A solid-state cockpit-voice recorder (SSCVR) made by AlliedSignal Aerospace, which stores 2h of digitally recorded sound, has received US Federal Aviation Administration certification.
An SSCVR will be required on all Part 121 transport-category aircraft in Europe by April 1997, and AlliedSignal believes that the FAA will require the equipment to be installed in US-registered transport aircraft "...by around the end of the century". The proposed use of the recorder in the USA has also been recommended by the US National Transportation Safety Board.
The SSCVR has been certificated by AlliedSignal's Commercial Avionics Systems (form-erly Sundstrand Data Systems) in Redmond, Washington, to comply with stringent crash-survivability requirements defined by the European Organisation for Civil Aviation Equipment (Eurocae) in 1994. The requirement states that the unit must be able to survive a 10h "low-intensity" fire test.
The requirement was added because, historically, when data from a CVR or flight-data recorder were unrecoverable it was often caused by the effect of a long-term fire or "bake" in the post-crash heat. Data from the recorder were successfully recovered after a 1h high-intensity fire (1,100OC) and a 10h low-intensity bake (260OC) - a requirement which was introduced as a result of several recent accidents, including the Lauda Air Boeing 767-300ER crash in Thailand in 1992
The crash-survivable memory block at the heart of the SSCVR also passed a penetration-resistance test which exposed the unit to around 5,000g for 6.5 milliseconds. The 7kg unit has been designed as a plug-in replacement for existing recorders.
Source: Flight International
