1. Sequence of Flight The reconstruction of ATS surveillance system data may bring to light items of importance in the Operations investigation in relation to the other areas of the occurrence investigation. It may also happen that the particular characteristics of the occurrence necessitate not only the reconstruction of the occurrence flight but other previous flights

2. Although the investigation will have to devote particular attention to the phase in which the event occurred, it will usually be desirable to evaluate the development of the entire sequence of the flight. Display reconstructions can also assist the investigation of occurrences such as near mid-air collisions and provide data for establishing aircraft proximity. The Air Traffic Services investigation should be aware of possible software and display anomalies such as: a) target swapping b) data block swapping c) swapping of target tracks with other aircraft and/or false targets d) incorrect data blocks e) display clutter f) data blocks becoming detached from assigned targets g) displaced target symbols

3. Dependent upon the nature of the occurrence, some or all of the following items may be relevant: a) displays facilities b) symbols c) data blocks, leader lines and orientation d) control settings e) display operator notes f) aircraft identification procedures g) sensor/s inputs h) display mapping i) coverage diagrams j) terrain clearance charts k) SSR code l) system display track number m) system alerts and alarms n) point of closest approach

4. Flight Profile Reconstruction In occurrences such as aircraft proximity violations, mid-air collisions and flight into terrain the Air Traffic Services investigation should establish, record and verify the actual horizontal and vertical flight profiles of the aircraft concerned. Reconstruction will be limited only by information derived from all available recorded data sources obtained by air traffic services or on-board recorded systems where available. The reconstruction should be cross checked with any witness statement/s. s.

5. The selection and availability of data will be dependent upon the particular circumstances of the occurrence being investigated. However, it is most desirable that the investigation examine the original rather than copies of the recorded data wherever possible. It may also be necessary, in certain cases, to have the Operations Group examine and obtain aircraft performance data in order to establish and compare the flight path profile reconstruction with manufacturer’s data and its relevance to the particular circumstance

6. Dependent upon the nature of the occurrence, some or all of the following items may be relevant to the reconstruction of the flight profiles and variations between actual and planned flight profiles: a) horizontal trajectory and deviations b) vertical trajectory, deviations and altitude busts c) rate of climb/descent d) ground speed(s) e) estimated/actual time intervals f) waypoints and geographic graticule

7. ATS Duties and Functions The Air Traffic Services investigation should establish, record and verify all documentation relating to local orders and/or instructions prescribing the duties and functions of all relevant air traffic services operating position/s directly or indirectly involved with the occurrence. The investigation should also consider the effectiveness of the above documentation and the standardization aspects to ensure that communication of relevant information to the aircraft concerned and other relevant Air Traffic Services personnel was accomplished without delay and in accordance with prescribed standard operating procedures.

8. Dependent upon the nature of the occurrence, some or all of the following items may be relevant to each Air Traffic Services officer or workstation connected with the specific occurrence: a) duties and functions b) area of responsibility c) air traffic management responsibilities d) co-ordination responsibilities

9. Work Practices and Staffing It may be desirable because of the circumstances associated with the occurrence for the Air Traffic Services investigation to examine the actual work practices and staffing situation in the period surrounding the occurrence. Where documentation is available, it should be collected and verified. Such documentation should be supported by statements from relevant personnel as appropriate to the circumstances of the occurrence

10. The pertinent work practices and staffing issues relating to the occurrence should be examined with a view to determining whether: a) applicable regulations and standard operating procedures were satisfactory and were adhered to b) differences existed between workload and human resources c) effective use was made of all known and relevant information

11. Dependent upon the nature of the occurrence, some or all of the following items may be relevant: a) prescribed work practices b) actual and required staffing requirements c) licensing and staffing qualifications/requirements d) recency and ratings qualifications/requirements e) initial and continuation training

12. Workstations As well as investigating the operating environment of the aircraft, it is essential that the Air Traffic Services investigation extends to the relevant aeromobile? and associated workstation/s. It will be necessary to investigate not only the efficiency and effectiveness of the Air Traffic Service detailed event transactions and detailed event reconstruction to provide evidence verifying progress of the flight, but also the human machine interface aspects of the system as a whole. In doing so it is important to clearly define the start and ends points for the investigation of the actual occurrence.

13. The Air Traffic Services investigation should establish the operating configuration and ergonomic aspects of the workstation in use in addition to operational information and situational awareness displays. Collection, collation and verification of all relevant elements such as flight progress displays, maps and charts, hardware, software systems, facility controls and presentation are essential items in reconstruction scenarios.

14. Human factors and Ergonomics (HF&E) is a multidisciplinary field incorporating contributions from psychology, engineering, industrial design, graphic design, statistics, operations research and anthropometry. In essence it is the study of designing equipment and devices that fit the human body and its cognitive abilities. The two terms "human factors" and "ergonomics" are essentially synonymous. [ psychologyengineeringindustrial designgraphic designstatisticsoperations research anthropometry cognitive The International Ergonomics Association defines ergonomics or human factors as follows: Ergonomics (or human factors) is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data and methods to design in order to optimize human well-being and overall system performance.

15. It is important to critically examine workstation systems and sub-systems to determine their adequacy in relation to the particular occurrence and possible effects on other similar future events. It may also be relevant to consider the relevance of adequate illumination, workload and distractions in the vicinity of the workstation. Consistency of documentation held by Air Traffic Services personnel and aircrew should be examined, e.g. maps and charts. These aspects should include an assessment of issues which could be forwarded to the Human Factors Group.