Despite an extensive investigation, aviation experts say they still have not established what caused a Crossair plane to crash shortly after take-off from Zurich a year ago. All 10 people on board were killed.
The second preliminary report into the accident, released on Tuesday, did not shed any further light on what caused the crash of the Saab 340B, two minutes after it left Kloten airport for Dresden in Germany.
Investigators only ruled out the possibility that a fire on board caused the plane to crash.
The report came on the eve of the anniversary of the accident, which will be marked by a special ceremony for relatives and close friends at the site of the crash during which a memorial will be unveiled.
The first report published shortly after the crash said the take-off had proceeded normally. However, seven seconds into the flight the plane veered left although it had been instructed by the control centre to turn to the right.
The plane then spiralled as it nose-dived to the ground.
Investigators hope to conclude their research this August and deliver their final report by the end of the year.
Based on the latest report, the Swiss Aviation Accident Investigation Bureau, has made five recommdenations to the Federal Office for Aviation Security.
The recommendations concern the programming and usage of the flight management system, the usage of the automatic pilot function and the hiring of crew members with foreign licenses.
The families of some of the victims have claimed compensation and are still in negotiations with the airline. Crossair lawyer Gabriele Hofmann said she expected that between SFr2 million and SFr4 million would be awarded in each case, and the total sum paid out will lie around SFr25 million.
The relatives of two of the victims have not requested any compensation.
Crossair said the accident had not had a negative impact on the company. According to a spokesman, Andreas Schwander, the number of reservations increased last year from six million to 6.3 million.
swissinfo with agencies