January 14, 2014
A European Aviation Safety Agency draft rulemaking tackles a series of recommendations from accident investigators and working groups that call for beefed- up standards and maintenance practices for aircraft flight and data recorders (FDR).
The key changes would mandate higher-capacity cockpit voice recorders (CVR) on large aircraft, ban “obsolete recording technologies,” such as magnetic tape, and improve post-crash location broadcasting capabilities.
Under the proposed rule, outlined in a Notice of Proposed Amendment (NPA) released last month, large aircraft—defined as having a maximum takeoff weight (MTOW) of at least 27,000 kg. (59,500 lb.)—would need to have recording durations of 15 hr. CVRs in smaller aircraft required to have them would be required to have two-hour recording durations. The proposed deadline for installing the longer-duration recorders is January 2019.
From January 2020, CVRs and FDRs must have underwater location devices that broadcast for at least 90 days. EASA’s current regulations do not specify a duration.
In addition, large aircraft delivered from 2005 onward that operate over water would need 8.8-kHz underwater locator devices (ULD) by January 2019. Exempted aircraft include those that don’t fly more than 180 nm. from shore or those equipped with an “automatic means to determine, following an accident,” the impact location with a 6-nm. accuracy, EASA explains.
“An automatic fixed [emergency locator transmitter, or ELT] or an automatic portable ELT are not acceptable if they are not designed to successfully emit in extreme non-survivable accident conditions,” EASA notes. “In addition, an automatic deployable ELT that only relies on water immersion sensors and negative acceleration sensors (‘g’ switches) for detecting impact with water or ground is not acceptable.”
The NPA, which could affect as many as 14,400 European state-registered aircraft and helicopters required to carry either or both types of recorders, also introduces maintenance and inspection requirements designed to ensure in-service recorders—notably the ones being phased out—remain reliable in the interim.
A query of accident and incident reports reveals the problem with older-technology recorders, EASA explains. Looking at some 8,600 reports from the last 10 years, EASA calculates that 24% of magnetic tape CVRs deliver insufficient recording quality, while about 35% of magnetic tape FDRs don’t capture all the data they are designed to record. By comparison, only about 5% of solid-state recorders have similar problems, the regulator says.
The remaining population of so-called obsolete recorders in service is unclear. EASA estimates that about 21% of worldwide aircraft with MTOWs of at least 5,700 kg have magnetic tape CVRs, and 12% have magnetic tape FDRs. The percentages are slightly higher within Europe, at 30% and 20%, respectively, EASA says.