15 recommendations to improve safety following the crash of the Ju 52
Payerne, 28.01.2021 - The Swiss Transportation Safety Investigation Board (STSB) has published the final report on the crash of the Ju 52 aeroplane near Flims (canton of Grisons, Switzerland) on 4 August 2018. In its report, the STSB concludes that a number of different factors led to the accident. To improve aviation safety, the STSB has issued eight safety recommendations to the supervisory authority and seven points of safety advice to the companies concerned. The investigation does not establish blame or determine liability.
On 4 August 2018, a historic Junkers Ju 52 commercial aircraft known as ‘Iron Annie’, operated by Ju-Air, crashed near Flims in Switzerland. All 20 people on board lost their lives. The STSB investigated the accident in order to identify the cause of the crash.
The STSB published the final report on this accident on 28 January 2021. In its report, the STSB concludes that the pilots’ actions led to the crash. Errors on the part of air operator Ju-Air – as well as negligence by the supervisory authority, the Federal Office of Civil Aviation (FOCA) – contributed to the circumstances in which such an accident could occur.
High-risk piloting was a direct cause of the accident
The STSB established that the pilots’ high-risk flying was a direct cause of the accident. When entering the narrow valley south-west of Piz Segnas, the flight crew piloted the aircraft at low altitude, with no possibility of an alternative flight path and at an airspeed that was dangerously low for the circumstances. As to be expected in the mountains in close proximity to the terrain, the aeroplane flew through turbulences in this valley. The high-risk manner of flying through these not unusual turbulences caused the pilots to lose control of the aircraft. The aeroplane was flying too low to allow enough space to rectify the situation, and as a result it almost vertically hit the ground.
Underlying factors contributed to the accident
In its report, the STSB identifies, among other things, the following underlying factors that contributed to the accident:
- The centre of gravity of the aeroplane was beyond the rear limit during the flight in question. This dangerous situation was caused by inadequate flight preparation and errors in the Ju-Air software.
- The pilots of the accident flight, and also a number of other pilots, had become accustomed – when working for Ju-Air – to not complying with rules for safe flight operations and taking high risks even with passengers on board.
- Ju-Air failed to recognise the significant risks in its flight operations. Furthermore, the air operator failed to prevent its pilots from repeatedly violating the rules.
- Various requirements which are intended to ensure a high level of safety for commercial passenger air transport had not been met for some time.
- FOCA’s supervisory activities failed to identify numerous safety problems at Ju-Air or were ineffective.
Further risks identified and safety recommendations made
In addition to these underlying factors, the STSB identified other risks – including that the aircraft involved in the accident was in improper mechanical condition – however, these did not contribute to the accident.
To improve aviation safety, the STSB has issued eight safety recommendations and seven points of safety advice in its report. The safety recommendations are addressed to FOCA as the competent supervisory authority and are intended to facilitate effective operational and technical supervision. With regards to the safety advice, the STSB is addressing the air operator Ju-Air as well as the aircraft maintenance organisations concerned. The purpose of this advice is to improve operational aspects within the organisations and to help identify and mitigate risks in a more safety-conscious manner.
The Swiss Transportation Safety Investigation Board (STSB) is the independent authority of the Swiss Confederation with the mandate of investigating accidents and serious incidents in civil aviation, navigation and public transport. The sole purpose of STSB’s safety investigations is to gain knowledge that can be used to prevent future accidents and dangerous situations from occurring and to increase safety. Its safety investigations are expressly not intended to establish blame or determine liability.
Address for further information
STSB, Aviation Division +41 26 662 33 00
PublisherSwiss Transportation Safety Investigation Board STSB, Aviation Division