Weight and Balance


Flight testing has shown that the Lazair is very tolerant or changes to the position or the center-of-gravity. However, for comfortable hands -off flying at a reasonable airspeed. and for assurance that there is no gross error effecting the center-of-gravity, the check outlined below is recommended with the center-of-gravity positioned as desired, the Lazair should trim out hands-off at approximately 25 to 28 ~H indicated airspeed.

With the seat positioned as indicated in the Assembly Instructions, the pilot sits very near the center-of-gravity, so reasonable differences in pilot weight do not have an appreciable effect on the position or the pilot’s feet, or even the type or shoes he is wearing. Minor in-night adjustments to the position or the centre-of-gravity can be made by just moving the position or your feet. Also, there will be an effect from the weight or the fuel, so it is recommended that the following check be made with the fuel tank approximately half full.

With the aircraft on the ground and the pilot sitting in the seat in the normal (or most comfortable) seating position, raise the tail until the boom is level (use a spirit level). Hold the aircraft in this position with a bathroom scale under the spreader (T115). The reading on the scale should be between I and 5 pounds. If the aircraft meets this requirement it is adequately balanced for the first test fight (If possible the first fight should be made by an experienced Lazair pilot who is capable or recognizing any unusual flight characteristics). Fine tuning or the balance is best done by flying the aircraft and adjusting the centre-of-gravity for hands-on trim at the power setting and airspeed preferred by the pilot.

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