So far it appears French authorities reached their conclusions about the deliberate crash of Germanwings Flight 9525 based solely on cockpit voice recordings (CVR) and ground radar. With no flight data recording, the CVR still accounts for the only official on-board record of what transpired during the some ten minutes between the time the flight’s captain left the cockpit and the point at which the A320 crashed into a mountainside in the French Alps. Now, more than a week after the disaster, officials have begun to wonder out loud whether or not the FDR, made by L3 Communications, survived the impact. Lufthansa German Airlines board member Captain Kay Kratky on March 30 told German TV news show Günther Jauch that he fears the FDR might have incurred irreparable damage in the crash. “It's possible that the impact was too great for the flight recorder and that it doesn't send signals [that would help to locate it at the crash site],” he said.
Kratky’s comments might have raised questions about whether or not the regulation governing damage tolerance of the so-called black boxes goes far enough to ensure the recordings survive such a violent impact. Traveling at some 380 knots, the A320 broke into thousands of pieces, none any bigger than a small car, according to crash investigation officials.
Nevertheless, experts in the field of cockpit flight data and voice recorder technology doubt seriously that the FDR suffered irreparable damage. According to Honeywell technical manager for recorders and data management systems Michael Thompson, even if the memory unit separates from the FDR casing due to an impact that exceeds the standard of 3,400 Gs for 6.5 milliseconds adopted in FAA technical standard order (TSO) C124b, modern forensic methods will virtually ensure retrieval of the data.
“Recorders are such that as long as we get that [memory unit] canister, even if the [memory] chips have become dislodged because of the severity of the impact, the crash investigators want to get every single piece of data from that, and they will go to unprecedented lengths,” he said. “We have the technology that even if we get a bag of chips back, we can download from the individual chip and paste it all back together. Even if the chip is damaged we can take it to the chip manufacturer and do a process called delidding to expose the actual die of the chip, to get to that.”
In fact, the real barrier to retrieving the FDR data lies in the small size of the memory unit, added Thompson. Although the units do contain a beacon for underwater retrieval, they contain nothing to aid a search on land other than their bright orange color. Although the shape of the memory units differs depending on manufacturer, their volume doesn’t generally exceed that of a soda can. “It might just take some time to locate the actual crash module,” he concluded.
In a March 31 statement, France's BEA accident investigation agency explained the main focus of its continuing investigation. It said that investigators are seeking to provide a detailed technical explanation of "the history of the flight," based on detailed analysis of the cockpit voice recorder "as well as any flight parameter data that may be available. BEA is also studying "systemic weaknesses" revealed by the crash, and, in particular, is considering the cockpit door locking system, cockpit access and exit procedures, "as well as criteria and procedures applied to detect specific psychological profiles."