Jim Hilton pens a column on forestry each week for the Tribune.

Jim Hilton pens a column on forestry each week for the Tribune.

FOREST INK: Helicopters are still important for forestry work

Suddenly looking down thousands of feet to the river valley below is a moment to remember

Last weekend I got a chance to see how a small drone works on a windy day over a lake. This relatively tiny drone is small enough that the operator does not need a licence but it is packed with a number of options that makes it easy to operate. The drone as well as the camera have stabilizers which help to take some very impressive videos or stills. The automatic return feature will bring the drone back safely if you take some safeguards. It is a good idea to keep it in sight as well as monitoring the picture which gives you instant feedback of what the drone is doing.

While the drones are impressive there is nothing like the thrill of riding in a helicopter especially when it is in the mountains. I recall the first time I flew in a helicopter was on a range inspection on the Gang Ranch near Lorna Lake. Flying across an alpine meadow and suddenly looking down thousands of feet to the river valley below is a moment to remember.

Once I started to work in the forest inventory section we were using helicopters on a daily basis. Rotary wing machines (another name for helicopters) were ideal for transporting field crews to isolated locations as well as allowing the forest classifiers to place air calls at key locations for verification of the forest cover labels.

Later on we used helicopters to establish photo plots. Two Hasselblad cameras were suspended below a helicopter in a specially made aluminum tube. The forest classifiers would pre-select the photo location on an air photo which would be given to the flying team who would first fly over the selected location and describe the stand and then return and take a series of photos (I think it was six pairs) over the pre-selected spot.

In the 1980s and 90s film cameras were used which necessitated the removal of the film from the camera inside a black bag so it was not exposed to the light.

The processed film was then used by an operator using an instrument that was able to measure the height of the trees along with other critical information about the stand of trees. While helicopters are amazing machines they do not stay in the air very long when the motor quits. If the chopper is high enough the pilot can usually land safely through a procedure called auto rotation which all pilots have to practice.

Most of our photos were taken relatively close to the forest canopy so on a flight near Tatla Lake our pilot lost control when coming in for the second pass when the motor suddenly quit. Fortunately the machine crashed into a dense stand of pine and the camera boom absorbed most of the impact with the chopper hanging upside down on the trees a short distance above the ground. The pilot and crew managed to exit with minimal injuries and the cameras also sustained minor damage.

Some three decades later most of this technology is being replaced with drones, digital cameras, lidar and satellite images but I think helicopters are still being used to some extent.


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