FAA Safety Official Reflects on Airline Safety and Role of Technology

During a recent speech to the International Society of Air Safety Investigators, the FAA's top safety official, Nicholas A. Sabatini, reflected on the extraordinary safety record of modern aviation and the contributions of technology in that quest.

Mr. Sabatini told his audience that he is frequently asked, "What are the major causes of fatal airliner accidents?" and he answers by saying that in the U.S. and the rest of the developed world, fatal airline accidents are such rare events these days that "common causes" no longer exist.

Air travel is so safe that we at FAA find it a challenge to meaningfully express the level of safety, Mr. Sabatini said.  Expressed as the number of fatal accidents per 100,000 departures, the rate is now at .022, but that number consists largely of cargo accidents or cases where a ground employee is struck by an aircraft on the ramp or an employee drives a tug into an aircraft.

So in several respects the number is even less:  The rate for fatal airline accidents for passenger airlines is about 0.007 per 100,000 departures; and if only passenger jet fatal accidents are considered, the number is about half that level.  At that rate, one must fly every day for 43,000 years to get to an even chance of being killed in an airline accident. This means one is about 40 times safer in an airliner than on a U.S. Interstate highway, which is considered the country's safest.

"Pilots are safer on the job than when they are not at work." Mr. Sabatini quipped.

Role of Technology

Mr. Sabatini pointed out that, for the most part, it's been continual improvements in technology that have produced this achievement.  Here are some of his examples:

• Pressurized aircraft in the 1940s started flying above most of the weather and terrain, at least en route.  That change alone significantly reduced CFIT (controlled flight into terrain) accidents and loss of control in flight.

• The introduction of VORs (VHF omnidirectional ranges) and the first instrument landing systems in the 1940s and 1950s also drove down the number of CFIT accidents and approach-and-landing accidents.  VOR/DME (distance measuring equipment) receivers in the 1960s further reduced those types of events.

• Radar in the 1950s substantially improved our ability to know the whereabouts of aircraft and convective weather.

• The introduction of the jet engine dramatically increased engine reliability, for about a 20-fold increase.  Within several years of the first jet in the U.S. fleet, reliability increased 50-fold.  Now we are approaching 100-fold versus the pinnacle of reciprocating engine technology.  Before the jet, we averaged 3.5 fatal air carrier accidents per year due to engine failure in a rather small system.  In contrast, Part 121 jet operators have had just two such fatal accidents in the past 20 years (Sioux City and Pensacola).

• With TCAS (traffic collision avoidance systems), no Part 121 U.S. carrier has had a midair collision since 1978.  Previously, fatal mid-airs had been common.

• Between 1946 and 1955, large passenger aircraft averaged 3.5 fatal CFIT accidents a year, and through the mid-70s there were still two fatal passenger airline accidents per year on average due to CFIT.  In contrast, no jet operator has suffered such an event in U.S. airspace since 1974.

• With the six-axis simulator, using real data from real flights, we have improved crew resource management training with real-world scenarios.

Mr. Sabatini disagrees with the view that with accident rates at such a low level, we should no longer expect substantial breakthroughs in future rates.  Rather, he believes we are on the threshold of reaching the next level in commercial aviation safety, and information is the key to the next series of breakthroughs.

We are probably using only about five percent of the safety information that resides with operators, manufacturers, repair stations, suppliers, and others in the aviation community, Mr. Sabatini says, all of which could provide useful information about trends, and precursors, about what is going on every day in  manufacturing, maintenance and operations.

Up to now, safety improvements have come largely from forensics and diagnostics after an accident.  Sabatini wants to move on to a more prognostic or predictive approach, but we need more data points.  And we need analytical expertise to discern trends and identify precursors, and we need to share what we learn, Sabatini said.

He reminded his audience that we're already gathering information to help identify trends and precursors with initiatives such as ASAP (aviation safety action program) and FOQA (flight operational quality assurance).  ASAP encourages airline employees to voluntarily report critical safety information and FOQA collects and analyzes digital flight data generated during normal operations.

Mr. Sabatini also acknowledged the work of CAST (commercial aviation safety team), which includes representatives from government, industry, and employee groups, to develop an integrated data-driven safety strategy, and the new FAA Aviation Safety Analytical Unit that is working with NASA on ASIAS (aviation safety information analysis and sharing) systems, which are consolidating and leveraging data from several sources with advanced data analytical tools.  05-17-2006.

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