Question: The maximum certificated weight of my airplane is 1,800 pounds. I plan to take off with a weight of 1,890 pounds. How does that increase my risk of having a problem during takeoff?
Answer: Attempting to fly an overweight airplane is never advisable as it is both risky and could result in a violation of 14 CFR 91.9 and 91.13. Excess weight negatively affects many aspects of airplane performance. For instance, the increase in takeoff run can be determined by the present weight divided by the maximum certificated weight, squared. In this example, a pilot will experience an increased takeoff run by a factor of (1,890/1,800)2, or 1.052. The result is a takeoff run that is increased by 10 percent. That 10 percent could make a critical difference in the success or failure of a takeoff attempt. Read about the tragic effect of weight on aircraft performance in this accident report from the Air Safety Institute.