Abstract: A dynamometer for a snowmobile includes a pair of driver wheels which replace the tension idler wheels so as to contact the inside of the snowmobile track. The regular snowmobile tension idler wheels are removed, and the driver wheels are positioned on the idler wheel axle. In the alternative, the dynamometer is attached to the existing tension idler wheels by a coupling plate. In the alternative embodiment, the tension idler wheels are configured for power take off by including pins forming a quick connect coupling mechanism. The quick connect coupling mechanism permits the dynamometer to be connected to the snowmobile without having to remove and replace the tension idler wheels with a different pair of driver wheels. A jack is provided to lift the snowmobile track clear of the ground by applying a lifting force between the ground and the tension idler wheel axle. The dynamometer and jack are integrated so as to share common components.

Abstract: The invention is an electronic system for warning helicopter pilots of the presence of electric power lines during landing. The system detects electromagnetic fields created by electricity flowing through the power lines. When the helicopter is closer than a predetermined distance from the power line, visual and audio alarms alert the pilot of the danger. When the helicopter is a safe distance from the power line, the alarms reset.

Abstract: A variable Venturi slide includes a beveled edge at an oblique angle to lower surface of the slide and air flow, and an auxiliary hole having an opening on the beveled edge communicating between the air flow and the interior of the variable Venturi slide. By being located on the beveled edge, the opening of the auxiliary hole is effectively kept out of the high velocity low air pressure air stream at lower air velocities during partial throttle conditions. The auxiliary hole bleeds vacuum from the interior of the variable Venturi slide, picked up by the other lift hole located on the bottom of the slide, and slows the slide lift rate. The slide stays down or rises very slowly under conditions in which a conventional prior art slide would be starting to rise at a linear rate. At higher air velocities, when the throttle plate is opened quickly or operated at near wide open conditions, the opening of the auxiliary hole adds vacuum to the interior of the slide, and increases the slide lift rate.