The predominate causes of general aviation accidents aren’t a mystery. Each month in these pages, each year in the AOPA Aviation Safety Institute’s Nall Report and every day at the NTSB, mishaps are reviewed, dissected, catalogued and judged. The depressing thing about this process is the mind-numbing predictability of it all: Over time, some specific proportion of general aviation accidents will be caused by one thing while other causes will have their own percentage. The numbers don’t change that much from month to month, or year to year. It’s frustrating.
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“Because we investigate each of the 1500 GA accidents that occur in the United States every year, we see the same types of accidents over and over again,” NTSB Chairman Deborah A.P. Hersman agreed in a press release. “What’s especially tragic is that so many of these accidents are entirely preventable.”
Ultimately, preventing accidents is what the NTSB is all about, so it’s reasonable to presume its frustration level is rising, also, perhaps since there are relatively few accidents involving corporate, air taxi and air carrier aircraft. It’s entirely possible, then, that the NTSB is a mite frustrated with general aviation, and that’s what’s behind what in our memory is a relatively unusual step: It simultaneously issued five “Safety Alerts” focused on general aviation operations.
The NTSB Safety Alert is a “brief information sheet that pinpoints a particular safety hazard and offers practical remedies to address the issue.” Three of the alerts focus on topics related to some of the most common defining events for fatal GA accidents: low-altitude stalls, spatial disorientation and controlled flight into terrain, plus mechanical problems. The other two seek to mitigate risks faced both by pilots and mechanics. Let’s explore each of them
Low-Altitude Stalls
The NTSB tell us that, “While maneuvering an airplane at low altitude in visual meteorological conditions (VMC), many pilots fail to:
• Avoid conditions that lead to an aerodynamic stall,
• Recognize the warning signs of a stall onset, and
• Apply appropriate recovery techniques.”
Many stall accidents occurring in visual conditions result when a pilot is momentarily distracted from the primary task of flying, such as while maneuvering in the airport traffic pattern, during an emergency, or when fixating on ground objects. The NTSB also tells us that, “Aerodynamic stall accidents fall into the ‘loss of control in flight’ category, which is the most common defining event for fatal accidents in the personal flying sector of general aviation.”
What can be done to prevent these kinds of accidents? The sidebar above summarizes the NTSB’s recommendations but, in our view, most of these accidents can be prevented by avoiding low-altitude maneuvering, except when landing or taking off. Yes, many missions such as pipeline or transmission line patrol, wildlife spotting and the like require low-level flight. But, too often, a low-altitude stall is the predictable result of showing off.
High-speed, low-level flying, incorporating steep turns, especially at the top of what might be considered “zoom climbs,” is an excellent recipe for a low-altitude stall. This type of maneuvering is what we mean by “showing off.” Based on the NTSB’s too-long history of investigating this type of accident, here’s what it has to say about them: “Resist the temptation to perform maneuvers in an effort to impress people, including passengers, other pilots, persons on the ground, or others via an onboard camera. ‘Showing off’ can be a deadly distraction because it diverts your attention away from the primary task of safe flying.”
Reduced Visibility
When pilots think of reduced flight visibility, we often think of IFR, or at least marginal VFR. The classic reduced-visibility accident, of course, is the VFR-into-IMC mishap, where a VFR-only pilot encounters instrument conditions and doesn’t have the training or equipment to safely extricate himself before succumbing to spatial disorientation.
But flight in low-visibility conditions isn’t restricted to weather phenomena; it can occur in many other situations. Perhaps chief among them is night flying, but dusk/dawn conditions, overcasts, low-angle sunlight near the earth’s poles, as well as man-made situations like smoke from a large fire, all can result in the same dangerous visibility restrictions to flight.
“Historically, about two-thirds of all general aviation accidents that occur in reduced-visibility weather conditions are fatal,” the NTSB’s Safety Alert states. “These accidents typically involve pilot spatial disorientation or controlled flight into terrain. Even in visual weather conditions, flights at night over areas with limited ground lighting (which provides few visual ground references) can be challenging.”
It’s perhaps an oversimplification to lump VFR-into-IMC accidents into the same category as controlled flight into terrain (CFIT) and night-visibility accidents. The only commonality between them is the lack of visibility, and we’d argue that the classic, traditional accident sequences for each differ substantially. But, that’s what the Board chose to do, so let’s dissect its recommendations.
First and foremost? “Obtain an official preflight weather briefing,” says the NTSB, “and use all appropriate sources of weather information to make timely in-flight decisions.” In fact, weather-related accidents are unusually lethal, according to the Nall Report. “[A]ttempts to fly by visual references in instrument conditions accounted for the lion’s share of fatalities,” in 2010, it said. Of the 29 VFR-into-IMC accidents identified, 21 were fatal, for a lethality rate greater than 72 percent.
When it comes to CFIT, it should be obvious that better awareness of surrounding terrain, usually resulting from preflight planning, goes a long way toward preventing this type of accident. Most CFIT accidents occur at night, and the NTSB notes, “Remote areas with limited ground lighting provide limited visual references cues for pilots, which can be disorienting or render rising terrain visually imperceptible. When planning a night VFR flight, use topographic references to familiarize yourself with surrounding terrain.”
One way pilots can help prevent CFIT accidents at night is to adopt some of the procedures and standards associated with IFR flight. For example, obtain and use IFR charts to ensure terrain clearance at night. Follow airways, and adhere to their minimum altitudes, then plan on using published instrument procedures, especially at remote airports in mountainous terrain. Says the NTSB, “Consider following instrument procedures if you are instrument rated or avoiding areas with limited ground lighting (such as remote or mountainous areas) if you are not.”
A final note on operations in low-visibility and at night: Don’t overlook the “tricks” such conditions can play on human physiology, which result in well-known visual and sensory illusions. Spatial disorientation is perhaps the best-known of these. A very valuable discussion of them and how they can impact safe flight operations is in the FAA’s Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25A.
Aircraft Condition
“Documented mechanical failures or errors in aircraft maintenance caused 15 percent of all non-commercial fixed-wing accidents in 2010,” stated the Nall Report, “including 10 percent of fatal accidents.” The NTSB wants pilots to know their aircraft often is signalling potential problems if the symptoms aren’t recognized and remedied.
Even though most of the technology and mechanisms aboard personal aircraft are relatively uncomplicated—at least when compared to a modern automobile or jet transport—they still require skilled care and feeding. We, along with the NTSB, will get to a mechanic’s role in accident prevention in the next section, but we all need to understand and consider the pilot’s role in ensuring the aircraft is mechanically ready for safe flight. Sadly, even when we know there might be an issue, pilots elect to fly the airplane anyway, perhaps on a test flight. The accident record shows departing with a known mechanical problem doesn’t bode well for successful completion of a flight.
That pool of oil or hydraulic fluid found under the airplane during your pre-flight inspection? Where’s it coming from? How long has it been leaking? What system is it from? What about that clunking sound when a control surface is exercised throughout its full range of motion? How secure is that cowling? Is that looseness in the elevator something new, or has it been that way for a while? What’s your airplane’s normal oil pressure and oil temperature?
All these considerations, and more, go into a pilot’s determination an aircraft is safe for flight. The NTSB wants pilots to remember that and more. “Resist the temptation to let external pressures, such as the desire to save time or money, influence you to fly an aircraft that shows signs of a potential problem,” it said in an alert. Stating what we consider to be the obvious, “Safety should take precedence over all other considerations.” But how? “Listen to what your aircraft is telling you, and remember that shortcuts on the ground can cost you dearly in flight.” In other words, it’s better to be on the ground, wishing you were in the air, than to be in the air, wishing you were on the ground.
Mechanic Mistakes
Most of the time, responsibility for safe operations is thought to be solely the province of the pilot. Instead, it’s a responsibility shared among pilots and mechanics. Aircraft owners know how hard it can be to find a mechanic or shop we trust to perform maintenance and repairs correctly, on time and within our budget. Indeed, it’s often said an aircraft owner can easily obtain two of those three objectives, but never all three.
But the NTSB’s issue isn’t with the cost of maintenance. Rather, it’s important for all concerned to acknowledge mechanics can make mistakes, and those mistakes usually don’t happen in a vacuum. For example, the NTSB encourages us to “understand the safety hazards associated with human fatigue,” noting it “has been linked to forgetfulness, poor decision making, reduced vigilance, and other factors.” In other words, mechanics get tired and forget things, too.
When working on an aircraft, mechanics need to pay “particular attention to the safety and security of the items that undergo maintenance and any surrounding components that may have been disconnected or loosened (possibly to ease access). Pilots can help, too, by ensuring cowlings, inspection covers and fairings are secure, checking all aircraft systems during pre-flight inspections and the before-takeoff run up. Having correct and current data when performing maintenance is something the FAA stresses and the NTSB echoes. “Carefully follow manufacturers’ instructions to ensure that the work is completed as specified. Always refer to up-to-date instructions and manuals when performing a task, and ask questions of another qualified person if something is unfamiliar to you.”
Finally, the return-to-service inspection can be a critical item. When one mechanic is doing the work, another one should be doing such an inspection: “Inspect the safety and security of critical items that have received maintenance.” One problem throughout GA, however, is the single mechanic doing the work and the inspection, perhaps with unskilled assistance.
Make Better Decisions
At the end of the day, many GA accidents could be eliminated if pilots simply made better decisions. The NTSB puts it thusly: “Although few pilots knowingly accept severe risks, accidents can also result when several risks of marginal severity are not identified or are ineffectively managed by the pilot and compound into a dangerous situation. Accidents also result when the pilot does not accurately perceive situations that involve high levels of risk.” The punchline? “Ineffective risk management or poor aeronautical decision-making can be associated with almost any type of fatal accident across all general aviation sectors,” sayeth the NTSB.
In other words, we fail to understand the cumulative consequences of our actions. Trying to beat weather while stretching fuel and dealing with a reluctant transfer pump. Finding ourselves VFR-only on top of a solid cloud deck, with dwindling fuel, daylight or options. Launching an overweight airplane into known or likely icing conditions with an inoperative TKS system. Failing to replace the ship’s battery in response to hard starting and dim night lighting. Needing to shoot an approach to minimums at the end of a long day filled with meetings so we can attend tomorrow’s, despite how tired we feel. And while multiple decisions certainly can affect a flight’s outcome, “a cornerstone of risk management is minimizing vulnerability to single-point failures,” offers the Nall Report.
Putting It All Together
“Sadly, the circumstances of each new accident are often remarkably similar to those of previous accidents,” the NTSB stated in one of its Safety Alerts. That’s the whole point behind them, as well as the major source of frustration that seeps through the Board’s efforts and, truth be told, this article.
At some point, technology may take care of things like night or low-viz CFIT, spatial disorientation resulting from VFR-into-IMC, low-altitude stalls and the like. It likely won’t help—and could exacerbate—mechanical problems, which will continue as long as humans work on and fly aircraft. Until then, we all must understand that flying personal aircraft can be risky if we don’t take the appropriate steps to eliminate or minimize challenges like bad weather and the urge to show off, pay better attention to mechanical issues and think a little about what we’re about to do before takeoff.
0613-AVOIDING-LOW-ALTITUDE.pdf
0613-FLIGHT-REDUCED-VISABILITY.pdf
