When using the L-CAS in tests, operators were accurate within 4 inches, even when ladders are extended to distances of 80 and 100 feet. The intuitive system is as effective with all three aerial movement axes. Whether you are extending the ladder, rotating it, booming it in, or a combination of all three, the L-CAS will give you the confidence of knowing exactly how far from the building you are. The L-CAS also increases accuracy when laddering a roof. The operator is able to see exactly when the tip of the ladder has crossed the edge of the roof, as the beams of light will disappear. No more expectations of a six foot aerial overshoot, only to find it overhanging two feet making the transition of the roof much more risky.

The Laser Collision Avoidance System from Command Light, or L-CAS for short, uses laser beams projected from the tip of an aerial ladder to create an intuitive, heads-up indication of distance from the aerial to a structure.

The L-CAS was invented by a veteran firefighter that found that lasers are the best way to artificially create the visual effect he saw when the sun was to his back as he extended the aerial toward a building. The shadow of the aerial climbed the wall of the building, as the aerial extended toward the building, until it met the tip of the aerial as the aerial reached the building. He recognized that the shadow was a perfect indicator of the distance between the tip of the aerial and the building.

When looking down the length of an extending aerial, past about 30 feet, our binocular vision loses ability to perceive distance accurately. In observations of experienced aerial truck operators, or ATOs, this phenomenon produces a typical error in judging the distance from aerial to structure of about 10-15% of the operator's distance from the aerial's target. For example, we saw that when an ATO tries to extend an aerial toward a structure so that the aerial tip stops 6 inches from the structure, he or she is likely to stop 5-6 feet short of the structure at an extension distance of about 50 feet. This error grows to about 10-12 feet short when extending 80 feet, and so on. Under the same conditions, the L-CAS reduced the operator's error in judging these distances to typically 3-4 inches, even at extension distances of 80 to 100 feet.

The L-CAS is as effective to use with all three aerial movement axes so it won't matter if you approach the building while extending the aerial, rotating it, booming it in, or a compound movement including all three. The L-CAS also increases accuracy when laddering a roof. The operator knows the tip has just crossed the edge of the roof when the lasers disappear over the edge of the roof. The ATO then further extends the aerial the distance they want it to overhang the edge. Aerial operators have tested the L-CAS and found they were comfortable with it after only minutes of practice.

An L-CAS unit should be installed on both sides of the tip of an aerial to complete the system. If a unit is placed on one side only, and the aerial is used at an angle leaving the L-CAS on the far side of the aerial away from the wall, the L-CAS will remain too far from the structure to give accurate positioning information for the side nearest the wall.

With the "heads-up" visual nature of the L-CAS, aerial operators need not look away from the tip of the aerial. Other collision avoidance systems, like those based on technology found on rear bumpers of some newer cars, provide a warning indicator on the aerial control panel, requiring the operator to look down away from the target.

Should the L-CAS fail for any reason, say from an electrical short in the apparatus or something, it is immediately recognizable to the operator.

A known limitation of the L-CAS stems from a federal regulation requiring that any laser used in the presence of unprotected eyes be no higher than 5mW in strength. This limitation means that on a bright sunny day, typically most people find the laser projections to be visible on all sides of a structure except the surface in direct sunlight. However, this is also the only surface on the structure that will show the natural shadow of the aerial.