Carrier orders pilots not to tamper with recorder data.

Hong Kong’s Dragonair issued its pilots renewed orders not to erase cockpit voice recorder (CVR) data after an investigation into a turbulence incident found that one of its crew members deliberately did so.

Dragonair A330 Big

The revelation that the CVR had been deliberately tampered with came in a report by Hong Kong’s Civil Aviation Department (CAD) into the 18 July 2003 incident. The Airbus A330-300 was operating between Kota Kinabalu in Malaysia and Hong Kong when it met severe turbulence while cruising within the Manila flight information region. The turbulence lasted 30s, leaving 12 crew members injured, including two seriously.

The investigation found the deviation around weather was not initiated early enough, nor was it large enough to avoid the weather, and determined there was a lack of proper training in the use of the aircraft’s weather radar.

A surprise finding during the probe was that the CVR had been deliberately erased 21min after touchdown. This did not directly affect the investigation because the CVR had only a 30min recording capability and the recording from the time the aircraft met the turbulence had already been overwritten, but it concerned the investigators. At the time the 55-year-old captain and 23-year-old first officer were still on the flightdeck, having left around 7min after the CVR was erased.

“Considering that the ‘Push to Erase’ button can only be activated when the aircraft is on the ground with parking brakes selected ON, it is clear that this was an action on the part of a person who possessed sufficient knowledge of the aircraft systems to be aware of the nature and consequence of such an action,” the report says.

“Although the investigation team was unable to establish the precise reason for the ‘Push to Erase’ input, it can be inferred that this was an attempt to erase the CVR record. This action was in contravention of the company’s instruction with regard to the preservation of flight records.”

Dragonair says its manual “states that neither the CVR nor other recorders should be erased by flightcrew”, but declines to say whether disciplinary action was taken. “The involved crew, together with all our cockpit staff, were issued with a reminder regarding this regulation,” it adds.

The CAD says while it is a legal requirement in Hong Kong for locally registered commercial aircraft to be fitted with CVRs and FDRs, “there is no legal requirement regarding preservation of standalone CVR data”.


Source: Flight International