The Influence Factors Analysis of Balanced Field Length Based on Local Sensitivity

Abstract

Balance field length is one of the important technical indexes in civil aircraft design and operation, and it has an important influence on civil aircraft economy, safety and universality, and also determines the aircraft decision speed. The concept and calculation method of balance field length and the relation between balance field length and decision speed are introduced, as well as three sensitivity analysis theories are list. Taking a civil aircraft as an example, the effects of takeoff weight, airport height, wind speed, temperature, runway slope and other factors on the balance field length is studied. The sensitivities of different factors to balance field length are calculated based on the above three analysis theories. The results show that the length of balance field and the decision speed increased with the increase of takeoff weight, airport height, tailwind speed and temperature. They decreased with the increase of headwind speed. The effect of runway slope on the balance field length could be negligible. The positive and negative correlations of those parameters obtained by the sensitivity analysis methods are consistent, and the sensitivity values of the five variables are ranked as follows: takeoff weight> wind speed> airport height> temperature> runway slope.

Keywords

• civil aircraft
• balanced field length
• decision speed
• local sensitivity