Investigators have yet to disclose preliminary findings from the fatal crash of a Gazpromavia Yakovlev Superjet 100, and have yet to clarify whether an apparent communication on angle-of-attack vane maintenance is relevant to the inquiry.
The Interstate Aviation Committee has started analysing data from the flight-data and cockpit-voice recorders retrieved from the twinjet, which came down about 20km from Lukhovitsy, its point of departure, on 12 July.
“At this stage, it is premature to talk about any deadlines for the completion of the investigation, its results, the causes and circumstances of the incident,” it says.
But Yakovlev appears to have issued a technical advisory on 14 July – two days after the accident – referencing “strict compliance” with the requirements of maintenance manuals when replacing angle-of-attack sensors on the type.
Investigators have not commented on the authenticity of the document, a copy of which has been circulated on social media, or whether it bears any relevance to the crash.
But the document informs that “special attention” must be paid to aligning holes and marks on the component with those on the fuselage, and to ensure that it is re-installed in the place from which it was removed.
It also states that, when performing this work, operators are recommended to exercise dual oversight on quality and completeness – and not have a single specialist perform work on replacing two or more angle-of-attack sensors simultaneously.
Illustrations of the sensor’s alignment are included. Yakovlev adds that it should be contacted if there are queries regarding the execution of work, especially if there is difficulty in identifying missing markings.
The document does not contain a specific reason for its publication and distribution.
None of the three occupants of the aircraft survived after it came down in a forest. Russia’s federal Investigative Committee has stated that the aircraft had taken off having undergone repair work.
