Vulnerability and Resilience Analysis of the Air Traffic Control Sector Network in China
Round 1
Reviewer 1 Report
The topic and its significance are of importance to the field. A well written paper overall.
My suggestions are as following:
- The abstract can be improved to be clearer (Sustainability and resilience are highlighted rather than vulnerability and resilience).
- In aviation, terms such as complexity, vulnerability and sustainability have various dimensions. These should be set out clearly in the beginning of the paper and for the specific study and on ATC. Page 2, 68-82 is good and can help to this end (e.g. bring up front). Also, helpful explanations come later (page 5, 167) that could be introduced earlier in the paper.
- Consistency and clarity in terms as these can mean different things in other areas of aviation (e.g. in safety). In addition, authors are advised to be consistent w/re to terms such as: sector, air sector, air sector network, etc. are all used in the paper.
- The sustainability element comes in the beginning (only mentioned) and in the end. The link to sustainability needs to be stronger w/re to the focus of the paper, i.e. vulnerability and resilience.
- Clarify and/or substantiate implications such as: page 1, 34- safety concerns, page 2, 45-46 complex network theory can be more critically discussed. Any limitations? This should also be revisited in the end in light of the findings (since it is also one of the key contributions of the paper).
- Better/stronger/clearer substantiation of use of past studies, especially the transferability from studies on rail used/cited (e.g. page 4, 154). Better substantiation of proposed parameters.
- Sections 2.3 onwards can be better linked to 2.2. which sets out CASN characteristics.
- Limitations should be at least discussed in the end of the paper and suggest further research avenues in light of these.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This paper applies the complex network theory to a model of the ATC sector network of mainland China, according to the flight data on May 1, 2015, where the sector was considered as the nodes and the flight relationship between the sectors as the edges, and examines a series of characteristic parameters with an empirical analysis on its vulnerability and resilience.
The paper is interesting and provides an alternative perspective to investigate the air traffic systems, which potentially enriches the toolkit for decision-makers and stakeholders to better understand its complexity and improve air traffic management.
However, all conclusions are based on none-day flight data. Assuming that the behavior of the Chinese air sector network is that obtained on a given day is very risky, even more so, when nowhere is it specified that this day is a representative day of what usually happens on any day of the year.
The authors must apply the new approach to a sufficiently large number of days to perform a statistically significant vulnerability and resilience analysis of the air traffic control sector network in China.
Minor mistakes:
- Line 155. Change “Clustering coefficient” to “Local clustering coefficient”.
- Line 155. Ei is not clearly defined. Change “Ei” to “\sum_{j,m}aijajmami “.
- Line 155. Change “flow of sectori” to “flow of sector i”.
- Line 155. Change “Where the total number of sector is ,” to “Where the total number of sector is N”.
- Line 215. Change “From the equation (11)…” to “From the equation (3)…”.
- Line 295. Change “0.9947) .” to “0.9947).”
- Line 300. Change “0.9) .” to “0.9).”
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The authors have tried to consider all my comments. Unfortunately, the most important one for me could not be considered due to lack of data. However, they have decided to explicitly highlight this limitaion in the paper. Therefore, my decision is to accept it, because it is clear what the main objective and limitations of the paper are.
