Accident or Incident? Explaining Aircraft Damage Assessment

By Mike Hodges, Air Safety Investigator, and Clint Crookshanks, Aerospace Engineer (Structures)

When an aircraft crashes, National Transportation Safety Board (NTSB) air safety investigators and aerospace engineers must determine if the event can be classified as an accident or an incident, as defined by Title 49 Code of Federal Regulations (CFR) Part 830.

An accident is:

“…an occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight and all such persons have disembarked, and in which any person suffers death or serious injury, or in which the aircraft receives substantial damage.”

An incident is:

“…an occurrence other than an accident, associated with the operation of an aircraft, which affects or could affect the safety of operations.”

Although the determination of an accident focuses on damage as well as injuries, here we will focus on damage assessment.

So, when assessing the damage, how do we decide what’s an accident and what’s an incident? When we’re first notified about an adverse aircraft event, we begin to assess the aircraft damage. NTSB investigators and engineers attempt to obtain as much information as possible about the damage. Sometimes we’re given information that makes it obvious the aircraft sustained substantial damage, such as the photos showing the extent of the damage (see Figures 1–3). Figures 1-3 show the substantial damage as indicated by the arrows.

Figure 1. A Cessna 170 airplane sustained substantial damage to the left wing, due to ground impact after an aerodynamic stall on takeoff in Arctic Village, Alaska.

Figure 2. An Enstrom F280-F helicopter sustained substantial damage to the tail boom, during a practice run-on landing in Sodus, New York.

Figure 3. A Piper PA-24-250 airplane sustained substantial damage to the left wing, after impacting a light pole during an instrument approach in Sturgis, South Dakota.

Other times, we can’t tell the extent of damage right away and we need to dig deeper. Figures 4- 6 illustrate this scenario and show the substantial damage as indicated by the arrows. For figure 4, additional information surrounding the circumstances of the object impact, a tracked drilling unit, along with the damage sustained to the main rotor blades was obtained from the Federal Aviation Administration (FAA) and the operator. For figure 5, the airplane’s structural repair manual for the damage sustained to the right wing from the bird strike was studied during the damage assessment process. For figure 6, the interior of the fuselage had to be inspected to identify the substantial damage sustained during the hard landing sequence.

Figure 4. A Eurocopter AS 350 B3 helicopter sustained substantial damage to the main rotor blades after impacting a tracked drilling unit in Delta Junction, Alaska.

Figure 5. A Cessna 208B airplane sustained substantial damage to the right wing due to a bird strike in Sacramento, California.

Figure 6. A Beech 1900C airplane sustained substantial damage to the lower aft fuselage after a hard landing in Gambell, Alaska.

When the damage sustained is not obviously substantial, NTSB air safety investigators and aerospace engineers may take additional steps to assess wreckage, such as the following:

• Working with pilots, operators, mechanics, repair stations, FAA Flight Standards District Offices, aviation insurance adjustors, and aircraft recovery companies to obtain additional damage photographs or damage information
• Consulting the airframe manufacturer’s air safety and engineering departments
• Obtaining documents, such as the structural repair manual or illustrated parts catalog, from the airframe manufacturer
• Considering other unique factors that may determine the damage level, such as airframe fire damage or the aircraft being immersed in a body of water
• Inspecting the area in question (such as spars in wings, structural areas behind firewalls, driveshafts in helicopters, gearboxes in helicopters, etc.) once the aircraft is recovered
• Removing components, panels, or skin and using tools to access hard-to-view areas (such as mirrors or electronic borescopes)

We would also determine:

• if the damaged area is classified as a primary structure (primary structure is defined by the FAA as that structure which carries flight, ground, or pressurization loads, and whose failure would reduce the structural integrity)
• what repairs are required
• which components will be replaced to repair the damaged area
• if the aircraft’s performance or flight characteristics were affected

(The cost or feasibility of repairing an aircraft, as determined by an aircraft insurance company, will not be considered when determining whether an aircraft has sustained substantial damage.)

The damage assessment timeline can vary, depending on how obvious the damage is initially. We might make a substantial determination in a few hours, or, if additional information is needed, the damage assessment can take several weeks. If the aircraft needs to be recovered from a remote area to obtain additional information, the damage assessment could extend even longer.

Although the FAA is always a party member to our investigations, the NTSB is the final authority for determining a damage classification. For those that are involved in an adverse aircraft event, some basic knowledge can help during the assessment, such as:

• Understanding the definitions and reporting requirements in 49 CFR Part 830
• Knowing how to directly contact the NTSB
• Having multiple, high-quality, high-definition photographs from all around the aircraft, showing the aircraft in its entirety
• Having multiple, high-quality, high-definition photographs of the damaged areas, including close-ups
• Knowing what repairs are required to the damaged area, along with what components will be replaced to repair the damage (when possible)

Being involved in an accident or incident, regardless of the outcome, is stressful for those involved. The NTSB works diligently with various stakeholders to provide as many answers regarding the damage classification as possible, whether it is determined to be an accident or an incident.

Episode 43: Improve Rail Worker Safety

In this episode of Behind-the-Scene @ NTSB, we talk with Rob Hall, Director, NTSB Office of Railroad, Pipeline and Hazardous Materials Investigations and Railroad Accident Investigators, Tim DePaepe and Joe Gordon, about the 2021-2022 Most Wanted List safety item Improve Rail Worker Safety.

To learn more about the NTSB Most Wanted List and the Improve Rail Worker Safety item, visit our Most Wanted List web page.                                                                                                                                 

The previously released podcast episode featuring Tim DePaepe is available on our website.

The previously released podcast episode featuring Joe Gordon is available on our website.

Get the latest episode on Apple Podcasts , on Google Play, Stitcher, or your favorite podcast platform.

And find more ways to listen here: https://www.blubrry.com/behind_the_scene_ntsb/

Improve Rail Worker Safety

By Member Tom Chapman

The Federal Railroad Administration (FRA) and the railroad industry have recently implemented new protections to make rail passenger travel and hazardous materials transportation safer. That’s great news. However, the NTSB anticipates more accidents involving passengers and the public until our safety recommendations regarding rail worker safety are implemented. Members of train crews, maintenance-of-way employees, and mechanical workers continue to be killed or injured in preventable accidents involving train or equipment movement.

Several rail workers have been struck in recent years while conducting routine maintenance, inspection, or switching operations. Other workers are vulnerable because cars carrying hazardous materials are too close to the operating cabs carrying train crew. Although rail worker fatalities have declined overall in recent years, we continue to see some recurring safety issues in our accident investigations, highlighting the need for better worker protections. Below are a few recent examples.

• On June 10, 2017, Long Island Rail Road train 7623 approached a five-member roadway crew working on another track at the interlocking in Queens Village, New York. The foreman and three workers were inspecting and making minor repairs, and a fifth roadway worker, a lookout, was clear of the tracks, keeping pace. The lookout sounded a handheld horn, yelled at the others, and raised a disc that told the locomotive engineer to sound the train’s horn, which he did. Unfortunately, the foreman still stepped into the path of the train and was killed. The probable cause of the accident was the decision to use a train approach warning (TAW) system to protect the roadway workers on active tracks.
• On January 17, 2017, a westbound BNSF Railway train, traveling at 35 mph, struck and killed two roadway workers, including the watchman/lookout, in Edgemont, South Dakota. The roadway work group had been cleaning snow and ice from the track switch on the main track to prepare to move a train that was to have its air brake system tested. The crew of the striking train sounded the horn and bell and applied emergency braking; however, there was no response from the roadway work group. The probable cause of this accident was the BNSF Railway roadway work group’s improper use of a TAW to provide on-track safety.
• In several accidents, separating cars carrying hazardous materials from cars carrying crew members has been an issue, as has been the placement of DOT-111 tank cars in trains with other cars carrying flammable liquids, as I’ll describe in more detail below.

Roadway Workers

To better protect roadway workers (those who maintain the track), the Federal Railroad Administration (FRA) implemented Roadway Worker Protection Regulations in 1997. However, since then, more than 50 roadway workers have been killed on the job. Meanwhile, the Federal Transit Administration (FTA) has yet to establish any specific regulations regarding roadway worker protection.

Many of the accidents we’ve investigated have also involved train approach warning systems, which are vulnerable to human errors like miscalculating site distance and generally underestimating the time needed for workers to clear tracks. We have long been concerned with the risks of using this method as the primary form of worker protection, especially because it lacks safety redundancy. Trains travel at deceptively high speeds, and without proper warning, workers may not have enough time to react. Methods of on-track safety that keep trains and other equipment away from workers provide a higher level of protection than TAW systems, which require workers to clear the tracks prior to the arrival of trains and equipment.

Another recurrent issue that we see in our investigations involves training and scheduling practices. Industry needs to ensure that job briefings are done correctly and that procedures are in place to audit those briefings. Additionally, watchmen/lookouts should receive proper training and have the required equipment. Railroads and transit agencies must develop work schedules and limitations based on science to prevent fatigued workers from being eligible to work overtime.

Operations and Mechanical Crews

Like roadway workers, operations crews and mechanical workers have also been killed in preventable accidents. One issue requiring attention is spacing between train crews and rail cars carrying hazardous materials. Although the Pipeline and Hazardous Materials Administration (PHMSA) requires buffer cars between train crews and hazardous materials, the agency has also issued a regulatory interpretation that provides for a much shorter—and less safe—distance between hazardous materials and train crews. We believe PHMSA needs to withdraw its regulatory interpretation so railroads will be required to implement a minimum of five cars as a buffer between train crews and highly hazardous flammable material, at least until PHMSA determines the appropriate separation distance to keep train crews safe.

The Role of Regulators

Because so much in railroad safety is driven by the regulators—the FRA, the FTA, and PHMSA—they are in the best position to make change. Regulators should act expeditiously on our recommendations to establish adequate roadway worker and operations crew protections. Addressing these issues will help to ensure more preventable worker deaths are avoided.

The Role of Industry

Meanwhile, it isn’t necessary for industry to wait to protect workers. Improving training for watchmen/lookouts, for example, and more comprehensive briefings will help prevent accidents. Individual railroad workers, whether roadway workers, mechanical employees, or train crews, can learn more by reviewing NTSB railroad accident reports.

Learn More

Improve Rail Worker Safety

Long Island Rail Road Roadway Worker Fatality
Queens Village, NY | June 2017

BNSF Railway Roadway Worker Fatalities
Edgemont, SD | January 2017

Using Technology to Protect Maintenance-of-Way Employees, Amtrak/Backhoe Collision
Chester, PA | April 2016

Placement of DOT-111 Tank Cars in High-Hazard Flammable Trains and the Use of Buffer Cars for the Protection of Train Crews | December 2020

RAIL SAFETY WEEK 2021

By Member Tom Chapman

Each year, Operation Lifesaver, Inc., spearheads Rail Safety Week. For 2021, Rail Safety Week runs from September 20 through 26. Operation Lifesaver and its safety partners across North America, including the NTSB, use this annual event to educate and empower the public to make safe decisions around trains and tracks and to raise awareness of the need for rail safety education.

Federal Railroad Administration (FRA) data show there were 756 total fatalities on US railroads in 2020. Most of these deaths occurred in highway–rail grade crossing and trespassing incidents. Public awareness and outreach efforts are important because, tragically, hundreds of people are fatally struck by trains in preventable collisions.

I have an especially strong interest in rail safety because, in the early 1950s, my grandfather was struck and killed in a highway–rail grade crossing crash. My grandfather was a volunteer firefighter. He and a colleague were on a call when the collision occurred. The tragedy had a devastating impact on my mother and her family. My mother was a high school student at the time, and the loss of her father changed the course of her life.

At a highway–rail grade crossing, it is our responsibility, as road users, to stop for train traffic. Trains have the right of way and will pass through the crossing without stopping for road traffic. There are two types of grade crossings. At passive crossings, signage will warn road users to be vigilant when crossing tracks and to look for oncoming trains. In more populated areas, you may be more likely to encounter active crossings, which are typically equipped with flashing lights, audible alarms, and automatic gates that warn of an approaching train. When warnings are activated at a crossing, the appropriate and safe action is to stop and wait. Trains are faster than they seem, and they don’t stop on a dime. The average freight train traveling at 55 mph can take a mile or more to stop.

So, what should you do if your vehicle becomes stuck on the tracks at a grade crossing? First, get out of your car. Then, call the number on the Emergency Notification System (ENS) sign posted near the crossing. These blue-and-white signs include a number to call and a US Department of Transportation crossing identification number. If you cannot find the sign, simply call 911. Additional information is included in this brief video produced by Operation Lifesaver. Also, the FRA developed its Crossing Locator App to help you find and call the ENS in case of an emergency or if you have a safety concern about a specific highway–rail grade crossing.

Too often, those who are struck and killed by trains near or on the tracks could have avoided putting their lives in such perilous danger. According to the FRA, more than 400 trespass fatalities occur each year, and the vast majority of them are preventable. An especially tragic example is highlighted in our investigation of a 2014 trespassing accident that involved a film crew near Jesup, Georgia, that was filming on a rail bridge without authorization when a freight train passed. One crewmember was killed, and six others were injured as a result of this preventable accident.

Whether you are taking a shortcut by crossing railroad tracks, or jogging, taking pictures (selfies included), fishing, or riding a recreational off-road vehicle, on or around tracks, you put yourself in imminent danger.

Remember, trains are faster and quieter than you think. They can’t stop quickly. They can’t swerve. They are enormously powerful machines and taking a chance on a collision with a train is risky business.

During this year’s Rail Safety Week, all of us at the NTSB join our friends at Operation Lifesaver in their mission to save lives around railroad tracks and trains. Here’s how you can do your part.

• Know the signs.
• Make good decisions.
• Talk to your loved ones about rail safety.

Together, we can STOP track tragedies. See tracks? Think train.

Fostering Teen Driver Safety Through Policy, Advocacy and Technology

By Bryan Delaney, NTSB Safety Advocate

Motor vehicle crashes continue to be a leading cause of death for American teens. As new teen drivers are tossed the keys to their first car, it’s important for peers, parents, guardians, and other influential individuals to encourage safe driving habits that will last a lifetime. These habits can be a matter of life and death for a novice driver.  The NTSB recognizes the importance of teen driver safety and has issued numerous recommendations to promote safe driving behaviors for these vulnerable road users.

Policy Changes and Advocacy

Over the years, our advocacy efforts to promote youth traffic safety have been unwavering, with a particular focus on our recommendations to states to implement comprehensive graduated driver license (GDL) laws that foster a safe learning and driving experience for novice road users. The NTSB has advocated for strengthening these laws, including promoting nighttime driving restrictions, passenger restrictions, hours-of-driving-experience requirements, seat belt use requirements, and distraction prevention (cell phone and passenger restrictions) to prevent teen-driver-related crashes. The NTSB recommends a three-stage GDL law that proceeds through the following:

• A supervised learning period in which an adult driver at least 21 years old can supervise the teen driver and instill good driving habits. According to the AAA Foundation for Traffic Safety, a teen driver’s risk of death decreases 62 percent per mile driven when a passenger aged 35 or older is in the vehicle.
• An intermediate stage with driving limitations to avoid high-risk driving scenarios (driving at night and driving with passengers). Teen drivers within the intermediate stage, unless accompanied by a supervising adult driver who is at least 21 years old, must refrain from carrying more than one passenger under the age of 20 until they receive full license privileges. According to AAA, a teen driver’s risk of death doubles when carrying two passengers younger than 21 and quadruples when carrying three or more passengers.
• Full license privileges.

If your state does not have a comprehensive GDL law, parents, guardians, and peers can still encourage these typical GDL requirements.

Technology Advances

Whether you’re a teen driver or a seasoned driver, mistakes happen; however, when it comes to driving, our mistakes shouldn’t have deadly consequences. The NTSB has long recommended and advocated for vehicle safety technologies that can assist drivers. We also believe that vehicle safety technology should be available as standard equipment in all vehicles, for all drivers.  Equipping teens with a safe vehicle that includes advanced driver assistance technology can reduce the risks of—and even prevent—crashes. In fact, a new Insurance Institute for Highway Safety study found that equipping your teen driver with a vehicle with crash-avoidance and teen driver safety technologies can prevent or mitigate up to three-quarters of fatal crashes involving teens.

Teens are one of our most vulnerable driving populations, and it’s important that we instill safe driving habits and behaviors in them. Parents, guardians, and peers can have conversations with new drivers about avoiding distracted and impaired driving, buckling up as soon as they get into the vehicle, and follow the rules established within a GDL law, creating a positive example for novice drivers and fostering a safe environment for growth and learning.

As Teen Driver Safety Awareness Week approaches next month, we encourage our readers to stay alert for upcoming events and campaigns focused on teen drivers and the strategies for keeping young people safe behind the wheel. But you don’t have to wait until then to support teen driver safety; you can be an outspoken advocate to the teen drivers in your life today.

Learn More:

• NTSB Most Wanted List: Require Collision-Avoidance and Connected-Vehicle Technologies on all Vehicles (NTSB.gov)
• National Teen Driver Safety Week (Traffic Safety Marketing)
• Teen Driver Risk in Relation to Age and Number of Passengers (AAA Foundation)
• Teen Driver Crashes Potentially Preventable by Crash Avoidance Features and Teen-Driver-Specific Safety Technologies (Insurance Institute for Highway Safety)
• Safe Vehicles for Teens (Insurance Institute for Highway Safety and Consumer Reports)