Recorder Conundrum

Greek investigators struggling to determine the cause of the Helios Airways crash near Athens are, at this point, facing two problems: the flight data recorder (FDR) has not been recovered, and the cockpit voice recorder (CVR) only captures the last 30 minutes of audio. It may not reveal much, as the airplane flew for hours after the pilots were apparently disabled, so the most wanted information may have been overwritten.

These problems have spurred some to call for a means to transmit FDR and CVR data to the ground every few seconds. While this may be technically feasible, unless it is mandated by the Federal Aviation Administration (FAA), it is unlikely to be widely adopted.

Under the almost now consolidated FAA plans to revamp data recorders, there is no provision for mandating any real-time data transmission and collection. Ejectable crash recorders seems about as far as the FAA is likely to go (see ASW, Aug. 1). If one looks back at the accidents of the last ten years, only about 50 percent of the recorders have provided usable post-crash data. This failure rate is attributable to:

• Insufficient parameters recorded.
• Black box destroyed or not recovered.
• Sampling rates too highly filtered.
• CVR data over-recorded.
• FDR and CVR have proven to be unserviceable for a protracted period.
• Pilots intentionally failing to pull (or resetting) circuit breakers in order to delete data.
• CVR open microphone data unintelligible.

Cockpit cameras are being opposed by pilots, and the FAA has not mandated them. Externally mounted cameras may happen in time, but likely at the election of the operator and not mandated by the FAA.