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

presented in table 2. Aircraft executed 30-degree localizer
intercepts approximately 3 nautical miles (nmi) from their
respective GSI point.
TABLE 2.
DIA ILS RUNWAY TURN-ON ALTITUDES
Runway Outer Marker Turn-On Glide Slope
(nmi) Altitude (ft) Intercept (mi)
16 4.5 10,000 14.36
17R 4.9 11,000 17.5
17L 4.8 9,000 11.21
Although minor differences between touchdown zone elevations are
planned for the runways at DIA, the simulation used a common
touchdown zone altitude for all three runways because of current
limitations in the simulation capabilities of the Target
Generation Facility (TGF). GSI points also varied from the
actual DIA operation due to the common touchdown zone elevation.
The MPAP TWG and representatives from the Northwest Mountain
Region and DIA concurred that the differences were minimal and
would not affect controller performance.
Approach plates were produced based upon the simulated airport
configuration (see appendix E). The approach plates included
runway layouts, spacings, and arrival frequencies. All flight
simulator approaches in the simulation were made using these
approach plates.
2.1.3 Blunders.
Aircraft blunders were used to test the controllers' ability to
maintain a 500 ft distance between aircraft during critical
situations. During each run of the simulation, blunders
transpired without warning to the controllers. A blunder
occurred when one aircraft, established on the ILS localizer
approach, made an unexpected turn towards a second aircraft on an
adjacent approach course.
In normal operations, the controller detects the deviation of the
blundering aircraft, issues instructions to resolve the
situation, and the pilot verbally responds and complies as
instructed. However, in some situations, the blundering aircraft
may be unable to correct its deviation and may pass through the
NTZ, and cross the adjacent approach course. This inability to
correct the blunder can arise from several causes (e.g.,
communications, hardware failure, human error, etc.). To
simulate this situation, pilots of blundering aircraft were
7