CAA report says flightdeck video could yield useful information, but investigators could easily be misled by it
Flightdeck video recorders could provide useful information to air accident investigators, according to research results just published by the UK Civil Aviation Authority. But the CAA cautions that, on its own, image interpretation can be misleading, even to professional investigators.
Following this study, the CAA urges further research into system installation and interpretation of the data, and says there must be a cost-benefit analysis and regulatory impact assessment before any decision is taken to adopt it.
The agency says: "This research has not found CIRS [cockpit image recording systems] to be as effective as has been postulated by some accident investigation agencies." The main benefits of image recorders, it adds, are that, depending on the ambient light, they might show if flightdeck displays have gone blank, and if there is smoke, it might be visible.
The CAA also says: "CIRS can show when a crew has attempted an action and failed to achieve it, for example trying and failing to deploy thrust reversers." This would not show on a flight data recorder (FDR) or, unless the flight crew discussed it, on a cockpit voice recorder (CVR). The CAA says this could prevent erroneous judgements of flightcrew error.
The CAA adds: "If inappropriately installed, CIRS can pose a significant and potentially detrimental intrusion into flightcrew privacy." There are also cost and weight penalties: "Protecting the data...may require changes to the data protection legislation that applies to flight recorders, in the UK and abroad." It adds: "The use of image recorders in isolation could be actively misleading."
The CAA made eight recommendations on CIRS, including that there should be special image interpretation training for investigators, and that the visual data should not be used unless corroborated by CVR, FDR or material evidence.
How the study worked
The CAA installed an FDR, a CVR and an image-recording system on a full-flight simulator and arranged for the crew to "fly" several predefined scenarios that were "designed to lead to serious incidents". The results were analysed in two stages. First, the German air accident investigation agency BFU analysed the FDR/CVR data without access to the image recorder data and the equivalent French agency, BEA, analysed the image recorder data without access to the FDR/CVR data then both the BFU and BEA "were given access to the data that had previously been withheld to determine whether their conclusions changed. The investigators had no prior knowledge of the incident scenarios. The resulting reports were analysed by the CAA to determine whether image recorders did provide useful additional information."