Published Report (DOT/FAA/CT-94-36)

5.3.2 Technical Observer Assessment.
The technical observers concluded that the triple approach
operation at DIA could be conducted safely, based upon their
observations of controller and system performance. The technical
observers reported that controllers had little difficulty
detecting and resolving blunders for this operation. It was
noted that the controllers used the F'MA alerts to their
advantage, and often used the additional lead time in determining
the optimal evasion maneuver.
5.3.3 TWG Assessment.
Based on the established test criteria, the TWG concluded that
the controllers met the simulation objective. The arrival
monitor positions in the simulation proved to be operationally
effective and feasible.
Based on the results of the simulation, the TWG concluded in its
operational assessment (appendix K) that the proposed triple
simultaneous ILS approaches at DIA are acceptable, achievable,
and safe with the FMA system and an appropriate radar system,
such as a Mode S monopulse system or an ASR-9 system enhanced to
provide improved target resolution capabilities.
Based on their operational assessment, the MPAP TWG made three
recommendations: 1) there should be one monitor controller for
each runway; 2) monitor positions should be located adjacent to
one another; 3) a radar system with 2.7 milliradians azimuth
accuracy or better and the capability to resolve two aircraft at
20 nmi separated by 0.9 degrees or more should be used.
5.4 RISK ASSESSMENT.
A risk assessment was conducted on the data from the simulation.
Since there is no recorded operational data about blunders, this
analysis determined a target risk value, and then computed a
blunder rate which would result in the target risk value. This
assessment was based on NTSB data for the total number of air
carrier accidents, as well as the number of fatal accidents on
final approach. A risk model was developed, and it was
determined that about ten 30-degree blunders per 10,000 triple
parallel simultaneous approaches could be tolerated for the risk
of the operation to meet the target risk level. Thus, the risk
assessment indicated that the DIA operation meets the target risk
of 4 x lo-' approaches.
6. CONCLUSIONS.
This simulation tested the controllers ability to effectively
resolve conflicts for the proposed triple simultaneous instrument
landing system (IS) operation at the new Denver International
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