Schweizerische Sicherheitsuntersuchungsstelle SUST Service suisse d’enquête de sécurité SESE Servizio d’inchiesta svizzero sulla sicurezza SISI Swiss Transportation Safety Investigation Board STSB Final Report No. 2370 by the Swiss Transportation Safety Investigation Board STSB on the accident involving the Junkers Ju 52/3m g4e commercial aircraft, HB-HOT, operated by Ju-Air, on 4 August 2018 1.2 km south-west of Piz Segnas, within the municipality of Flims (in the canton of Grisons), Switzerland Swiss Transportation Safety Investigation Board STSB 3003 Bern Tel. +41 58 466 33 00, Fax +41 58 466 33 01
[email protected] www.sust.admin.ch Final report HB-HOT Acknowledgement Observations, photographs and videos provided to the Swiss Transportation Safety Investiga- tion Board (STSB) by citizens during the investigation significantly contributed to the investi- gation and to the final report that is now available. The STSB would like to thank everyone who spontaneously or upon corresponding request provided information and visual material for the investigation. The following authorities, organisations and companies have significantly and in an exemplary manner contributed to the success of the investigation: The Bureau d’Enquêtes et d’Analyses pour la Sécurité de l’Aviation Civile (BEA) Zurich Forensic Science Institute (FOR) The cantonal police of Grisons The municipality of Flims Flims Electric AG, Flims (canton of Grisons) MatExpert GmbH, Thun (canton of Bern) Mountain Lodge, Segnes pass Zurich University of Applied Sciences (ZHAW) Swiss Transportation Safety Investigation Board Page 2 of 78 Final report HB-HOT General information on this report In accordance with Article 3.1 of the 12th edition of annex 13, effective from 5 November 2020, to the Convention on International Civil Aviation of 7 December 1944 which came into force for Switzerland on 4 April 1947, as amended on 18 June 2019 (SR 0.748.0); Article 24 of the Federal Act on Civil Aviation of 21 December 1948, as amended on 1 Jan- uary 2020 (CAA, SR 748.0); Article 1, point 1 of Regulation (EU) No.