In 2011, the U.S. National Transportation Safety Board (NTSB) placed the safety of the country’s entire general aviation (GA) sector on its Most Wanted List of Transportation Safety Improvements — and has kept some form of the issue on the list ever since. The NTSB’s actions were triggered by concern about the average of nearly 1,500 GA accidents per year that kill more than 400 pilots and passengers.
The NTSB, which noted that most of these were “repeat accidents” — more precisely, accidents attributed to the same causes that have been assigned to many previous accidents and that occur under similar circumstances — issued 10 safety alerts in 2013, and several more in 2014, that specifically address GA fixed-wing and rotorcraft safety issues.1
The U.S. Federal Aviation Administration (FAA) also is concerned about the disproportionate number of accidents in this sector — 92 percent of all fatal accidents in 2011 were GA accidents, with the majority attributed to pilot error.2 Besides setting a goal of reducing the GA accident rate by 10 percent by 2018, the FAA is working with a variety of stakeholders to change the airman certification standards. The industry-led Aviation Rulemaking Advisory Committee and the Airman Testing Standards and Training Working Group are working with the FAA so that both practical (flight) and knowledge (written) tests will specifically evaluate pilot candidates on their strategies for managing risk.3
With minor variations, the definition of GA in most non-U.S. jurisdictions aligns closely with the one used in the United States: all aviation except military and scheduled commercial passenger/cargo airline flights. Accounting for more than 90 percent of the U.S. civil aircraft fleet, GA primarily involves a significant variety of fixed-wing and rotary-wing aircraft and flight operations, including personal flights in piston-powered single-engine airplanes, on-demand charter flights in piston- or turbine-powered airplanes and corporate travel in medium or heavy twin-engine jets (see “GA Facts”).
Table 1 shows the contrast in accident records for GA versus U.S. Federal Aviation Regulations (FARs) Part 121 scheduled air carrier aircraft in the United States from 2010 through 2012. GA accident rates have remained relatively unchanged for more than a decade — the accident and fatal accident rates averaged 6.77 and 1.28 per 100,000 flight hours, respectively, for the 10 years from 2000 through 2009.4
The GA record is much the same in other countries. Australia reports that private/business operations recorded 15 fatal accidents resulting in 22 fatalities in 2012 — the highest number of fatal accidents in any year in the last 10 years.5 In Canada, there were 242 aircraft accidents in 2013; only nine involved scheduled airline operations.6
|Accidents||Fatal Accidents||Fatalities||Accident Rate per 100,000 Flight Hours||Fatal Accident Rate per 100,000 Flight Hours|
Source: U.S. National Transportation Safety Board
An FAA Fact Sheet lists the five leading causes of fatal U.S. GA accidents between 2001 and 2011:7
- Loss of control–in flight (LOC-I);
- Controlled flight into terrain (CFIT);
- System/component failure–powerplant (SCF-PP);
- Low-altitude operations; and,
Although scheduled airlines face some of these same challenges — LOC-I and CFIT are the two leading causes of fatal accidents for both — the number of GA accidents points to a need to address the issues separately. There also are threats that are unique to either GA or to commercial jets. For example, GA operations are more prone to low-altitude and fuel-related threats, while commercial jet aircraft are more likely to be involved in runway excursions.8
Top Safety Alerts
Because LOC-I is the most common type of fatal GA accident, NTSB Safety Alert (SA) 019, Prevent Aerodynamic Stalls at Low Altitude, addresses a major cause of LOC-I accidents. According to the safety alert, pilots involved in these accidents typically have failed to avoid the conditions leading to an aerodynamic stall, to recognize the symptoms of an approaching stall and to use proper stall-recovery procedures.
The safety alert also reveals that these types of accidents arise from a variety of circumstances that tend to repeat themselves in GA flight operations — becoming distracted while maneuvering in the airport traffic pattern, fixating on ground objects and coping with emergencies.
Another safety alert, Reduced Visual References Require Vigilance, NTSB SA-020, underscores that threat, which has contributed to fatal accidents in airlines and the military and is particularly problematic among GA flights, many of which are conducted under visual flight rules (VFR). Outside visual references (e.g., horizon, terrain) needed to safely fly under VFR are diminished when visibility is near or below visual meteorological conditions and during dark-night conditions (overcast and/or moonless nights).
The NTSB says that accidents involving reduced visual references generally result from the same causes as GA’s two biggest killers — LOC-I and CFIT. SA-020 highlights the typical scenarios: VFR pilots fly into instrument meteorological conditions (IMC) and either collide with nearby terrain or lose control of their aircraft due to spatial disorientation; instrument-rated pilots experience spatial disorientation while flying in IMC; and pilots lose control of their aircraft as a result of spatial disorientation or are involved in a CFIT accident as a result of a visual illusion while attempting to rely on inadequate outside visual references during dark-night conditions.
SCF-PP is the third most common type of fatal GA accident. The GA sector relies heavily on the use of single-engine piston-powered airplanes, which account for more than 80 percent of the U.S. GA fleet.9 These airplanes generally are certificated to less stringent standards than large turbine-powered passenger-carrying transport aircraft. The fastest-growing segment of the GA fleet — experimental-amateur built (E-AB) aircraft (often called “home-builts”) — is responsible for a disproportionate share of accidents (4 percent of flight hours, 21 percent of fatal accidents), in part because “most E-ABs are simple aircraft that may incorporate previously untested systems and modified airframes and instruments,” the U.S. Government Accountability Office (GAO) said in a 2012 report.10
NTSB SA-021, “Is Your Aircraft Talking to You? Listen!” says that the circumstances involved in fatal accidents involving system or component failures are “remarkably similar to those of previous accidents” and that “pilots are not taking advantage of the lessons learned from such tragedies that could help them avoid making the same mistakes.”11 Too often, pilots attempt a flight even though they are aware that something is not quite right mechanically with their aircraft.
Because errors committed by maintenance personnel contribute to many of the aircraft system and/or component failures identified in accident investigations, and because the improper actions of pilots sometimes exacerbate these failures and contribute to LOC-I due to aerodynamic stalls and to LOC-I and CFIT during flight with reduced visual references, the NTSB’s fourth and fifth safety alerts exhort mechanics (Mechanics: Manage Risks to Ensure Safety, SA-022) and pilots (Pilots: Manage Risks to Ensure Safety, SA-023) to practice risk-management strategies while fixing or flying aircraft.
For GA pilots, the NTSB suggests a variety of risk-management strategies to counter the human factors that can contribute to these types of accidents. Most of these strategies involve aspects of pilot performance. For example, the NTSB says pilots should:
- Assess skill proficiency levels and the unsafe impact of any medical condition or medication on performance before attempting a flight;
- Recognize the adverse effects of fatigue — including forgetfulness, poor decision making and reduced vigilance — and strive to eliminate or reduce contributors to fatigue;
- Develop effective strategies to cope with stress and recognize the harmful effects certain attitudes have on the safety of flight; and,
- Refuse to succumb to external pressures to complete a flight in conditions that they are not comfortable with.
Learning From Airlines
Because scheduled commercial air carriers boast the lowest aircraft accident rates, carrying millions of passengers safely to their destinations each year, the GA sector should consider emulating some of what they do to improve the GA safety record. It is true the airlines possess risk-management advantages that much of GA does not enjoy. For example, airlines typically operate multiengine turbine-powered airplanes, piloted by at least two crewmembers with high levels of training and experience. As part of their safety management systems, the airlines also use a variety of organizational tools such as line operations safety audits (LOSA observations of crews) and flight operational quality assurance (the analysis of data from routine flight operations) to help achieve a high level of safety.
In the United States, general aviation (GA) includes all aviation except military operations and scheduled commercial passenger and cargo airline flights.1,2
In 2010, there were 223,000 GA aircraft in the United States (more than 360,000 worldwide) flying more than 23 million hours (more than 35 million hours worldwide), transporting 166 million passengers per year.
GA includes piston- and turbine-powered (single- and multi-engine) airplanes and rotorcraft; balloons; airships; and gliders.
GA flight activities include personal/recreational, instructional, business and corporate transport, on-demand charter (air taxi), air ambulance, sight-seeing; and a variety of types of aerial observation/application work (mapping, patrol, surveillance, search-and-rescue, crop production, fire suppression, etc.).
Two-thirds of U.S. GA flight hours are conducted for business purposes.
GA employs almost 1.3 million people and accounts for 1 percent of annual gross domestic product, contributing $150 billion to the U.S. economy and more than $53 billion in wages.
— DW, GB
- General Aviation Manufacturers Association (GAMA). What is GA?
- GAMA. General Aviation’s Contribution to the U.S. Economy. 2005. Link is to the 2006 edition.
However, even though they use some of the most sophisticated aircraft in civil aviation, along with the industry’s most experienced and best-trained flight crews, the airlines recognize that pilots still make mistakes — they get distracted and forget important items, they perform the wrong actions or they perform the correct actions too late. To compensate for these limitations, airline flight crews operate within many layers of defenses, including training in best-practice behaviors designed to cover a “multitude of sins.”
Therefore, even though most GA flight operations lack some of the safety infrastructure of the airlines, GA pilots can still benefit from adopting — and adapting to their particular flight operations — the risk-reduction strategies used by airline flight crews to overcome the human limitations that are common to all pilots. Some of these include:
- Standard operating procedures (SOPs) — These are standardized ways of accomplishing tasks necessary to ensure safe operations for every phase of flight. SOP compliance is essential in coordinating the actions of airline flight crews, but these procedures also incorporate the collective wisdom of lessons learned from a multitude of aircraft accidents. Those involved in single-pilot GA operations who do not already use SOPs should consult with the regulatory authority or a flight training provider for help developing SOPs applicable to the aircraft they fly.
- Flows and checklists — First officers and captains conduct standard flows for normal, abnormal and emergency operations. These memorized procedures streamline operations and help pilots properly configure the aircraft for the different phases of flight. GA pilots often rely on mnemonics (memory aids based on acronyms) and other strategies that are analogous to flows. Observing strict checklist discipline is an effective countermeasure against forgetfulness; checklists help verify that flow items and other critical actions are completed correctly.
- Verbalized procedures — Airline SOPs require crews to conduct verbal departure and approach briefings and to make and acknowledge callouts for critical parameters (e.g., speeds, altitudes, flight path deviations). Verbalizing contributes to effective monitoring of the flight path and of aircraft instruments and systems — a skill that is essential for safe flight operations but often inadequately conducted by pilots — by providing a redundancy that helps pilots to better focus on the task at hand and immediately recognize deviations.
- Distraction management — Airline pilots manage distractions primarily by complying with the sterile flight deck rule (outlined in FARs Part 121.542 and Part 135.100), which prohibits crewmembers from engaging in nonessential activities during critical phases of flight. The exact nature of a “critical phase” of flight might differ between scheduled airline operations and GA, but the principle is still relevant. Though the sterile flight deck rule is not required for most Part 91 operations, GA pilots should avoid extraneous conversations and all nonessential activities that might cause distraction during taxi, takeoff, approach, landing and any flight in the vicinity of an airport. Pilots also should brief their passengers to avoid conversations with them during these high-risk phases of flight.
- Automation management — With the recent introduction of sophisticated avionics and automated systems into small aircraft cockpits, GA pilots, like their airline counterparts before them, are learning to adapt to the challenges these systems present. A recent NTSB study found that light single-engine airplanes equipped with glass cockpits had a higher fatal accident rate and were involved in almost twice as many fatal accidents as comparable airplanes with so-called steam gauges (analog instruments).12 GA pilots must understand not only how these systems work but also the complications they can present — including such problems as mode confusion, automation complacency and the diminution of hand-flying skills (automation dependency).
- Crew resource management — Airline flight crews practice crew resource management (CRM) skills such as using effective decision-making strategies, managing stress, working together as a team and communicating assertively. Single-pilot resource management (SRM) borrows from airline CRM doctrine by teaching GA pilots to likewise manage all available resources — from inside the cockpit and outside the aircraft — to achieve safe flight. The emphasis for single pilots, however, is less on team skills and more on other aspects of CRM, such as aeronautical decision making, risk management, task management, situational awareness and automation management.13
- Threat and error management — Used primarily as an evaluation tool for LOSA, threat and error management (TEM) is increasingly being used by airline flight crews as a framework to manage risks. TEM assumes that threats to safe flight are always present and, despite their best efforts to avoid them, errors made by pilots sometimes occur. GA pilots can use the TEM framework to assist them in identifying threats that originate from sources identified in the familiar FAA PAVE model: the physiological or psychological condition of the Pilot, the Aircraft, the enVironment and External pressures. This framework also can be used to help GA pilots employ effective countermeasures to avoid, capture and correct for errors that could jeopardize safety.14
Other airline-generated flight safety practices also could transfer to the GA environment. For example, the Air Charter Safety Foundation is implementing an FAA-sanctioned aviation safety action program (ASAP) that allows employees of participating Part 135 charter operators to report personnel errors and other safety issues to management without fear of regulatory enforcement action from the FAA or punitive consequences from the company — with a few specific exemptions for behavior outside the bounds of inadvertent error. Others are looking into the possibility of expanding this into some Part 91 operations.15
Efforts by the NTSB, the FAA and other organizations are converging to develop strategies to improve GA safety. This sector should look closely at the airline industry for effective models and assistance in adapting them. The airlines have achieved unprecedented levels of safety, in part because their systems have evolved (and continue to evolve) to include a set of proven best-practice countermeasures that flight crews use to effectively manage risk on the flight deck. Similar improvements in GA safety could be achieved if pilots and operators were to take a page from their playbook.
Professor Dale Wilson teaches courses in flight crew human factors and risk management at Central Washington University in Ellensburg, Washington, U.S. Gerald Binnema, formerly an air accident investigator with the Transportation Safety Board of Canada, is an aviation safety consultant based in British Columbia, Canada. The authors’ recent book, Managing Risk: Best Practices for Pilots, describes significant threats to safe flight operations, offers insights into how and why pilots make errors that exacerbate those threats and provides countermeasures to effectively manage them.
- NTSB. Safety Alerts.
- GAO. General Aviation Safety: Additional FAA Efforts Could Help Identify and Mitigate Safety Risks. 2012.
- Parson, Susan. “Airman Testing Reform Update,” FAA Safety Briefing, 52.6 (November/December 2013): 15–16.
- NTSB. Accidents, Fatalities, and Rates, 1993 through 2012, U.S. General Aviation (Tables 6, 10).
- Australian Transport Safety Bureau. Aviation Occurrence Statistics, 2003 to 2012.
- Transportation Safety Board of Canada. Statistical Summary — Aviation Occurrences 2013.
- FAA. Fact Sheet — General Aviation Safety (January 2014). Link is to 2016 version.
- Boeing. Statistical Summary of Commercial Jet Airplane Accidents: Worldwide Operations, 1959–2013. Seattle: Boeing. August 2014.
- General Aviation Manufacturers Association. General Aviation’s Contribution to the U.S. Economy. 2005. Link is to the 2006 edition.
- GAO. General Aviation Safety: Additional FAA Efforts Could Help Identify and Mitigate Safety Risks. 2012: 12.
- NTSB. Safety Alert “Is Your Aircraft Talking to You? Listen!” (SA-021). March 2013.
- NTSB. Introduction of Glass Cockpit Avionics into Light Aircraft, Safety Study (NTSB/SS-10/01). 2010.
- FAA. Pilot’s Handbook of Aeronautical Knowledge, Chapter 17, Aeronautical Decision-Making (FAA-H-8083-25A). 2008.
- Wilson, Dale; Underhill, Jason. “Managing Risk: A Threat & Error Management Approach,” NAFI Mentor, 16.2 (March/April 2014): 20–24.
- Thurber, Matt. “Air Charter Safety Foundation ASAP Expands To West Coast,” AIN Online. May 2014.
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