Monitoring flight data helps to improve aviation safety

 - May 7, 2008, 7:47 AM

Knowing what factors contribute to accidents permits operational changes to be made to reduce future risk, according to the UK Civil Aviation Authority, which is encouraging the use of flight-data monitoring (FDM) to make safety-management systems “more effective than traditional means of audit or inspection.” CAA safety regulator James Lyons said, “Repeatable and independent” FDM analysis allows active monitoring and auditing to improve regulatory assurance.

He said Europe’s Joint Aviation Authorities (JAA) and others are making two “significant and complementary” moves to improve knowledge of risk sources: increasing use of voluntary and mandatory non-punitive incident-reporting systems for flight crew and other professional aviators; and extending routine analysis of operational flight-data records.

A challenge for operators is to incorporate flight-data information into safety-management systems, said Lyons. “Used with foresight and imagination, FDM programs are powerful tools for enhancing flight-safety standards.” They can be used to detect adverse trends in behavior and weaknesses in procedures, aircraft design and operations, as well as airport-related issues and in ATC-induced problems.

More Raw Material

The use of quick-access recorders to obtain more comprehensive information than is routinely stored in flight-data recorders provides raw material for analysis of many operational aspects, including pilot technique, handling difficulties, autopilot problems, turbulence, wake-vortex encounters, altitude “busts” and rushed approaches.

Lyons said FDM programs should cover four types of information:

• Event data, defined as exceedance of values that indicate deviation from flight-manual limits, standard operating procedures and “good airmanship” in a single flight.

• Routine measurement from all flights to indicate subtle trends over a wide range of operations that might signal problems related to an airfield, certain types of operation or specific aircraft models.

• Investigation data to follow up incidents subject to mandatory reporting.

• Engineering data, including routine and event information to assist engineering departments, typically extending engine monitoring to other areas such as use of brakes and reverse thrust, autopilot performance and aircraft efficiency.

“Taking action to address identified hazards is the ultimate goal,” said Lyons. “The final stage in the process is to monitor results to check that these have reduced identified risks.”

FDM provides otherwise unavailable information and helps to define actual, rather than theoretical, normal practice. “Current reporting systems have a restricted view of the total operation,” he said, “while a good FDM program gives depth of information to indicate underlying risk patterns.” Viable FDM programs require “normal” operations to be defined and may be sufficient to highlight potential conflicts or, say, a lack of clarity in SOPs, according to Lyons. Such programs should permit analysis to give adequate warning if routine operations demonstrate movements away from acceptable minimums.

Rarely should the confidentiality of FDM ever be broken, except perhaps to ensure specific training for an errant pilot who had not voluntarily reported an incident. Lyons said, “UK experience has rarely shown cases where an important issue has been raised and no report has been submitted. The persons involved have been encouraged through a confidential contact to report. Where no report has been forthcoming, agreed procedures allow remedial action to be taken.”