1. U.S. OPERATIONAL
2. The wind model used for simulation consists principally of 1) steady or constant wind component, 2) a logarithmic wind shear component 3) turbulence component and 4) heading. Wind magnitude and direction were considered to be independent random variables. The source of the total wind magnitude i s the reference wind magnitude probability distribution shown i n Figure 8. This wind magnitude, V i s referenced a t 20 ft. above the ruaay altitude. The total wind magnitude Vw i s decomposed into i t s body axis components UW, VW and WW namely the horizontal, lateral and vertical components. In order to simulate the wind turbulence the mean wind must be calculated as a function of the mean reference wind and altitude. The wind model used i s defined i n Ref. 2. 2000 4000 6000 8000 10000
3. The 767 Monte Carlo autoland simulation touchdown performance i s presented i n Figures 11-18. The histograms and cumulative probabi 1i t y distributions represent 1500 simulated autolands i n the stochastic environment previously discussed. Triple channel autopilot, active autothrottle with gears and flaps down were employed. Figures 11 and 12 show the statistics for the longitudinal touchdown dispersion. The 1ongitudinal touchdown statistics i s referenced from the runway threshold and includes variations i n the glideslope transmitter location with mean of 1075 ft. and RMS of 91 ft. The distribution i s approximately Gaussian * to k20 but deviates slightly at the tails. Figures 13 and 14 show the lateral touchdown dispersion. This distribution i s very closely Gaussian as seen i n Figure 14. Based on FAA autoland certification criteria shown i n Figure 19 the 1ongitudinal and 1ateral touchdown dispersion statistics are well within the performance requirements as defined i n Reference