What is the straight edge method used for and how does it work?

• A. It is used to determine the height of an obstacle; place a pen at the base of the obstacle, flip it horizontally, and count the pen length as the height
• B. It measures the distance to the obstacle using a string
• C. It determines wind speed using a straight edge
• D. It calibrates radio range using a straight edge

Answer: (A)

The straight edge method is a quick field way to estimate obstacle height using a simple ruler-like reference. You place a pen (or another known-length marker) at the base of the obstacle and look along a straight edge to the top. By flipping the edge horizontally and aligning it again with the top, you can read off how many pen-lengths fit from base to top. That count gives a rough height estimate in those units. This technique is valuable in LZ/PZ work because it requires minimal gear and can be done quickly to gauge clearance and plan safe rotor paths. It’s a handy, low-tech way to get a usable height estimate when more precise instruments aren’t available.