Frequency and severity of deviations during simultaneous independent approaches to parallel runways

Feasibility analyses for paired approach procedures for closely spaced parallel runways

“…A separate, unpublished, analysis of data from 2009, otherwise reported in [11,12], shows that for the 305,217 approaches to independent parallel runways observed in that study, no lateral deviation occurred closer than 3.7 nmi from the threshold 2 . Two cases were therefore examined in this study: first, that blunders might occur anywhere along the final approach path, and second, that blunders would not occur inside the final approach fix.…”

“…Recent analyses [11][12][13] have yielded empirical values for p(blunder per approach). Monte Carlo techniques have been used to determine values for p(collision | blunder), window sizes that meet an acceptable TLS, and procedure feasibility.…”

“…Monte Carlo techniques have been used to determine values for p(collision | blunder), window sizes that meet an acceptable TLS, and procedure feasibility. Table 1 has been produced with data from [11]- [13]. The study examined deviations resulting in no transgression zone (NTZ) violations and examined a total of 785,203 instrument approaches from 12 airports from October 2007 through June 2009.…”

“…For the purposes of this paper, these NTZ violations are also considered to represent blunders for CSPR operations. Data from References [11][12][13] In order to achieve a rate of 10 -9 collisions per approach, based on the data presented in Table 1, the blunder to collision rate must be kept to a value of 10 -4 or less. For the purposes of this study, the factor of 4 in the NTZ penetration rate is ignored as it is believed that there is uncertainty in the first significant digit.…”

Considerations on aviation standards for simultaneous independent and dependent parallel approaches

“…To reduce complexity we assumed initially that those errors are contained in the statistical error distributions of aircraft around their nominal path for RNP approaches (Total System Errors, TSE). For ILS precision approaches we considered blunder probabilities that were obtained from studies in the United States [11]. However it must be noted that DLR's concept will be extended with regard to a thorough analysis of non-normal events that might influence the blunder probability and severity.…”