Simple en route air sector: aircraft of the same type on two flight paths that intersect but are vertically separated and so for whom no conflict exists. Cabin pressure loss can occur on either flight path, and the corresponding flight will make an emergency descent to FL100. No divert occurs (i.e. aircraft remains on original flight path) as no airports are included. Single risk hotspot defined by intersection of new flight path after emergency descent by aircraft from higher flight path to emergency flight level. No specific resolution rules / activities created for controllers (RAMS Plus defaults used).
The purpose of this stage was to provide us with a test ground to test that our search harness would find incident hotspots. This stage has now been completed with some rather unexpected results! As predicted, the search algorithm was able to manipulate aircraft entry times on the low level flight path to the sector to coincide with the aircraft undergoing the emergency event.
However, we have adapted the range of mutation permitted by the search algorithm from selecting an aircraft start time at random within the time span of the simulation (unrealistic but easier to verify the search as working correctly), to a slot-based mutation scheme which takes account of wake turbulence for aircraft following a given flight path. The slot-based scheme is something that directly affects the freedom of the algorithm to explore the available search space, but it is typical of the sort of restrictions necessary to make the model’s implementation more realistic and relevant to the work of safety-related ATM.
Stage 2 is now under way and is much more complex, with further issues around the resolution of the emergency aircraft. We will post more details soon!