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Coutinho's Method for the Altitude

Published online by Cambridge University Press:  11 December 2019

António Costa Canas
Affiliation:
(Escola Naval and CINAV, Base Naval de Lisboa – Alfeite, Almada, Portugal) (CH-ULisboa, Universidade de Lisboa, Lisbon, Portugal)
Magda Ramires Marabujo
Affiliation:
(Escola Naval, Base Naval de Lisboa – Alfeite, Almada, Portugal)
Teresa Sousa*
Affiliation:
(Escola Naval and CINAV, Base Naval de Lisboa – Alfeite, Almada, Portugal) (Centro de Matemática e Aplicações (CMA), FCT-UNL, Campus de Caparica, Caparica, Portugal)
*

Abstract

In the first aerial crossing of the South Atlantic, by Gago Coutinho and Sacadura Cabral in 1922, several methods of astronomical maritime navigation were used with adaptions to aerial navigation. In order to apply these methods, the navigator needed to know the approximate altitude of the aircraft so that its position could be determined. The instrument available at that time, the altimeter, did not give reliable values for altitude. Therefore, Coutinho had to devise a method that enabled the navigator to determine the altitude quickly and efficiently. The method Coutinho devised is based on a mathematical and geometrical procedure. In this paper, we study in detail Coutinho's method to determine altitude, with diagrams to aid understanding of the deductions and calculations. We also present a real example of how this method would be used during the flight.

Type
Research Article
Copyright
Copyright © The Royal Institute of Navigation 2019

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References

REFERENCES

Anonymous. (1922). Foreword of the memoir ‘Aerial navigation’. Anais do Clube Militar Naval, 52, 361362.Google Scholar
Brown, A. W. (1920). Flying the Atlantic in Sixteen Hours. With a Discussion of Aircraft in Commerce and Transportation. New York: Frederick A. Stokes Company. Available at: http://www.gutenberg.org/ebooks/47129Google Scholar
Canas, A. C., Marabujo, M. and Sousa, T. (2019). O corrector de rumos de Gago Coutinho e Sacadura Cabral. Boletim da Sociedade Portuguesa de Matemática, In press.Google Scholar
Coutinho, G. and Cabral, S. (1922). Aerial navigation. Anais do Clube Militar Naval, 52, 361389.Google Scholar
Coutinho, G. (1923). Relatório técnico sobre a navegação. Relatórios da 1a Travessia Aérea do Atlântico Sul, Revista Aeronáutica (special issue), 130. Available at: https://arquivohistorico.marinha.pt/details?id=11350Google Scholar
Coutinho, G. and Cabral, S. (1927). A navegação aerea. Revista Polytechnica, 8, 384410.Google Scholar
Hawker, H. G. and Grieve, K. M. M. (1919). Our Atlantic Attempt. London: Methuen & Company Limited. Available at: https://archive.org/details/ouratlanticattem00hawkrich/page/n8Google Scholar
Hoüel, J. (1914). Tables de logarithmes à cinq décimales pour les nombres et les lignes trigonométriques. Paris: Gauthier-Villars.Google Scholar
Jones, B. (1931). Avigation. New York: John Wiley & Sons.Google Scholar
Maitland, E. M. (1920). The Log of H.M.A. R34, Journey to America and Back. London: Hodder and Stoughton. Available at: https://archive.org/details/logofhmarjourney00maitrich/page/n5Google Scholar
Pereira, J. M. (2015). Os Céus de Gago Coutinho e Sacadura Cabral. Memórias 2012, Academia de Marinha, Lisboa, 42, 263321. Available at: https://academia.marinha.pt/pt/academiademarinha/Paginas/edicoes.aspxGoogle Scholar
Wimperis, H. E. (1920). A Primer of Air Navigation. New York: D. Van Nostrand Company. Available at: https://archive.org/details/aprimerairnavig00wimpgoog/page/n1Google Scholar