Advances in aircraft technology have contributed significantly to making commercial aviation the safest mode of transportation. Each decade has yielded a significant decrease in the rate of fatal accidents and hull losses despite an increase in air traffic.
The continual evolution of the commercial air transport fleet can be credited with much of this improvement; each successive generation of aircraft has employed new technologies to curb threats to aviation safety. In the future, technology is expected to continue to play a critical role in further enhancing aviation safety.
Airbus and Boeing each forecast explosive growth in future air traffic. Historically, commercial air travel has doubled every 15 years. This significant growth increases the exposure to vulnerabilities in the air transport system.
Despite the recent uptick in accidents, the long-term view has shown that the rate of both fatal accidents and hull losses has steadily decreased over time. To maintain low accident rates that the traveling public demands, the aviation industry must continually evolve and employ new technologies.
A recent Airbus study—“A Statistical Analysis of Commercial Aviation Accidents 1958-2018”—highlighted the three major accident categories (there are 40 total) that have historically caused the most significant number of accidents: controlled flight into terrain (CFIT), loss of control in flight (LOC-I), and runway excursion (RE).
The study further identified each generation of jets and the impact that each had on improving safety. First-generation jets designed in the 1950s were analog aircraft and had crude autoflight systems. The overall accident rate for first-generation aircraft was approximately three accidents per million flights.
Second-generation aircraft from the 1960s and 1970s began to employ more integrated autoflight systems that included more advanced autopilots and autothrottles to ease workload; the accident rate with these aircraft decreased to 0.7 accidents/million flights.
The third generation of jets introduced in the 1980s included more advanced avionics such as glass cockpits (early EFIS) and flight management systems (FMS). The greatest contribution to flight safety was the introduction of GPWS/TAWS (ground proximity warning system/terrain awareness and warning system) that reduced the number of CFIT accidents by 85 percent when compared with second-generation aircraft. The overall accident rate with this generation of aircraft decreased further to 0.2 accidents/million flights.
Fourth-generation jets introduced fly-by-wire technologies with flight envelope protections. Nearly all newly certified air transport and larger business aviation aircraft employ some form of FBW system. As of 2018, approximately half (47 percent) of all air transport jets in service are fourth-generation aircraft. FBW has reduced the number of LOC-I accidents by 75 percent and have cut the overall accident rate in half, to 0.1 accidents/million flights.
Technologies introduced with third- and fourth-generation jets have significantly reduced the rate of both CFIT and LOC-I accidents. Runway excursions are the third major cause of fatal accidents and account for the highest number of hull losses; these events can occur on takeoff or landing.
During landing, runway excursions are being addressed with energy and performance-based technologies. Introduced at the end of the last decade, many of these systems are included on new aircraft or available as upgrades on in-service aircraft. Only 5 percent of in-service air transport aircraft have this technology. Examples of these systems include the Honeywell SmartRunway and SmartLanding system and the Airbus Runway Overrun Prevention System (ROPS).
Honeywell offers its SmartRunway and SmartLanding systems as an upgrade to existing EGPWS Mk V and Mk VII systems. These systems are the next generation of the Honeywell runway awareness and advisory system (RAAS) and are offered by several OEMs. SmartRunway primarily addresses runway incursions, while SmartLanding addresses high-energy runway excursions. SmartLanding alerts pilots if the aircraft is too fast, too high, improperly configured, or going to incur a long landing.
Airbus ROPS was introduced in 2009 on the A380. The system is now available on all Airbus FBW aircraft. ROPS is an alerting system that reduces the exposure to the runway overrun risk, and if necessary, provides active protection. This system provides cues during final approach and the landing rollout; if the runway available is too short for the conditions, ROPS will command a go-around.
During takeoff, a misconfigured aircraft can lead to a runway excursion. Misconfigured takeoffs might involve either the wrong flap setting, no flaps, or the wrong thrust selection. Modern fourth-generation aircraft with highly integrated avionics systems help prevent these situations by comparing FMS performance selections (flaps, thrust, and bleed configuration) with the actual aircraft configuration. As an example, the Airbus A220 will alert the crew (via an electronic CAS message) if the aircraft is not properly configured 60 seconds after engine start. Likewise, the system performs a reasonability check to ensure the proper V-speeds are selected.
It is widely understood that technology is only one part of the solution; improvements in training, procedures, and other “soft safeguards” must also advance. Together, technology, pilots, and operators must continually evolve to meet the expectations to maintain the highest level of safety.
Pilot, safety expert, consultant and aviation journalist - Kipp Lau writes about flight safety and airmanship for AIN. He can be reached at firstname.lastname@example.org