Category Archives: Aviation Safety

Inside the NTSB’s General Aviation Investigative Process

Do We See and Avoid or Avoid Seeing?

 By John O’Callaghan

This is the fourth blog in a new series of posts about the NTSB’s general aviation investigative process. This series, written by NTSB staff, explores how medical, mechanical, and general safety issues are examined in our investigations.

John O’Callaghan at a runway friction test in Conroe, TX.

As a National Resource Specialist for Aircraft Performance, which is government-speak for a technical expert in the aerodynamics and flight mechanics of aircraft, I work to determine and analyze the motion of aircraft and the physical forces that produce that motion. In particular, following an accident or incident, I attempt to define an aircraft’s position and orientation during the relevant portion of the flight, and determine its response to control inputs, external disturbances, ground forces, and other factors that could affect its trajectory.

I recently reviewed a 2009 cockpit video taken while I was testing a video recording device in a Bellanca Citabria. The footage called to mind recent NTSB cases that highlight the fallacies inherent in one of aviation’s oldest mantras—“see and avoid.”

The video from the camera mounted over my left shoulder reveals a hazy blue sky above and the Potomac River winding lazily below the Citabria’s plexiglass windows. It shows my head dutifully swiveling as I scan the practice area for traffic in preparation for a series of aerobatic maneuvers intended to test a prototype “portable flight data recorder” developed by a friend of mine. I’m flying in the Washington, DC, Special Flight Rules Area so I’m in contact with Potomac Approach, which helpfully keeps a radar’s eye on me and nearby traffic and conveys what I fail to see.

“Citabria 758, traffic about a mile southwest of your position. A Cherokee is in the practice area, altitude indicates . . . I’m not showing an altitude right now.”

On the video, my head moves around a little more as I respond, “758 looking, thank you.”

The controller then alerts the Cherokee. “Cherokee [call sign], traffic seems to be about 1-mile orbiting, altitude indicates 3,600, a Citabria.”

I’m still looking with no success when Potomac advises that the Cherokee is at 2,200 ft. The controller lets me and the Cherokee pilot know that we are getting close to each other.

 “Cherokee [callsign], traffic just southeast of you, about less than 1 mile, Citabria in the practice area, altitude indicates 3,700.”

 “Roger, we’ll keep our eyes open for that Citabria in the practice area.”

“Citabria 758, that traffic is just northwest of you, less than a mile now, and his altitude still indicates 2,300, appears to be eastbound.”

“758 still looking, thank you.”

The video now shows me craning my neck left and right, leaning forward, scanning the entire symmetrical view offered by an airplane with its seats on the centerline. The airplane banks left and right in gentle turns as I maneuver, trying in vain to spot the Cherokee. A little over 3 minutes after Potomac’s initial advisory, I give up.

“Potomac, Citabria 758 still looking for that traffic . . . is he still a factor?”

“758, now he’s about 5 miles north of you, no factor.”

I don’t know if the Cherokee pilot ever saw me, but if he did, he didn’t announce it. I imagine that most general aviation pilots don’t need to accumulate too many hours before they have an experience much like mine, or its more unnerving inverse: suddenly seeing an airplane that you had no clue about whiz by close enough to read the N-number. Both situations point to the inherent limitations of the “see-and-avoid” concept: the foundation of collision avoidance in visual meteorological conditions (VMC) under visual flight rules (VFR).

My flight was a personal one, unrelated to my duties as an aircraft performance engineer at the NTSB. However, my fruitless search for the Cherokee was consistent with conclusions the NTSB has drawn from investigating a number of midair collisions, and which call to mind what can happen when traffic remains unnoticed.

As detailed in the NTSB reports concerning two midair collisions that occurred in 2015, described further below, the see-and-avoid concept relies on a pilot to look through the cockpit windows, identify other aircraft, decide if any aircraft are collision threats, and, if necessary, take the appropriate action to avert a collision. There are inherent limitations of this concept, including limitations of the human visual and information processing systems, pilot tasks that compete with the requirement to scan for traffic, the limited field of view from the cockpit, and environmental factors that could diminish the visibility of other aircraft.

In a collision between an F-16 and a Cessna 150 near Moncks Corner, South Carolina, in July 2015, the F-16 pilot was unable to spot the C150, even though the Charleston Approach controller had alerted him to the presence of the airplane. The F-16, call sign “Death41,” was flying under instrument flight rules and communicating with air traffic control (ATC); the C150 was flying under VFR and not communicating with ATC.

“Death41, traffic 12 o’clock 2 miles opposite direction 1200 indicated type unknown.”

“Death41 looking.”

“41 turn left heading 180 if you don’t have that traffic in sight.”

“Confirm 2 miles?”

“Death41, if you don’t have that traffic in sight turn left heading 180 immediately.”

[unintelligible reply]

Even before the controller finished her last instruction, the F-16 had begun a standard-rate turn to the left. The F-16 was heavy and, at 240 knots, moving relatively slowly—for a fighter jet. Contrary to what one might think, it could not turn much faster in those conditions. Twenty-three seconds after the controller’s last instruction, the F-16 and the C150 collided at about 1,470 ft above the Cooper River. The crippled F-16 flew for another 2.5 minutes before the pilot ejected safely, and the jet subsequently crashed. The C150 crashed almost directly beneath the collision site, and both the pilot and his passenger died.

We determined the probable cause of this accident was the approach controller’s failure to provide an appropriate resolution to the conflict between the F-16 and the Cessna. Contributing to the accident were the inherent limitations of the see-and-avoid concept, resulting in both pilots’ inability to take evasive action in time to avert the collision.

Midair collisions can happen even when both aircraft are in communication with ATC. A month after the Moncks Corner midair collision, a North American Rockwell Sabreliner collided with a Cessna 172 in the busy traffic pattern at Brown Field in San Diego. Both aircraft were under Brown Tower’s control and on a right downwind for runway 26R, with the Sabreliner outside of and overtaking the C172. The tower controller intended to instruct the C172 to perform a right, 360-degree turn to position him behind the Sabreliner; however, he mistakenly instructed a different C172 to perform the maneuver, and immediately after instructed the Sabreliner to turn right base.

The Sabreliner and C172 subsequently collided, and all five people on the two aircraft died. The cockpit voice recorder on the Sabreliner indicated that both Sabreliner pilots were aware of and concerned about the busy traffic pattern, pointing out other aircraft to each other. One of the nonflying crew in the back of the plane is even heard asking, “see him right there?” presumably referring to traffic. Yet the collision still occurred.

We determined the probable cause of the accident was the local controller’s failure to properly identify the aircraft in the pattern and to ensure control instructions provided to the intended Cessna on downwind were being performed before turning [the Sabreliner] into its path for landing. Contributing to the accident were the inherent limitations of the see-and-avoid concept, resulting in the inability of the pilots involved to take evasive action in time to avert the collision.

My role in the investigations of the Moncks Corner and San Diego collisions was to reconstruct the motion of the airplanes based on radar data and other information, and to evaluate the resulting visibility of each aircraft from the cockpit of the other. In addition, it was my job to evaluate how new collision avoidance technology—such as cockpit displays that provide a radar‑like view of surrounding traffic based on automatic dependent surveillance-broadcast (ADS-B) information—could have averted each accident.

One objective of these visibility studies was to determine whether either of the airplanes involved in the collision were obstructed from the other pilot’s field of view by cockpit structures, or whether the pilots had an unobstructed view of each other but simply failed to see one another (because seeing other traffic from the cockpit is hard!). To find out, we measured the geometries of the window and other structures of exemplar airplanes with laser-scanning equipment, and the resulting measurements were used to determine where the windows were in each pilot’s field of view and whether the other airplane appeared within the windows or not. The results were most intuitively presented by creating computer animations of the collision from the point of view of each pilot using flight simulation software (Microsoft Flight Simulator X) to create the outside scenery and airplane models.

Readers can watch the animations we created for the Moncks Corner and San Diego collisions on our YouTube channel and judge the visibility results for themselves. The performance studies for these accidents provide technical details about the reconstructions, and they note that periods when airplanes are obscured from a pilot’s nominal field of view “underscore the importance of moving one’s head (and occasionally lifting and dipping the wings) so as to see around structural obstacles when searching for traffic.”

Readers can also watch animations of cockpit display of traffic information (CDTI) displays for each of the airplanes involved in these midair collisions. The animations depict the information that these radar-like displays, fed by ADS-B, could have presented to the pilots involved. Had the airplanes been equipped with CDTI, the pilots could have been made aware of the presence and relative locations of the conflicting traffic minutes before the collisions.

In general, the timely and information-rich traffic picture offered by a CDTI can greatly improve a pilot’s ability to detect traffic threats and avoid a collision without aggressive maneuvering. We issued a safety alert, titled, “Prevent Midair Collisions: Don’t Depend on Vision Alone,” to encourage pilots to learn about the benefits of flying an aircraft equipped with technologies that aid in collision avoidance.

Much of flying is an exercise in mitigating or engineering out risk. Pilots are trained, examined, and reviewed; aircraft are certified and maintained; checklists are used; flights are planned; weather is studied. Great effort is made to leave little to chance. However, when it comes to collision avoidance in VMC, we wink at risk management (“see-and-avoid!” “Keep your head on a swivel!”), when the reality is that we rely in great measure on luck. It’s a big sky, and it would be hard to hit somebody if you tried. The odds are against a collision, but on occasion, disaster strikes.

Technologies such as CDTI provide rational risk reduction for the VMC collision avoidance problem. Guardian angels will never lack for work, but tools such as CDTI can help us to make their jobs a little easier.

Inside the NTSB’s General Aviation Investigative Process

Addressing Medical Issues

By Dr. Nicholas Webster, NTSB Medical Officer

This is the second blog in a new series of posts about the NTSB’s general aviation investigative process. This series, written by NTSB staff, explores how medical, mechanical, and general safety issues are examined in our investigations.

The NTSB investigates every aviation accident in the United States. In each investigation, we look at the roles of the human, the machine, and the environment. By learning about the factors that cause an accident, we can make recommendations to prevent similar accidents in the future.

I am one of two medical officers (physicians) at the NTSB who work closely with investigators in all modal offices. When an investigator-in-charge (IIC) is concerned that operator medical issues, drugs, or toxins may have affected performance, he or she coordinates with us to study the medical aspects of the event. The medical officers review medical documents, toxicological testing results, and sometimes autopsy reports of those involved in accidents. In conjunction with the investigative team, we help determine if operator impairment or incapacitation contributed to the cause of the accident, then we help craft language to explain to the public the nature and significance of the medical issues and how they affected the operator and contributed to the accident’s cause. We also work closely with the Board’s biodynamics and survival factors experts to help evaluate accident-caused injuries and determine what changes could be made to prevent future injuries.

The resulting information is presented in a medical factual report, which documents all pertinent medical issues and any potential hazards that the medical issues posed. To ensure accuracy, these fact-based scientific reports are peer reviewed by the investigative staff before they are published as part of the public docket. The medical, factual, and operational details of each event are then analyzed by the investigatory team, which determines probable cause by consensus, peer review concurrence, and Board authority. The probable cause represents the most likely explanation for the event given all available evidence.

Two recent cases have garnered some attention in the general aviation (GA) community, both involving fully functional airplanes operating in manageable weather. In these cases, both pilot action (error or impairment) and pilot inaction (incapacitation) can lead to an accident. In these cases, we found that the pilots were operating in a relatively low-workload environment and had the skill and experience necessary to safely complete the flights. On the other hand, medical data showed that both pilots had severe heart issues that could cause sudden incapacitation without leaving a trace.

The first accident occurred on April 11, 2015, when an experimental Quad City Challenger II airplane crashed into terrain near Chippewa Falls, Wisconsin. The 77-year-old pilot died and the airplane was substantially damaged. The pilot had the skill and experience to operate the airplane in visual conditions. According to witnesses, while the airplane was on the downwind leg of the traffic pattern at the pilot’s home airport, it entered a steep dive that continued until it struck the ground in an open field. Investigators found no evidence of preexisting mechanical concerns and, based on the propeller damage, determined that the engine was producing power at impact. Operational evidence also strongly supported pilot incapacitation.

The pilot had a history of coronary artery disease, which was treated by multivessel bypass surgery. He also had high blood pressure, elevated cholesterol, and hypothyroidism, which were controlled with medications. The autopsy showed that the pilot had an enlarged heart; severe multivessel coronary artery disease (greater than 80-percent occlusion of all vessels), with coronary artery bypass grafts and complete occlusion of two bypass vessels; scarring of the ventricular septum, indicating he had had a previous heart attack; and active inflammation of the anterolateral wall of the left ventricle of his heart. These findings, particularly the large scar and active inflammation of the heart muscle, placed the pilot at high risk for an irregular heart rhythm, which can easily cause decreased blood to the brain and result in fainting without leaving further evidence at autopsy.

Additionally, according to the Chippewa County Coroner Death Report, the cause of death was blunt force trauma. However, the examining pathologist further stated, “the most likely scenario to explain [the pilot’s] death is that he suffered an arrhythmia secondary to myocarditis.” These findings are discussed in detail in the medical factual report. Based on the available evidence, we determined the probable cause of the accident to be the pilot’s incapacitation due to a cardiovascular event, which resulted in a loss of control and subsequent impact with terrain.

The second accident of note was the crash into terrain of a homebuilt Europa XL airplane on June 26, 2015. As in the previous case, the pilot died and the airplane was substantially damaged. In this accident, the 72-year-old pilot also had the skill and experience needed to successfully complete the flight, especially given that it was a clear day and he was operating under visual flight rules.

The airplane crashed under power in a steep, nose-down, slightly inverted attitude in an open field about a half mile from the end of the runway, slightly to the right of an extended centerline. According to the IIC, there was no evidence of preexisting mechanical concerns, the engine was operating at impact, and the operational evidence suggested pilot incapacitation.

The pilot had a history of severe coronary artery disease, which was treated with multivessel bypass surgery, stents, and medication. Additionally, he had elevated cholesterol and high blood pressure, which were treated with medications. Since his last medical certification examination, an exercise stress test showed no significant changes, but a cardiac catheterization report documented that his coronary artery disease had progressed, resulting in 90‑percent occlusion of the left anterior descending coronary artery and impaired blood flow to a part of the heart muscle. Additionally, the autopsy identified multivessel coronary artery disease treated with patent coronary artery bypass grafts, and documented up to 70-percent occlusion of the left anterior descending coronary artery.

These findings are discussed in detail in the medical factual report. The pilot’s severe progressive coronary artery disease and the impaired blood flow to an area of his heart muscle placed the pilot at high risk for an acute cardiovascular event such as a heart attack, anginal attack, or acute arrhythmia. Any such event would likely cause a sudden onset of symptoms such as chest pain, severe shortness of breath, palpitations, or fainting, and would leave no evidence visible on autopsy if death occurred in the first few minutes.

The Mahoning County Coroner Autopsy Report cited multiple blunt force injuries as the cause of death, with coronary artery disease and chronic hypertension contributing to the cause of death. Again, although the pilot died of blunt force injuries, the evidence supports our finding that the accident sequence was likely initiated by his incapacitation due to a cardiovascular event.

These cases illustrate how we integrate medical findings into our investigations. We also provide interested parties with links to publicly available, detailed information that supports our findings. In both of the cases described here, the medical factual reports document significant medical issues in pilots who were operating under sport pilot rules; however, we only determined the medically related probable causes after thorough, scientific, peer-reviewed analysis of all the available facts concerning the human, the machine, and the environment.

Our goal is to identify medically related hazards that may be causal to or resultant from the accidents we investigate, and then work with the experts on the investigative team to develop mitigation strategies, which take the form of safety recommendations, that target and eliminate these hazards and improve transportation safety.

Inside the NTSB’s General Aviation Investigative Process

By Member Earl F. Weener

This is the first in a new series of posts about the NTSB’s general aviation investigative process. This series, written by NTSB staff, will explore how medical, mechanical, and general safety issues are examined in our investigations. I hope you take time to read these posts and, in doing so, come away with a greater understanding of the NTSB, our processes, and our people.

It has been my ongoing honor and privilege to serve as a Member of the NTSB over the past seven years, and I’ve been impressed by the diverse professionals who make up the NTSB staff. They work in different modes—rail, highway, pipeline, marine, and aviation—and specialize in engineering, human factors, medicine, safety outreach, and recorders, to name a few, but they all share a common goal: to protect the traveling public through recommendations aimed at improving transportation safety.

The NTSB is made up of approximately 430 dedicated employees who have a wide range of educational backgrounds and relevant experience. Our ranks include MDs, JDs, and Ph.Ds. Among our investigators, we count former members of law enforcement, industry professionals, and technical experts. When we investigate an accident, a multidisciplinary team is selected to fit the needs of the investigation.

Member Weener and investigators at the scene of the July 2013, crash of a de Havilland Otter Air Taxi, in Soldotna, Alaska

I’m often asked how the NTSB—particularly our crash investigation process—works. The NTSB is required by law to investigate every aviation incident in the United States, and our aviation safety staff investigate more than 1,200 aviation events each year. Our investigative process looks at three factors—human, machine, and environment—to determine the probable cause of accidents and incidents. This process has evolved during our 50 years, leveraging the skills, talents, and professionalism of our people, who use the latest investigative techniques and tools to find facts, analyze those facts, and determine why and how an accident happened.

Investigators consider what may have caused or contributed to the events of every accident. They look for issues in areas such as mechanical failures, operations, and weather conditions. They doggedly work to recover all onboard recorders and other sources of data, even when those recorders may be severely damaged. They also consider pilot performance, collecting evidence regarding possible fatigue, medical fitness, prior training opportunities, and specific aircraft experience.

Evidence is gathered through cooperation with pilots, witnesses, law enforcement officials, the FAA, airport officials, industry, and other stakeholders; in extreme cases, our staff can also issue subpoenas to obtain needed evidence. Investigations cannot and do not try to answer every question of why and how, but focus on questions of what caused the accident, or made it worse. Probable cause is the factor—or factors—that, based on all available evidence, the Board concludes most likely resulted in the accident. It generally takes around a year to produce a final report, which includes a probable cause and contributing factors.

Based on our investigations and special studies, we issue safety recommendations to regulatory agencies, industry, and other parties to an investigation who are positioned to implement our suggestions and improve transportation safety. The NTSB isn’t a regulatory agency, so we cannot compel compliance with our recommendations; however, of the more than 14,500 safety recommendations issued in our 50-year history, more than 80 percent are acted upon favorably. This is testimony to the NTSB’s diligence, investigative acumen, and commitment to transportation safety.

Looking back over the years and contemplating the NTSB’s contributions, I am proud to see that transportation safety has, in fact, improved greatly—especially in commercial aviation. We have seen significant improvements in aircraft crashworthiness; the introduction of life-saving technologies, such as collision avoidance and ground proximity warning systems; implementation of safety policies and regulations aimed at preventing pilot impairment, distraction, and fatigue; and emphasis on safety management systems and enhanced flight crew procedures. NTSB investigations identified the need for these advancements and helped incentivize remarkable safety improvements. Modern commercial aviation is safer now than ever before.

I often quote author Douglas Adams, who tells us that people are almost unique in their ability to learn from others, but remarkable for their resistance to doing just that. You may have heard the old saying, “knowledge is power.” We believe “knowledge is safety.” I hope you take a moment to learn about the NTSB’s investigative process in the next several blog posts, and that you come away with a greater understanding of how we at the NTSB strive to turn our knowledge into safer transportation.

A Message to the International Aviation Community: Don’t Get Complacent

By Dennis Jones, Acting Managing Director

Acting Managing Director Dennis Jones talks about the issues affecting the aviation industry and needed safety improvements

Recently, I had the opportunity to address aviation experts at the 6th World Civil Aviation Chief Executives Forum in Singapore. This forum is a unique gathering of aviation leaders who meet to discuss the latest developments and issues affecting the global aviation industry and to exchange experiences, insights, and ideas. I spoke on a panel with colleagues from safety agencies across the world. Our topic was “Ensuring Oversight, Rethinking Safety.” We discussed the future role of safety regulation and the challenges facing safety management as the field continues to grow and develop. I was honored to share my thoughts on this topic because my entire career has been focused on improving safety, both as an investigator and manager with the NTSB for nearly 40 years and as a pilot.

Looking at the progress we have made in the world of commercial aviation here in the United States, one might say we have reached our pinnacle. Aviation is now the safest it has ever been, and we are experiencing a period of zero fatalities in the commercial sphere. But we must not get complacent; we must continue to grow and learn.

Although the aviation industry can share among itself the challenges we have overcome to improve transportation safety, we can also learn a lot from other modes of transportation, as well. For example, in rail, companies are installing in-cab video to monitor operator and crew behavior and to develop best practices to improve safety; aviation could—and should—do the same. At the same time, as more driver assistance technologies are installed in vehicles of all types, and fully automated vehicles are already being tested, the highway community could learn from aviation’s experience with using automation within its operating environment.

Avoiding complacency means keeping your eyes open, receiving and sharing information, and always being ready to respond. As a multimodal investigative agency, we have seen too many ways in which disasters can occur, and some have involved complacency—becoming too bored or familiar with standard operating procedures, which leads to a lack of interest or desire to follow the established procedures. By issuing safety recommendations, such as those focused on procedural compliance, we try to urge operators to avoid this risk and a subsequent tragic outcome.

Safety is a journey, not a destination. Although, we are seeing zero fatalities in commercial aviation, our general aviation community is still suffering losses every day, sustaining nearly 400 fatal accidents a year in the US alone. Why? We must keep asking the questions and seeking the answers to bring this number down to zero.

Acting Managing Director Dennis Jones and fellow Ensuring Oversight, Rethinking Safety panelists at the 6th World Civil Aviation Chief Executives Forum

The NTSB does not issue regulations; we are focused on solving the accident mystery and issuing appropriate recommendations to improve safety and prevent future incidents. Regulations may be one way to do this, but we have always understood that safety goes beyond rulemaking. One tool we use to call attention to the issues we can all act on is our Most Wanted List of transportation safety improvements. The Most Wanted List keeps us focused on our key safety priorities and is one way to avoid complacency on those most important live-saving issues. Despite how many regulations are in place, if an operator or individual doesn’t embrace safety, there is always an increased risk for an accident.

To continue the progress we’ve made, to ensure a safe transportation system for the traveling public, we must admit our own responsibility and role in improving safety, and we must work collaboratively: investigators, engineers, CEOs, pilots. Safety can only be achieved through worldwide collaboration and a continued invested interest in learning, growing, improving, and saving lives.

Don’t Press the Envelope

By Mike Folkerts

Loss of control in flight—when a pilot fails to maintain or regain control of an aircraft—is the leading cause of general aviation fatalities. From 2011 to 2015, nearly half of all fatal fixed-wing accidents in the United States involved pilots losing control of their aircraft, resulting in 819 fatalities. Far too many NTSB investigations have shown how a loss of aircraft attitude control is often preceded by the loss of a pilot’s mental attitude control.

April 27, 2013, Piper PA-28R-180 airplane crash near Norfolk, Nebraska.
April 27, 2013, Piper PA-28R-180 airplane crash near Norfolk, Nebraska.

In the fatal accidents that I have investigated, this loss of mental control seems to be a conscious decision by the pilot to “press the envelope”—a term made famous in the 1983 film The Right Stuff, an adaptation of Tom Wolfe’s best‑selling book about the military test pilots who became Project Mercury astronauts. As the United States sought to achieve supersonic flight and put a human on the moon, these test pilots pressed the envelope, pushing the boundaries of both aircraft and human performance. Their efforts were based on national objectives and security, and many of these aviators paid the ultimate price in that pursuit.

Unfortunately, in far too many general aviation accidents, pilots choose to press the envelope for relatively minor (and often selfish) reasons, like “pressing the weather” to get home for dinner, flying at low altitude or maneuvering aggressively for an extra boost of adrenaline, or “pressing a known aircraft issue” to get a job done. Although a “git-r-done” attitude is certainly commendable, pilots too often forget to trust the little voice inside that warns them to steer clear of unwarranted risks, or they fail to guard against the temptation to make extreme efforts to please or impress others. General aviation flying very rarely requires the need to press the envelope, and pressing far too often ends in a tragic loss of control.

The NTSB is so concerned with this phenomenon that, for the last 3 years, we have placed “Prevent Loss of Control in Flight in General Aviation” on our Most Wanted List of transportation safety improvements to help bring attention to the issue. Last week, NTSB Board Member Earl Weener even attended the Sun ‘n Fun International Fly-In—one of the world’s largest general aviation enthusiasts’ training events—to talk to pilots about the dangers of losing control.

Whatever a pilot’s motivation may be for wanting to press the envelope, in general aviation, it’s not worth risking loss of control. Never underestimate the connection between mental attitude and aircraft attitude.

Mike Folkerts is an aviation safety investigator in the NTSB Office of Aviation Safety.

 

Fahrenheit 1,100: Lithium Batteries in Aviation

By Robert L. Sumwalt

There is no place for a fire on an airplane. And if there is a fire, it should not overwhelm fire-suppression equipment.

No-brainer, right?

Poster image for Most Wated List issue area Ensure the Safe Shipment of Hazardous MaterialsHere is another no-brainer: lightweight, portable energy is necessary for our modern way of life. Smartphones, laptops, power tools, and even some vehicles depend on lithium batteries. The ubiquitous nature of these modern electronic devices has, in turn, increased the need to ship the batteries that power them.

The same high-energy density that makes lithium batteries such a great way to store electricity can also introduce a fire hazard. A fault in the battery, such as a flaw in the manufacturing process, can cause a fire. Even if a fire starts elsewhere, a lithium battery makes for formidable fuel. When a fire spreads from cell to cell within a lithium-ion battery, it can burn at 1,100 degrees Fahrenheit.

While international air regulations prohibit bulk shipment of lithium batteries on passenger airplanes, the NTSB investigated one cargo aircraft fire in the U.S., and we participated in two foreign-led accident investigations of cargo aircraft where lithium battery fires were suspected.

In late 2010, UPS flight 006 crashed minutes after takeoff from Dubai, UAE. The crew reported an onboard fire but was unable to land their 747 before fire consumed the aircraft. Both crewmembers lost their lives, and the aircraft and cargo was destroyed. The investigation found that a large fire that developed in palletized cargo on the main deck caused the crash. This cargo consisted of consignments of mixed cargo that included a significant number of lithium-type batteries and other combustible materials. The fire escalated rapidly into a catastrophic uncontained fire. The hazardous smoke and fumes entered the cockpit and upper deck simultaneously, obscuring the crew’s view and creating a toxic environment.

Ten months later, Asiana Airlines flight 991, a 747 cargo flight, crashed on its way from Incheon, South Korea, to Shanghai, China. The two pilots on board the aircraft died. The NTSB assisted Korea’s Aviation and Railway Accident Investigation Board (ARAIB) in investigating the crash. The ARAIB determined that a cargo fire that developed on or near two pallets containing dangerous goods (hazardous materials), including hybrid-electric vehicle lithium-ion batteries and flammable liquids, caused the crash. The ARAIB could not pinpoint the cause of the fire, but it determined that the flammable materials and lithium-ion batteries that were loaded together were a contributing factor.

This year, we recommended that the Pipeline and Hazardous Materials Safety Administration (PHMSA) take action in response to the 2011 crash. We asked PHMSA to take the following steps:

PHMSA has suggested other actions that could also meet our intent. Whatever solution

PHMSA develops, U.S. aviation cannot ignore this potential hazard.

Thankfully, lithium battery failures are rare, and new research and meaningful efforts are underway to make them rarer still. On April 11 and 12, 2013, we conducted a public forum on lithium battery safety. Since then, the Federal Aviation Administration (FAA), in conjunction with the Commercial Aviation Safety Team, has established a joint government–industry working group. The group is developing ways to make lithium battery fires less likely in aviation and to reduce the consequences in case they do occur.

We have issued several other lithium battery-related safety recommendations to the FAA and PHMSA encouraging them to share critical safety lessons learned, implement mitigations, and conduct research into safety improvements. Other NTSB recommendations about the certification and testing of lithium batteries aim to make such fires less likely.

We continue to share our lithium battery investigation findings and advocate safety recommendations. We participate in the UL-initiated Battery Safety Council and attend industry outreach events and seminars, such as the NASA battery forum and seminars from the Knowledge Foundation.

Lithium batteries are not going away; they are far too useful. But we must ensure that each and every shipment of lithium batteries poses minimal safety risk. That is why our Most Wanted List calls on regulators and others to Ensure the Safe Shipment of Hazardous Materials, including lithium batteries in aviation.

Just the Facts

By Sharon Bryson

The NTSB is an independent federal agency charged with improving transportation safety, and a significant part of that mission is accomplished by investigating every civil aviation accident and significant accidents in other modes of transportation. Fast approaching its 50 anniversary, this small agency takes pride in its independence, transparency, and collaborative approach to accident investigations. As a key measure of our effectiveness, we maintain strong working relationship with all transportation stakeholders. We work hard to build and maintain the trust and confidence of those stakeholders while we carefully, thoroughly and independently gather all the facts surrounding an accident to maintain credibility with the public.

You may have had the opportunity to view the recently released movie about the Jan. 15, 2009, US Airways flight 1549, ditching on the Hudson River.  (NTSB report title: “Loss of Thrust in Both Engines After Encountering a Flock of Birds and Subsequent Ditching on the Hudson River”). As an employee of the National Transportation Safety Board I can appreciate the movie’s treatment of the ditching of U.S. Airways Flight 1549 – it’s certainly a movie-worthy moment in aviation history. However, the movie is a fictionalized version of the NTSB’s investigation of the accident, and as such, it portrays the NTSB as the antagonist. That’s unfortunate because it misrepresents the purpose of our investigation and in doing so, undermines the important safety lessons learned and recommendations that we issued.

The purpose of the investigation was to gather the facts surrounding the accident, understand what happened, and make recommendations to prevent recurrence and improve aviation safety. Thankfully, this accident had a successful outcome because of the performance of a very skilled crew and the exceptional rescue efforts by many that day. As good as the outcome was, the NTSB knew there was much to learn from the accident, as there is in every accident we investigate.

The ditching of US Airways flight 1549 presented the NTSB with one of the best moments to learn ‘the facts’ and recommend improvements to reduce future accidents because everyone survived – and isn’t that the best time and the best way to improve safety?

The NTSB issued its report May 4, 2010, along with 35 safety recommendations designed to keep you and your loved ones safer.

The facts of this investigation, including the final accident report, related safety recommendations, a webcast (and associated transcript) of the June 2009 three–day investigative hearing, nearly 4000 pages of investigative materials from the accident docket, and an accident animation, are publicly available on the NTSB’s web page for the accident so you can too, get the facts.

Sharon Bryson is the Director of the NTSB’s Office of Safety Recommendations and Communications.