Effectiveness of Helicopters in Fighting Forest Fires in Türkiye: A Data Envelopment Analysis Approach

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Cancel the red color in the text, check the article according to the instructions for authors.

Illegible image 1.- improve image quality.

Modification of formulas 1 to 5 remodel.

Fig. 2,3,4,5 modify according to the authors' instructions.

Literature, correct as instructed, add at least 10 more references on the subject.

State the limitations or weaknesses of DEA analysis when describing DEA in the paper.

Tables and figures do not have a source listed.

It is possible to specify costs in more detail to confirm the authors' assertion that there would be cost reductions in domestic production within Turkey.  Please state in the conclusion of the paper.

After these corrections, I recommend to publish.

Author Response

we would like to thank you very much for your contribution and advice to our study. Your guidance and suggestions are very important for this study. Below the changes made according to the reviewers’ suggestions are listed: 

Comment 1: Cancel the red color in the text, check the article according to the instructions for authors.

Answer 1: Red color in the text have been corrected and the rules have been followed.

Comment 2: Illegible image 1.- improve image quality

Answer 2: Image 1 has been re-added in higher resolution.

Comment 3: Modification of formulas 1 to 5 remodel

Answer 3: The error in the formula from 1 to 5 has been corrected.

Comment 4: Fig. 2,3,4,5 modify according to the authors' instructions.

Answer 4: Figures 2,3,4,5 have been modified according to the authors' instructions.

Comment 5: Literature, correct as instructed, add at least 10 more references on the subject.

Answer 5: Since there are not many studies in the literature in the field of firefighting helicopters, few references were given at first, but 10 more references were added as called. (Lines 57-86)

Comment 6: State the limitations or weaknesses of DEA analysis when describing DEA in the paper.

Answer 6: weaknesses of DEA analysis are described. (Lines 184-194)

Comment 7: Tables and figures do not have a source listed.

Answer 7: references of tables, data in tables and figures have been added.

Comment 8: It is possible to specify costs in more detail to confirm the authors' assertion that there would be cost reductions in domestic production within Turkey.  Please state in the conclusion of the paper.

Answer 8: Information on domestic production costs is provided in the conclusion section.

We appreciate the reviewer’s insightful comment. In response, we have revised the Conclusion section to include a more detailed justification of the cost reduction potential associated with domestic helicopter production in Türkiye. We have incorporated relevant international literature that demonstrates significant cost disparities between different aerial firefighting assets. Specifically, we cited Keating et al. (2012), who found that scoopers incur markedly lower annual operational costs than airtankers or helicopters, and Hartsough et al. (2008), who identified cost-efficiency advantages in helicopter-based mechanical treatments. Drawing from these studies, we argue that similar cost-saving mechanisms may be realized through domestic production and localized logistics in Türkiye. The revised paragraph is located in the Conclusions section, immediately following the discussion on long-term operational efficiency and national fleet development. (Lines 366-368)

Reviewer 2 Report

Comments and Suggestions for Authors

From the title of the paper, the reviewer expected a discussion on the effectiveness of helicopters with various performances in aerial firefighting, but the content of the paper was only a discussion on the performance evaluation of “helicopters used for aerial firefighting”. Although this paper is not directly related to firefighting, it could indirectly help in the construction and development of an aerial firefighting strategy. However, in the manuscript, the authors point out that only Sikorsky T70 needs to be improved, which is not an interesting result. In addition, other helicopters were analyzed but not discussed at all.

Before this paper is published in FIRE, the authors should add a discussion in the text, rather than a conclusion, of the differences in firefighting performance of each helicopter and the differences in firefighting strategies when using water buckets versus water tanks.

One minor point that should be corrected is that the resolution of the image in Figure 1 is very low and the characters in the figure is not clearly visible.　

Author Response

Comment 1: From the title of the paper, the reviewer expected a discussion on the effectiveness of helicopters with various performances in aerial firefighting, but the content of the paper was only a discussion on the performance evaluation of “helicopters used for aerial firefighting”. Although this paper is not directly related to firefighting, it could indirectly help in the construction and development of an aerial firefighting strategy. However, in the manuscript, the authors point out that only Sikorsky T70 needs to be improved, which is not an interesting result. In addition, other helicopters were analyzed but not discussed at all.

Response 1: In Turkey, both airplanes and helicopters are used in aerial firefighting. This study is a specifically focus on helicopters. The authors performed similar study on airplanes, and it is in publication process. Corrections were made and other helicopters were discussed. We appreciate the reviewer’s valuable feedback. In response, we revised the Discussion section to include a practical interpretation of the DEA results. We now discuss the operational strengths of fully efficient models such as the CH-47 Chinook, Kamov Ka-32, and Airbus H215 in different firefighting scenarios. This addition highlights the contextual effectiveness of each helicopter and better aligns the analysis with the paper’s title and practical relevance. (Lines 322-337)

Comment 2: Before this paper is published in FIRE, the authors should add a discussion in the text, rather than a conclusion, of the differences in firefighting performance of each helicopter and the differences in firefighting strategies when using water buckets versus water tanks.

Response 2: We appreciate the reviewer’s insightful recommendation. In response, we expanded the Discussion section to include a detailed comparison of the firefighting effectiveness of the helicopter models analyzed, with a focus on their tactical suitability for different fire scenarios. Additionally, we introduced a paragraph that contrasts the operational characteristics and strategic applications of external water buckets (e.g., Bambi Buckets) and internal water tanks. These additions provide a clearer link between technical efficiency and real-world firefighting performance, as suggested. (Lines 337-351)

Comment 3: One minor point that should be corrected is that the resolution of the image in Figure 1 is very low and the character in the figure is not clearly visible.　

Response 3: The resolution of the image in Figure 1 has been improved. the necessary correction has been made.

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors, 
first of all, I would like to thank you for the opportunity to read your article. 
The article addresses the important and timely topic of the effectiveness of helicopters in extinguishing forest fires in Turkey, using the Data Envelopment Analysis (DEA) method. The topic is interesting and of practical importance in the context of combating climate change and the growing number of fires. Nonetheless, the article needs a number of corrections, both editorial and methodological, before it can be accepted for publication.

1. Abstract -  presents the main aim of the study (to evaluate the efficiency of helicopters used in forest firefighting in Türkiye), the applied methodology (Data Envelopment Analysis), and the key findings. It also includes policy recommendations such as balanced use of Bambi Buckets and internal water tanks, as well as investment in domestic helicopter production. However, it implies that both water delivery systems were quantitatively assessed within the DEA framework, which is misleading—these aspects are only addressed qualitatively. The abstract should be revised to better reflect the actual scope of the DEA analysis, which is limited to technical and operational helicopter parameters.
2. Introduction - provides a solid contextual background, discussing the growing threat of forest fires in Türkiye, exacerbated by climate change, and outlines the strategic importance of aerial firefighting. It also presents regional fire risks, various firefighting methods, and compares two main helicopter-based water delivery systems: Bambi Buckets and internal tanks. While the structure is clear and references are current, there are significant issues with Figure 1 (fire risk map): the figure lacks a legend, color explanation, and source citation.
3.  Methodology is well-constructed and provides a clear justification for the use of DEA, particularly the input-oriented BCC model, which allows for evaluation of varying scales and capacities among helicopter models. The input and output variables are appropriately selected and defined. However, the article lacks transparency regarding the source of technical data (e.g., fuel consumption, rotor diameter, service ceiling) and fails to mention the software or tool used to perform the DEA computations. These details are essential for reproducibility and must be clarified.
4. Findings presents the DEA results in a logical and interpretable manner, highlighting that most helicopter models operate at full efficiency, except for the Sikorsky T70, which demonstrates room for improvement. The analysis includes several graphical representations (Figures 2–7) comparing technical efficiency, fuel consumption, and potential savings. However, the visual presentation is lacking in clarity: most figures are missing legends, axis labels, and explanations of symbols or colors (e.g., “pink markers” and “gray markers” are mentioned but not labeled in the figures). A summary table of individual DEA scores (θ values) for each model would significantly improve the readability and transparency of the findings.
5. Conclusions  are consistent with the analysis and provide actionable recommendations, particularly concerning operational optimization and investment in domestic helicopter production. The authors emphasize the importance of balancing different water delivery systems, though this conclusion is largely based on descriptive content rather than quantitative comparison. While the conclusions are reasonable, the study would benefit from a brief discussion of limitations or potential sources of error in the analysis.
6. References -  list includes recent and relevant sources covering forest fires, aerial firefighting, and DEA methodologies. However,  formatting issue should be checked. 

I have underlined some detailed comments below:

• Figure 1 - Fire risk map:
  The article references Figure 1 (“Black areas in Figure 1 have the highest fire risk...”), but the map itself is not properly placed in the document. The proper caption, legend and data source are missing.
• The charts (Figure 2-7) clearly show the results of the efficiency analysis, with particular emphasis on the Sikorsky T70 helicopter as needing optimization.
  Legends for some of the charts are missing, and the colors and point designations are undescribed (e.g., “pink markers” or “gray markers” have no explanation in the caption).
  The charts should be better embedded in the text - with clear references and interpretive commentary.
• Table 1 no reference to data sources
• equation 1-5 missing symbol explanation.

In summary, the article is interesting but still needs some work so that readers can appreciate the effort put into the data. 

Thank you again for the opportunity to read your article. 

 

Author Response

We would like to thank you very much for your contribution and advice to our study. Your guidance and suggestions are very important for this study. Below the changes made according to the reviewers’ suggestions are listed: 

Comment 1: Abstract -  presents the main aim of the study (to evaluate the efficiency of helicopters used in forest firefighting in Türkiye), the applied methodology (Data Envelopment Analysis), and the key findings. It also includes policy recommendations such as balanced use of Bambi Buckets and internal water tanks, as well as investment in domestic helicopter production. However, it implies that both water delivery systems were quantitatively assessed within the DEA framework, which is misleading—these aspects are only addressed qualitatively. The abstract should be revised to better reflect the actual scope of the DEA analysis, which is limited to technical and operational helicopter parameters

Response 1: We appreciate the reviewer’s insightful recommendation. This analysis is limited to the technical and operational parameters of the helicopters and we introduced a paragraph that contrasts the operational characteristics and strategic applications of external water buckets (e.g., Bambi Buckets) and internal water tanks. 

Comment 2: Introduction - provides a solid contextual background, discussing the growing threat of forest fires in Türkiye, exacerbated by climate change, and outlines the strategic importance of aerial firefighting. It also presents regional fire risks, various firefighting methods, and compares two main helicopter-based water delivery systems: Bambi Buckets and internal tanks. While the structure is clear and references are current, there are significant issues with Figure 1 (fire risk map): the figure lacks a legend, color explanation, and source citation.

Response 2: Suggested revisions have been made in the manuscript and figures are updated. 

Comment 3: Methodology is well-constructed and provides a clear justification for the use of DEA, particularly the input-oriented BCC model, which allows for evaluation of varying scales and capacities among helicopter models. The input and output variables are appropriately selected and defined. However, the article lacks transparency regarding the source of technical data (e.g., fuel consumption, rotor diameter, service ceiling) and fails to mention the software or tool used to perform the DEA computations. These details are essential for reproducibility and must be clarified.

Response 3: Fuel consumption, rotor diameter, service ceiling) references have been added. The software or tool with which DEA calculations were performed is indicated. The DEA computations were conducted using the R programming language, ensuring reproducibility and flexibility in model implementation. (Lines 173-175) The table was created by the authors using the data obtained from the related web sources which are referred in the table.

Comment 4: Findings presents the DEA results in a logical and interpretable manner, highlighting that most helicopter models operate at full efficiency, except for the Sikorsky T70, which demonstrates room for improvement. The analysis includes several graphical representations (Figures 2–7) comparing technical efficiency, fuel consumption, and potential savings. However, the visual presentation is lacking in clarity: most figures are missing legends, axis labels, and explanations of symbols or colors (e.g., “pink markers” and “gray markers” are mentioned but not labeled in the figures). A summary table of individual DEA scores (θ values) for each model would significantly improve the readability and transparency of the findings.

Response 4: We would like to thank for this suggestion. In the revised paper, we have added a new bar chart that clearly presents the BCC, CCR and scale efficiency scores for each helicopter model in numerical form. We believe that this visualization effectively serves the same purpose as the requested summary table (Lines 209-220)

Comment 5: Conclusions  are consistent with the analysis and provide actionable recommendations, particularly concerning operational optimization and investment in domestic helicopter production. The authors emphasize the importance of balancing different water delivery systems, though this conclusion is largely based on descriptive content rather than quantitative comparison. While the conclusions are reasonable, the study would benefit from a brief discussion of limitations or potential sources of error in the analysis.

Response 5: We thank the reviewer for highlighting the need to address methodological limitations. In response, we have added a dedicated Limitations paragraph at the end of the Conclusion section. This paragraph outlines the constraints related to variable selection, data quality, and the static nature of the DEA model, while also suggesting directions for future research such as the use of dynamic or stochastic DEA frameworks and real-time operational data. (Line, 420-429)

Comment 6: References -  list includes recent and relevant sources covering forest fires, aerial firefighting, and DEA methodologies. However,  formatting issue should be checked. 

Response 6: References have been checked. Rewritten according to journal format.

Comment 7: Figure 1 - Fire risk map: The article references Figure 1 (“Black areas in Figure 1 have the highest fire risk...”), but the map itself is not properly placed in the document. The proper caption, legend and data source are missing. 

Response 7: the necessary correction has been made according to suggestion.

Comment 8: The charts (Figure 2-7) clearly show the results of the efficiency analysis, with particular emphasis on the Sikorsky T70 helicopter as needing optimization. Legends for some of the charts are missing, and the colors and point designations are undescribed (e.g., “pink markers” or “gray markers” have no explanation in the caption).
The charts should be better embedded in the text - with clear references and interpretive commentary.

Response 8: the necessary correction has been made according to suggestion.

Comment 9: Table 1 no reference to data sources

Response 9: Data sources for each helicopter is given in the reference column.

Comment 10: equation 1-5 missing symbol explanation.

Response 10: Equations 1-5: Explanations of symbols have been added

Comment 11: In summary, the article is interesting but still needs some work so that readers can appreciate the effort put into the data

Response 11: Thank you for the suggestion, relevant corrections have been made per reviewers' suggestions and presented for your kind evaluation.  

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The authors responded appropriately to the reviewers' comments and revised the paper. The revised paper is considered to provide useful information related to aerial firefighting for large forest fires. Based on the above considerations, the revised paper can be judged worthy of publication in FIRE and should be accepted.

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors,

thank you very much for the corrections.

best wishes