Lessons from Our Runway Incursion Forum

By Member Christopher Hart

On September 19 and 20, the NTSB held a Runway Incursion Forum featuring some of the industry’s foremost runway safety experts. These experts came from far and wide, and from a variety of aviation associations, companies, research organizations, government agencies, and airports. It was a very thought‑provoking event, and I believe we had the right people at the table to address an increasing trend in the most significant (Levels A and B) runway incursion events.

NTSB Runway Incursion Participants
Member Hart and NTSB staff with Runway Incursion Forum participants.

The aviation industry has proven itself to be adept at tackling challenging safety issues. In the early 1990s, the fatal commercial aviation accident rate that had been declining for several decades began to plateau. Many safety experts concluded that further reduction in the rate was unlikely because the plateaued rate was already exemplary. Nonetheless, concerned that the volume of flying was projected to double in the next 15­–20 years—and with it, if the rate remained flat, the number of airline crashes—the industry began an unprecedented voluntary collaborative safety improvement program to further reduce the accident rate. This program was called the Commercial Aviation Safety Team, or CAST. Amazingly, CAST reduced the flat fatality rate by more than 80 percent in only 10 years.

Perhaps the most difficult challenge that we are currently facing regarding runway incursions is pursuing additional remedies in the absence of an accident. The industry is frequently accused of having a “tombstone” mentality: attempting to improve safety only when there’s a major accident. I applaud the efforts of the FAA, the general aviation community, the commercial aviation industry, and the airports, along with the front-line vigilance of the pilots, air traffic controllers, and airport operators who live and breathe this issue every day, to proactively identify ways of driving down the numbers. It’s a sign of this vigilance that they came together out of our common concern about the apparent turnaround from the previous downward trend in A and B incursions.

So, what did we learn from our forum? First and foremost, the staff who organized this event recognized one of the major lessons learned from the CAST collaboration: that everyone who is involved in a problem should be involved in developing the solution. Hence, we invited pilots, air traffic controllers, airport operators, affected industry organizations, and the regulator (the FAA), as well as those who collect and analyze the data­—in other words, everyone who is involved in the problem—to discuss their perspectives on the runway incursion problem.

Each participant emphasized the need for more and better data: data to help us identify the problems, determine what caused them, develop interventions, and determine whether the interventions are accomplishing the desired result. We need to determine how to collect better data, how to analyze the data more effectively, and, pursuing the collaboration concept, how to share the data more effectively, both with peers and with other participants in the system.

Perhaps the most challenging issues that warrant better data are the human factors issues regarding human limitations and vulnerabilities, and determining how humans can interact most effectively with rapidly advancing technologies. There has been considerable progress in understanding human factors in the cockpit, and it was interesting to hear in the forum about the development of a new program that also aims to enhance our understanding of human factors issues that affect air traffic controllers.

Participants at the forum also discussed several exciting new technologies—in the cockpit, in air traffic control facilities, at airports, and in airport ground vehicles—to help increase the situational awareness of pilots, controllers, and vehicle operators. We heard of many activities by the airport community to address “hot spots,” the places on the airport surface where runway incursions are occurring most frequently. These activities include changing procedures, improving training, adding new technologies, and making major capital improvements to modify airport geometry.

NTSB Runway Incursion Forum
Member Hart leads a roundtable discussion during the Runway Incursion Forum.

Runway incursions are increasing amidst a culture that, in the last 15–20 years, has become more sensitized to their potential danger. What is needed is both site‑specific remedies (due to the uniqueness of every airport) and systemic remedies that address the system’s commonalities. Through their presentations and active participation in our forum, it became clear to me that our forum participants refuse to wait for an accident to begin making improvements.

We heard from multiple participants that about 80 percent of runway incursions involve general aviation aircraft. Although the creation of new collaboration networks, such as the General Aviation Joint Steering Committee (GAJSC), is beginning to bring general aviation stakeholders more consistently into the runway incursion prevention conversation, we learned that the effort to bring all stakeholders to the table must continue, which is a challenge because the general aviation community is very broad and multifaceted.

I am optimistic that government, airlines, airports, and others will follow up on the most important directions that we collaboratively identified in the forum, and that they will continue to develop and deploy new solutions to the complex problem of runway incursions.

The full agenda, speaker biographies and a recording of the forum are available at https://go.usa.gov/xRhpC.

Inside the NTSB’s General Aviation Investigative Process

The Nuts and Bolts

By Aaron Sauer

This is the sixth 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 public’s image of our agency is often based on the iconic blue and yellow NTSBNTSB Investigators Onscene jacket they see at accident scenes. What’s less well known is that examining and documenting on-scene evidence is just one step in an exhaustive process to gather all available information, determine a cause, and recommend any changes that can prevent similar accidents.

Since 2014, 12 percent of general aviation accidents—about three accidents every week—have involved a power plant malfunction. These malfunctions may include a fuel issue, component failure, or improper maintenance.  As an NTSB air safety investigator, I investigate such mechanical malfunctions, gather the facts of the investigation, and ultimately help determine the probable causes of accidents.

After the on-scene phase of the investigation is complete, the airplane wreckage is often recovered by professional recovery services and stored in a secure location until we determine if further NTSB investigation is needed. When circumstances, such as a large hole in the engine crankcase or the in-flight loss of a propeller, indicate that further examination is necessary, we work with the airframe, engine, and component manufacturers. These entities serve as parties to our investigation, providing technical expertise on their product. If required, we coordinate a follow-up plan to examine the aircraft wreckage in greater detail. At the accident scene or recovery facility, our investigators examining the machine determine the scope of follow-up based on any anomalies discovered.

In some accidents involving a reported loss of engine power, the initial examination (typically a 100-hour inspection) turns up no obvious anomalies. At this point, one of the best and most telling follow-up activities is to attempt an engine test run. Engine test runs may be performed at a recovery facility or at a manufacturer’s facility. A successful engine test run is a critical piece of information that may lead the investigation down another path.

When, upon initial examination, the investigator observes an engine issue consistent with an internal mechanical failure, it’s typical to disassemble the engine at the manufacturer’s facility or the recovery facility under NTSB supervision. Examining an engine at the manufacturing facility often provides the advantage of having available engineering staff, historical data and drawings, and proper test equipment for the engine components.

Once at the manufacturer’s facility, the investigation team (typically including NTSB, FAA, and airframe, engine, and component manufacturer personnel) determines the plan or approved test procedure for the detailed investigation. The scope of the investigation is determined based on the known facts and circumstances of the accident, the condition of the engine and components, and the work required to confirm the failure. It’s important to note that, although the parties work collaboratively, the NTSB has the final say if there is any disagreement in the investigation process.

Engine functional testing, partial disassembly, and full engine disassembly are the most common investigation techniques used to determine the cause of a failure or malfunction. Disassembly helps us identify fractured or broken parts, which are then documented and set aside for even further examination.

Most manufacturers have their own materials laboratory, metallurgists, and engineers. At this point and with the team present, our investigators may elect to use the manufacturer’s material laboratory for a preliminary examination to obtain a quick analysis of the failure mode, then forward the parts to our materials laboratory in Washington, DC, for a detailed metallurgical examination.

Even observers with a solid understanding of our processes beyond the on-scene images might not understand the many ways that NTSB investigations can improve safety. Even when all signs point to a mechanical malfunction, our investigative process still looks at two other factors: human and environment. When an accident involves reported loss of engine power, we gather information about the pilot and aircraft owner—documentation from the scene, aircraft records, and Federal Aviation Administration (FAA) records. We interview witnesses, visit and examine maintenance facilities, and meet with manufacturers. When necessary, we conduct follow-up examinations and interviews. If FAA inspectors handle the initial on-scene observations, we work hard to guarantee that our two agencies communicate effectively.

When the fact-gathering phase of the investigation is complete, our investigators compile all the relevant factual information, complete a detailed factual report, and create a public accident docket. For an engine failure accident, the docket may include engine reports, materials laboratory reports, aircraft records, and historical engine safety information in the form of service bulletins and airworthiness directives.

Many people understand that we may make recommendations at any point during an investigation, but sometimes our investigations also result in other actions to improve safety. For example, depending on the nature of the material failure, an NTSB investigator may work with the FAA or the manufacturer to issue a manufacturer service bulletin, service letter, safety notice, or a potential airworthiness directive. The safety action taken by the FAA or manufacturer depends on the failure’s cause, fleet exposure, and the potential safety awareness benefit of each product.

Over my 17 years as an NTSB investigator, I’ve investigated numerous engine-failure–related accidents that resulted from human error and material failure. Despite the varied causes and outcomes of these accidents, one fact stands out: proper maintenance is the best way to avoid catastrophic consequences. Following manufacturer-recommended maintenance practices and procedures and adhering to basic maintenance principles can prevent accidents.

Remember: SAFETY is NO ACCIDENT!

All accident reports and public accident dockets are available on the NTSB website:  www.ntsb.gov.

 

¿Qué se puede hacer para mejorar la seguridad del transporte de los trabajadores agrícolas migratorios?

Por Jennifer Morrison

Este Domingo pasado marcó el aniversario del choque de carretera más mortífero de la historia de Estados Unidos. Hace cincuenta y cuatro años, el 17 de septiembre de 1963, un autobús improvisado que transportaba 58 trabajadores agrícolas migratorios chocó con un tren de carga cerca de la ciudad de Chualar, California (consulte la figura 1) 32 personas murieron y 25 sufrieron lesiones. Los trabajadores que venían en el autobús estaban regresando de un campo de trabajo después de una jornada de diez horas recolectando apio en el Valle Salinas. Los pasajeros se transportaban en dos bancos largos colocados a lo largo de un camión de plataforma que estaba cubierto con un toldo.

LA Times Headline
Titular e imagen del ejemplar del 18 de septiembre de 1963 de Los Angeles Times. En ese momento se creía que solo 27 personas habían perdido la vida pero el número de víctimas ascendió a 32.

Otro choque mortal de trabajadores agrícolas migrantes ocurrió en la década de 1970. El 15 de enero de 1974, la Junta para la seguridad del transporte nacional (National Transportation Security Board, NTSB) investigó un choque que involucró 46 trabajadores agrícolas migrantes cerca de Blythe, California. Un autobús de trabajadores agrícolas que viajaba por una carretera rural no pudo tomar una curva de la carretera y cayó al fondo de una zanja de desagüe. El autobús quedó apoyado en su lado izquierdo, parcialmente sumergido. Murieron diecinueve de sus ocupantes, incluyendo el chofer. En la mitad del último siglo se han efectuado numerosas mejoras en la seguridad del transporte y sin embargo ocurren choques catastróficos y la seguridad de los trabajadores agrícolas migrantes continúa siendo un problema.

Específicamente, durante el período de ocho meses desde noviembre de 2015 hasta julio de 2016, la NTSB investigó tres choques con numerosas muertes en los cuales 16 personas murieron y otros 57 resultaron lesionados. La mayoría de los fallecidos y lesionados eran trabajadores agrícolas migrantes que se transportaban hacia o desde granjas. La finalidad de nuestra investigación sobre estos choques es conocer sobre estas tragedias y responder la pregunta importante: ¿Qué se puede hacer para mejorar la seguridad del transporte de los trabajadores agrícolas migrantes?

Esta semana la NTSB abrirá el expediente público de 1,125 páginas de información documentando nuestra investigación en curso sobre el choque del 2 de julio de 2016 cerca de St. Marks, Florida. El choque involucró un autobús de trabajadores agrícolas que transportaba más de 30 personas desde una granja en Georgia a Belle Glade, Florida. El autobús no se detuvo en la intersección de la carretera estatal 363 y la autopista US 98, la cual estaba marcada con un cartel de señal de pare y una luz intermitente en rojo de señal de “pare”, y este fue impactado por un vehículo de tipo combinado de semirremolque con tractor de remolque. Después del choque se produjo un incendio y el chofer del camión y tres pasajeros del autobús perecieron (Consulte la figura 2).

El 28 de noviembre de 2017, la NTSB llevará a cabo una reunión pública de la junta para discutir las conclusiones de la investigación del choque de St. Marks, su causa probable y las recomendaciones de seguridad destinadas a prevenir choques futuros.  En la reunión la NTSB también revisará las circunstancias de los choques de Little Rock, Arkansas y Ruther Glen, Virginia (Consulte la figura 2).

Investigation Images
(Parte superior) Autobús y camión involucrados en el choque de St. Marks, Florida en su etapa final (Fuente:  Patrulla de carreteras de Florida). (Parte inferior izquierda)  Autobús involucrado en el choque de Little Rock, Arkansas mostrando la porción de la parte posterior faltante y el techo dañado.  (Parte inferior derecha) Camioneta para 15 pasajeros involucrada en el choque Ruther Glen, Virginia mostrando el techo deformado.

El choque de Little Rock ocurrió el 6 de noviembre de 2015, cuando un autobús que transportaba 20 trabajadores agrícolas desde Michigan a Texas se salió de la Interestatal 40 y chocó con una barrera de concreto.  El choque con la barrera ocasionó que el autobús se montara en el costado de la barrera y el techo del autobús impactara la columna de un puente que apoyaba el viaducto de la autopista. Como resultado del choque, 6 pasajeros del autobús perecieron.

El choque de Ruther Glen ocurrió el 8 de junio de 2016, cuando una camioneta para 15 pasajeros que transportaba 16 ocupantes, la mayoría de los cuales eran trabajadores agrícolas migrantes, se salió de la Interestatal 95. La camioneta se desplazó hacia la derecha por todos los canales de circulación e impactó a otro carro de pasajeros antes de volcarse varias veces.  Seis de los pasajeros de la camioneta salieron impelidos y fallecieron.

Al examinar la supervisión de los transportistas federales y estatales que participan en el transporte de trabajadores agrícolas, los mecanismos de las regulaciones de seguridad, la divulgación y la educación de la comunidad agrícola y las mejores prácticas de los estados individuales, esperamos desarrollar recomendaciones de seguridad para mejorar la seguridad del transporte de los trabajadores agrícolas migratorios y evitar tragedias futuras.

Asista a la reunión del 28 de noviembre de 2017, en persona o mírela en la transmisión por la web donde se tratarán las investigaciones de los choques de St. Marks y otros con las propuestas a la pregunta: ¿Qué se puede hacer para mejorar la seguridad del transporte de los trabajadores agrícolas migratorios?

Jennifer Morrison es una investigadora encargada de la oficina de la NTSB para la seguridad en las carreteras

 

 

 

What Can Be Done to Improve Transportation Safety for Migrant Farmworkers?

By Jennifer Morrison                                                                                     

This week marked the 54th anniversary of the deadliest highway crash in US history. On September 17, 1963, a makeshift bus carrying 58 migrant farmworkers collided with a freight train near the city of Chualar, California (See Figure 1), killing 32 people and injuring 25. The workers on the bus were returning to a labor camp after a 10‑hour shift harvesting celery at farms in the Salinas Valley. The passengers were riding on two long board benches that ran the length of a canopy-covered flatbed truck.

LA Times Headline
Headline and image from the September 18, 1963, issue of the Los Angeles Times. At the time only 27 people were thought to have died; the final death toll rose to 32.
Another deadly migrant farmworker crash occurred in the 1970s. On January 15, 1974, we investigated a crash involving 46 migrant farmworkers near Blythe, California. A farm labor bus traveling on a rural road failed to negotiate a curve in the roadway and vaulted into the bottom of a drainage ditch. The bus came to rest on its left side, partially submerged. Nineteen of the bus occupants, including the driver, died.

The last half century has seen many improvements in transportation safety, yet catastrophic crashes still occur, and the safe transportation of migrant farmworkers remains an issue. During the 8-month period from November 2015 through July 2016, we responded to three multifatality crashes in which 16 people were killed and 57 others were injured. Most of those killed and injured were migrant farmworkers being transported to and from farming locations. We investigate these crashes to learn from them and answer the important question:  What can be done to improve transportation safety for migrant farmworkers?

Today, we released more than 1,100 pages of documents related to our ongoing investigation into the July 2, 2016, crash near St. Marks, Florida, involving a farm labor bus and a truck-tractor semitrailer combination vehicle. The bus, which was transporting more than 30 farmworkers from a farm in Georgia to Belle Glade, Florida, failed to stop at the intersection of State Road 363 and US Highway 98—which was marked by a stop sign and flashing red “stop” signal—and was struck by the truck-tractor vehicle. A postcrash fire ensued, and the truck driver and three bus passengers died (See Figure 2).

On November 28, 2017, we will hold a public Board Meeting to discuss the findings of the St. Marks crash investigation, its probable cause, and safety recommendations aimed at preventing future crashes. We will also review the circumstances of crashes in Little Rock, Arkansas, and Ruther Glen, Virginia (see Figure 2).

St Marks Blog
(Top) Bus and truck involved in the St. Marks, Florida, crash at final rest (source: Florida Highway Patrol). (Lower left) Motorcoach involved in the Little Rock, Arkansas, crash showing the damaged, missing rear portion of the roof. (Lower right) 15-passenger van involved in the Ruther Glen, Virginia, crash showing the deformed roof.
The Little Rock crash occurred on November 6, 2015, when a motorcoach transporting 20 farmworkers from Michigan to Texas departed Interstate 40 and collided with a concrete barrier. The collision resulted in the bus climbing up the side of the barrier, its roof impacting a bridge column that supported a freeway overpass. As a result of the crash, six bus passengers were killed.

The Ruther Glen crash occurred on June 18, 2016, when a 15-passenger van transporting 16 occupants, most of whom were migrant farmworkers, departed Interstate 95. The van swerved right across all lanes of travel and impacted another passenger car before overturning multiple times. Six of the van passengers were ejected and died.

By looking at factors such as federal and state oversight of motor carriers engaged in agricultural worker transportation, enforcement of safety regulations, outreach and education in the agricultural community, and individual states’ best practices, we hope to develop safety recommendations that will improve the transportation safety of migrant agricultural workers and prevent future tragedies.

Attend the November 28 meeting in person or watch via webcast as we attempt to determine, based on our findings from the St. Marks accident and similar crashes, what can be done to improve transportation safety for migrant farmworkers.

Jennifer Morrison is an Investigator-in-Charge in the NTSB Office of Highway Safety.

 

 

Are you Making the Right Choice?

By Stephanie Shaw

Did you know that motor vehicle-related deaths are a leading cause of unintentional death for children in the United States?

Did you know that in 2015, nearly 500 children under age 7—many of whom were unrestrained—were killed in motor vehicle crashes?

Did you know that children are safest when using a child safety seat or booster seat, but nearly half of child car seats and booster seats are used incorrectly?

For parents, these statistics might be terrifying and overwhelming. As a parent and volunteer child passenger safety technician, I take comfort in knowing that the best way to protect my own children is to properly use age-appropriate child car seats and booster seats. But with so many messages out there and so many options for child car seats and booster seats, how does the average parent choose the right one?

Today, I want to share the answers to some of the questions I’ve gotten from parents and caregivers regarding car seats and booster seats.

Q. Which child car seat is the safest?

A. All child car seats must meet the same federal safety standards, but car seat designs vary. That’s why it’s critical to look for a seat that’s recommended for your child’s height and weight.

Q. So, I just need to buy the right car seat?

A. Not so fast. Buying the right seat for your child is the first step, but it still falls on the adult to install and use the car seat properly every time.

Q. How do I install and use a child car seat?

A. Read carefully and follow the instructions that came with your car seat, and also consult your vehicle owner’s manual; both provide steps for how and where to install the seat in your vehicle. All children should ride properly secured in a car seat or booster seat in the back seat. If you would like help installing your seat, visit Safe Kids Worldwide to locate a child passenger safety technician in your area.

Q. When do you change from rear-facing to forward-facing seats?

A. Children under the age of 2 are best protected when they are in a rear-facing car seat in the back seat, as their spine and neck are not developed enough to support their head in the event of a crash. It’s recommended that even children older than age 2 remain rear facing until they outgrow the rear-facing height or weight limit for their seat. When children outgrow a rear-facing car seat, they should use a forward-facing car seat with an internal harness and tether.

Q. When is my child ready to ride like an adult passenger?

A. Children aren’t ready to ride like adult passengers until the adult seat belt fits them properly; usually when they are 4’9” tall. Until then, they should use a booster seat. Booster seats help children fit in an adult seat belt. Children seated in a booster seat in the back seat of the car are 45 percent less likely to be injured in a crash than children using a seat belt alone. But don’t be in a rush to move your child into a booster seat or seat belt! Children are best protected when using a car seat with an internal harness.

Q. How can you tell when an adult seat belt fits a child properly?

A. A seat belt fits properly when the lap belt lies snugly across the user’s upper thighs, not the stomach. The shoulder belt should lie snugly across the user’s shoulder and chest without crossing the neck or face.

Q. When is my child old enough to sit up front with me?

A. Until your child properly fits an adult seat belt, he or she should always ride in the back seat, and should always use the right-sized child car seat or booster seat. Different-sized children need to be protected differently (read on!).

Q. What are common mistakes to look out for when using a car seat?

A. Some common mistakes parents and caregivers make include:

  • using a forward-facing child car seat too soon;
  • installing the car seat too loosely and allowing the seat to move more than 1 inch at the belt path;
  • allowing the harness straps to fit loosely so they fail the pinch test; and
  • placing the chest clip too low, rather than at armpit level.

To help avoid some of these common mistakes, read the instructions that came with your car seat as well as your vehicle owner’s manual. Reading these instructions will help you determine whether to use a seat belt or the lower anchors, and when to use the tether to secure your seat. Your car seat instructions will help you position the car seat (rear facing, forward facing, or reclined) and properly use the internal harness, chest-clip, and buckle.

Q. How can I get hands-on help?

A. You’re in luck! It’s Child Passenger Safety Week, so child passenger safety technicians and other safety professionals are hosting events nationwide where parents and caregivers can get hands-on help to ensure their child is in the most appropriate car seat, and that it is installed and being used properly. Saturday, September 23, is National Seat Check Saturday; to find an event in your community, visit www.safercar.gov. And help is also available year-round, too. Find a car seat check event or child passenger safety technician in your area to make sure you’re using the right seat, every trip, every time.

Car seats, booster seats, and seat belts are a child’s best defense against injury and death in the event of a motor vehicle crash. Be sure you’re making the right choice to protect your child!

Stephanie Shaw is an NTSB Safety Advocate in the Office of Safety Recommendations and Communications and a certified child passenger safety technician.

Behind-the-Scene @ NTSB

Welcome to the introductory episode of the newest advocacy tool from the National Transportation Safety Board!

Behind-the-Scene @NTSB will be an opportunity for our agency to share the stories of our amazing staff and highlight the exceptional work that is being done to advance transportation. Each episode will feature an interview with NTSB staff. We’ll delve into their transportation career history, discuss interesting investigations or reports that they have worked on, and share how their expertise improves safety.Behindthescene

There are many amazing and interesting facets to the work being accomplished at the NTSB and we look forward to sharing these stories.

Erik and James in action
Technical Producer James Anderson (lt) and Host Erik Strickland (rt) prepare for an episode taping.
New episodes will be available every other Thursday and will soon be available on Apple Podcasts and Google Play.

Keep up-to-date by connecting with NTSB on Twitter, Facebook, Instagram, and LinkedIn.

If you have questions about the podcast, feel free to email us at SafetyAdvocacy@NTSB.gov

Inside the NTSB’s General Aviation Investigative Process

An Aeromedical Mystery Solved

By: Clint Johnson, Chief, Alaska Region, Office of Aviation Safety

This is the fifth 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.

Clint Johnson
Clint Johnson at industry event

After nearly 20 years of investigating hundreds of aviation accidents, I recently encountered an invisible killer.

I was enjoying a late summer Saturday afternoon with my wife in Anchorage, Alaska, when my phone rang. My wife – a 20-year-veteran NTSB spouse – knew from the look on my face that our quiet weekend at home had just ended.

An Anchorage Fire Department dispatcher was calling. She reported that rescue crews were on the scene of a fatal airplane crash in a residential neighborhood only 20 minutes away.

When I arrived, I was briefed by a small army of Anchorage Police and Fire Department

hillside-plane-crash-ablaze-1024x576
Hefty Polar Cub airplane crash site

crews. Behind the wall of fire trucks, police cars, stunned residents, and TV cameras, I caught a glimpse of the inverted and burned remains of what looked like a float-equipped Piper 11 in the middle of the residential roadway.

We continued to talk as we walked toward the wreckage site. The pungent smell of burned aircraft wreckage filled the air as we proceeded past the yellow police tape. Finally, I was close enough to see that only the welded steel-tube structure and engine remained, with the fuselage and wings barely recognizable. The postcrash fire had incinerated much of the wreckage.

Witnesses had told the police that just before the accident they watched in amazement as the airplane completed two, low-level, high-speed, 360° right turns over the neighborhood – the first 150-200 feet above ground level, and the second much lower. One homeowner stated that the airplane passed over his home about 50 feet above his roof.

Witnesses also reported that the airplane’s bank angle increased significantly on the second 360° right turn; one pilot-rated witness estimated the bank at more than 60°. Witnesses also reported hearing the airplane’s engine operating in a manner consistent with high power settings throughout both 360° turns.

One man was mowing his lawn as the airplane completed the second, steep, 360° right turn. He said that the airplane flew directly over his yard, then the nose of the airplane pitched down and it began to descend rapidly. The engine rpm then increased significantly, and the wings rolled level just before the airplane impacted a stand of tall trees adjacent to his home, severing its floats.

It crashed on a neighborhood road, coming to rest inverted. About 30 seconds after impact, a fire ensued, which engulfed the entire airplane before any of the witnesses made it to the wreckage.

Sadly, after the fire department crews extinguished the fire, they found the remains of the 75‑year-old pilot and his dog still inside the incinerated wreckage.

While we all waited for the medical examiner to arrive, I began interviewing witnesses. Most concluded, or were well on their way to concluding, that the pilot was “just showing off” to someone on the ground. But the NTSB sets a high bar for conclusions. It was way too early for me to go there.

At the scene, I met a family member, along with a close friend of the pilot. Understandably upset, both reported that it was highly unusual and uncharacteristic behavior for the pilot to be flying as the witnesses consistently described to me. They went on to say that to their knowledge, the pilot didn’t know anyone in the area, but that, given the pilot’s anticipated flight route, he would have been flying over the neighborhood while on the return flight home.

Then, as the pair was preparing to leave the scene, the pilot’s friend said something in passing – something about his longtime buddy’s history of cardiac problems, which, in his opinion, caused the pilot’s erratic flight maneuvers.

I pressed him for more information, but it became clear that he wasn’t prepared to provide any additional information on the subject then and there, and I decided that this was neither the time or place to discuss it. As the pair got back into their car and slowly drove away, I knew that the following Monday morning I’d likely be attending the pilot’s autopsy.

For now, I needed to document and examine the wreckage before it was removed. This included determining control cable continuity to the flight control system, engine control continuity, and more.

The engine sustained significate impact damage, but only minimal fire damage. There were no mechanical problems that I could find on-scene that would explain what the witnesses reported. However, a much more detailed wreckage exam would be accomplished later, once the wreckage was moved to a more secure and suitable site.

On Monday morning, I found myself at the State medical examiner’s facility, meeting with the pathologist who would be working my case. I explained to her what I was looking for, and she started the exam.

The entire autopsy took over two hours to complete, and the pathologist found no conclusive evidence for medical incapacitation from an acute cardiac event. However, per standard protocol, the autopsy team took blood and tissue samples to send to the FAA’s Bioaeronautical Sciences Research Laboratory in Oklahoma City for a toxicological exam.

I knew I would not have the tox report for two to three months, but the autopsy yielded at least one more piece of valuable information: the pilot died from trauma, not the postcrash fire. Unbeknownst to me at the time, this would be an extremely important data point that would help solve the case in the end.

Over the next two weeks, I visited the wreckage two separate times at a local aircraft salvage yard. I looked for evidence that would support various theories, but nothing ever panned out. It was one dead end after another.

Then on a cold and snowy autumn afternoon, the FAA’s tox report on the pilot appeared in my e-mail. I opened it and scanned the results, and only then realized just what I had been missing all this time: Carbon Monoxide, an odorless, colorless and tasteless gas – and a silent killer of general aviation pilots.

The pilot’s carboxyhemoglobin (carbon monoxide) level was an extremely high 48%. To put these results in context, nonsmokers may normally have up to 3% carboxyhemoglobin in their blood, and heavy smokers may have levels of 10% to 15%. And according to family members, this pilot did not even smoke.

Since the pilot died of blunt-force trauma prior to the ensuing fire, it was not possible that this CO level was an effect of the fire. But it was possible that it was a cause of the crash.

I realized that over the last few months I had missed an important and somewhat elementary piece of evidence, the airplane’s exhaust system. I quickly reviewed my on-scene photos, and I could clearly see that the entire exhaust system sustained relatively minor damage in the accident.

Within 15 minutes of receiving the toxicology results, I was on my way back to the stored wreckage. I ended up bringing the entire exhaust system back to the office, muffler, heat exchanger/muff and all. Like the autopsy examiners I had met months earlier, I went to work on this simpler machinery, peeling back the heater shroud.

IMG_2192
Accident muffler can assembly

Inside I found a severely degraded muffler with portions missing, which allowed raw exhaust gases to enter the main cabin through the airplane’s heater system.

Unfortunately, neither the family or any of the pilot’s friends could find any maintenance logbooks for the accident airplane, so I was unable to determine just when the last muffler inspection was done (if ever). However, after talking with several friends of the deceased pilot, many said that he did his own maintenance, and he was not an aviation mechanic.

They went on to say that the pilot, with the help of a few other friends, installed the more powerful Lycoming O-320 engine about 5 years earlier, but none could provide any additional information about how the pilot maintained his airplane.

However, I could report directly to the family what circumstances led up to the death of their loved one, and I was able to show them the physical evidence that I found.

The NTSB’s probable cause summed it all up: “The pilot’s severe impairment from carbon monoxide poisoning in flight, which resulted in a loss of control, and a subsequent inflight collision with trees and terrain.”

Often, it takes time, patience, and knowledge of the human operator, the machine, and the environment to solve an accident mystery to provide answers.