However, the official report, published in May 2010, said the crash was due to ‘a combination of circumstances, including a faulty altitude meter and ‘inadequate response’ from the pilots.’

In 2013, the then-transport minister Wilma Mansfeld told parliament that the altimeter had been repaired on 16 occasions in the year before the crash.

Pressure

Former OVV chairman Pieter van Vollenhoven has denied that the report was unduly influenced. ‘The OVV often comes under pressure, but I swear that this has no influence on our reports. We place a great deal of importance on our independence,’ he told Radio 1 news.

Both Boeing and Turkish Airlines were aware of the problems with the alimeters before the crash. ‘You could switch them off by hand,’ he said. ‘That had happened on two earlier flights. Boeing did not therefore see this as a safety problem.’

Delft University aviation expert Joris Melkert also told NOS he did not believe the OVV had allowed itself to be influenced by Boeing. ‘It is quite normal to let everyone involved comment on a draft report,’ he said. ‘The OVV then decides what to incorporate.’