. 1SM = 1 statute mile of visibility in the local areas

Below is an even better look at the effect of this low pressure

There are a lot of other things going on there, so if you don’t recognize anything on the GFA above, make sure to check out your Aerobotika UAV Ground School text book or the information on the NavCan website linked above.

What does this all mean?

We care about this because there are a lot of rules and safety considerations in these conditions. Without a solid understanding of aviation weather, the physics of flight, and the UAV flying rules in Canada you could be risking a crash and creating a major safety hazard.

Flying in and around forest fires

For starters, it is plain ignorant and irresponsible to fly your UAV in a forest fire area. The risk to forest fighting air traffic is immense. You are flying in a much busier airspace than normal and the chances of contact with another aircraft is much higher than normal.

Next, you are in Class F CYR airspace and you cannot fly there without explicit permission from the fire fighting agency.  Areas effected by forest fires become class F from the ground and a 5 NM radius from the fire.

Forest fire area are posted by NOTAMS. If you are following proper procedures, you are going to see this and will be avoiding the area.

This is an example of a NOTAM that is posted for the current fire condition.

Now consider the vertical convective air movements caused by heat. Fire itself is going to create a massive change in temperature that would have very strong upward currents also creating localize low pressure that will thin the air and cause issues with your aircraft’s ability to create lift.

Flying in the smoke

All of us operating commercially in Canada have specific rules and conditions that state a minimum visibility. This visibility is critical to VLOS and maintaining visual contact and control. The most significant issue with the smokey conditions is the reduction of visibility.

Also take into account the sensitivity of our instrumentation when it comes to the particulate matter in smoke. Some sensors and measurement devices can be very sensitive and could be effected and caused to give false or inaccurate readings.

Health Considerations

The next thing we have to consider isn’t even related to UAV at all. Perhaps something that we should be adding to the Human Factors section of the course is pollution and the possible effects of smoke on your health. In parts of BC you will currently have difficulty breathing, your eyes will sting, and your respiratory system is going to have to work harder to get oxygen and filter out the fine particulate matter associated with smoke.

Metro Vancouver’s air monitoring for our local station

There are some excellent resources available both at Metro Vancouver and Environment Canada to understand the effects of this air quality on yourself and your crew.

Unmanned Aircraft can be good for fighting fires

This is so true. There are so many reasons that we should be using UAVs in forest fire fighting, and it is legal. Anyone that has received permission from the fire fighting agency responsible for the area can be involved with unmanned aircraft. The keys to doing it right are to understand the risks and physics behind it, to get permission, and to understand how to operate within all of the rules and specific conditions of your SFOC.