The final report into the Clutha helicopter crash is expected to be published by the middle of next year, air accident investigators have said.
Ten people died and many more were injured after the police helicopter crashed on to the roof of the Clutha pub in Glasgow on November 29 last year.
A progress update from the Air Accidents Investigation Branch (AAIB) today said it has continued to work on establishing the "causes and contributory factors that led to the accident".
An AAIB statement said: "The helicopter was not fitted and not required to be fitted with crash-protected flight data or cockpit voice recorders, and its systems did not provide for the continuous recording of operational parameters.
"As a result, significant work was required to extract and analyse the contents of non-volatile memory (NVM) from micro-chipped equipment known to record data.
"This, together with further examination of the aircraft and subsequent tests, has now been completed to the extent that the investigation team may reach its conclusions.
"Several weeks are still required to complete the draft final report and it is expected that this draft will be circulated to 'interested parties', as defined by the regulations, for comment early in 2015.
"The final report is expected to be published in the middle of 2015."
The update comes as the city prepares to mark one year on from the tragedy with a benefit concert being held tonight to launch the Clutha Trust, to help disadvantaged young people.
A service is also being held at Glasgow Cathedral tomorrow.