NTSB Wants Fixes To Airbus Cockpit Electronics

49 Reported Cases Of Dark Displays In Recent Years

Few would argue that so-called "glass cockpits" are a major leap forward in cockpit management and crew safety... until those panels go dark in-flight, which the National Transportation Safety Board says has happened at least 49 times in recent years onboard several Airbus airliners.

On Wednesday, the NTSB issued five recommendations to address concerns about cockpit displays going inop on Airbus A319 and A320 narrow bodies. Of the 49 incidents reported to the Board, seven involved all six cockpit displays going blank at once... something safety experts once thought was all-but impossible.

Sixteen planes lost five of the six cockpit displays. In addition to flight instruments and engine monitoring systems, loss of the avionics displays also resulted in the loss of comm systems, transponders, and traffic advisory systems.

In January of this year, a United A320 had to make a hasty return to Newark Liberty, when the captain's primary flight display (PFD) and navigational display (ND), along with the upper electronic centralized aircraft monitoring (ECAM) display, went blank on takeoff. The plane was able to make a safe emergency landing, helped greatly by the fact conditions were VMC.

The NTSB notes the first officer's ND remained functional, as did the lower ECAM display. The first officer also reported that the attitude information on his PFD was initially not usable, but that the information appeared to be reliable later in the flight.

Those circumstances were similar to those experienced onboard a British Airways A319 three years before, which suffered failures to five of six cockpit displays while cruising at FL200 from London to Budapest. Most of the screens returned within 90 seconds.

British investigators have already issued safety recommendations related to the problem, and Airbus issued a safety bulletin in May 2007 recommending new wiring fixes and increased crew training on how to handle electrical systems failures. But those fixes aren't mandatory, and the NTSB says they should be.

Included in the six recommendations from the NTSB are calls for a backup power supply to be added to the standby attitude indicator, and the automatic reconfiguration of the AC essential bus power supply in the event that the AC 1 electrical bus fails. The NTSB also wants greater crew training, and additional simulator time for pilots to learn how to handle such failures.

aero-news.net

Fonte: Flight Safety Information 25/07/2008.