Category Archives: Uncategorized

Remembering Air Florida Flight 90 and the Progress Towards Eliminating Airline Icing Accidents

By Jeff Marcus, Chief, NTSB Safety Recommendations Division

Forty years ago, on Jan. 13, 1982, a Boeing 737 jetliner crashed into Washington, DC’s 14th Street Bridge and plunged into the freezing Potomac River after departing National Airport during a snowstorm. The crash killed 73 of the 79 people aboard the airplane and 4 people in cars on the bridge; 4 others on the bridge were injured. A total of five passengers and a flight attendant escaped the airplane into the freezing, ice-filled Potomac River and clung to wreckage.

About 20 minutes after the crash, a National Park Service helicopter arrived. Showing remarkable flying skills, the pilot and paramedic worked so close to the water that at times the helicopter’s skids dipped beneath the surface. They managed to pull four of the survivors to shore. As a fifth survivor lost her grip on the helicopter’s lifeline, Lenny Skutnik—one of hundreds of bystanders—dove into the icy water and brought her to the riverbank.

(A U.S. Park Police helicopter pulls two people from the wreckage of an Air Florida jetliner that crashed into the Potomac River when it hit a bridge after taking off from National Airport in Washington, D.C., on Jan. 13, 1982. Photo by Charles Pereira, Associated Press)

A sixth survivor of the impact had taken the lifeline and flotation rings from the helicopter and passed them to others. When the helicopter returned for him, he was gone. The 14th Street Bridge is today named in honor of that passenger, Arland D. Williams.

NTSB investigators found that after traveling almost half a mile farther down the runway than was typical for a normal takeoff, the airplane lifted off and attained a maximum altitude of only about 350 feet before crashing into the bridge, which was less than a mile from the end of the runway. While the airplane was on its takeoff roll, the first officer remarked several times, “that don’t seem right, does it? Ah, that’s not right. That don’t seem right.” The captain did not respond.

The NTSB’s investigation identified numerous errors related to safely flying in snowy and icy conditions.

  • Though the outside temperature was well below freezing and snow was falling, the crew did not activate the engine anti-ice system that prevents sensors in the engines from freezing and giving incorrect engine power readings. Although the pilots set the engines to the correct power setting, the NTSB’s analysis showed the engines were actually operating with substantially less power than was needed.
  • After leaving the gate, the aircraft waited in a taxi line with many other aircraft for 49 minutes before reaching the takeoff runway. The pilot decided not to return to the gate for reapplication of deicing, fearing that the flight’s departure would be even further delayed. More snow and ice accumulated on the wings during that period.
  • While waiting in line to take off, the pilots decided to maneuver closely behind a DC‑9 that was taxiing just ahead of them, mistakenly believing that the heat from the DC-9’s engines would melt the snow and ice that had accumulated on flight 90’s wings. This action, which went specifically against flight-manual recommendations for an icing situation, contributed to the icing on the Air Florida jet. The exhaust gases from the DC-9 turned the snow into a slush mixture that froze on the wings and the engine.
  •  Although the crew was aware of the ice and snow on the wings, they decided to take off.

Air Florida flight 90 was just one of numerous airframe-icing-related crashes we’ve investigated. Between 1982 and 1997, we investigated eight fatal accidents of aircraft flown by professional flight crews that encountered icing conditions. Other professionally crewed flights were among the numerous icing accidents we investigated through April 2011, when the final report on such an accident was issued. These crashes killed 265 people. Similar problems were found by the Canadian Transportation Safety Board where two accidents in 1985 and 1989 killed 280 passengers and crew.

As a result of these accidents, we’ve issued several recommendations covering a variety of topics, including the following:

  • Deicing fluid properties
  • The number of minutes after which a plane can safety take off after being deiced
  • Airport congestion and the time needed for air traffic control clearance, which can delay takeoff beyond when deicing fluid is effective
  • The importance of deicing engine instruments that are used to set the proper engine power
  • Prolonged autopilot use in icing conditions can mask developing problems with controllability until it is too late to avoid a crash
  • Icing on swept wing aircraft (including most airliners) can cause an airplane to pitch up uncontrollably, leading to a stall
  • Small amounts of ice on an airplane wing (comparable to the roughness of sandpaper) disrupt airflow and reduce the airplane wing’s ability to hold up the airplane
  • FAA certification standard revisions for airplanes approved to fly in icing conditions
  • Increasing stall speed in icing conditions

Because the NTSB identified airframe icing as a significant threat to aviation safety, it was on our Most Wanted List of Transportation Safety Improvements for 14 years.

After researching how ice forms on airplane wings in flight, and how that ice affects airplane performance, the FAA revised the standards for airplanes certified for flight in icing conditions. Pilot training and flight procedures were improved, and more attention was paid to minimizing the time between deicing and taking off.

Although the NTSB still investigates aviation accidents involving icing, the numbers are down drastically. We have not investigated a fatal icing-related crash involving a professional flight crew since the February 16, 2005, crash of a Cessna Citation 560 in Pueblo, Colorado.

At the NTSB, we draw knowledge from tragedy to improve the safety of all. The knowledge gained from our investigations of icing accidents, such as Air Florida flight 90, identified the actions needed to improve the safety of everyone who flies.

Let’s Stop Going the Wrong Way

By Robert Molloy, PhD, Director, NTSB Office of Highway Safety

If you’re driving down a divided highway and see headlights coming right at you, or hear screeching tires and see cars and trucks swerving to get out of your way, it’s probably an indication you’re heading in the wrong direction. Another indicator may be the large signs that read “Wrong Way” and “Do Not Enter.” The signs are always there, yet, unfortunately, they can go unnoticed, with catastrophic results.

“Do Not Enter” and “Wrong Way” signs posted on an exit ramp (Source: New York State DOT)

The NTSB has a long history of investigating collisions involving vehicles traveling the wrong way on high-speed divided highways. Wrong-way crashes occur relatively infrequently, but they are much more likely to result in fatal and serious injuries than any other type of highway crash.

In December 2012, we released a special investigation report looking at the causal factors involved in wrong-way crashes. In that report, we issued 16 safety recommendations aimed at prevention, many of which are still open, awaiting action by highway safety regulatory agencies, automotive industry groups, and states.

As we strive toward safety, we must look at what the trends and data are telling us. Are we heading in the right direction regarding wrong-way crashes? Today, the AAA Foundation for Traffic Safety released a research brief examining fatal wrong-way crashes. It contained alarming statistics that should be a flashing “Wrong Way” warning sign to all of us. The trendline for these crashes is clearly moving in the wrong direction.

The AAA’s analysis shows that, between 2010 and 2018, there were 3,885 deaths resulting from wrong-way driving crashes—an average of 430 deaths per year. This is a 19-percent increase over the 360 fatalities per year found in our analysis of 2004 to 2009 crash data. In total, we have lost a staggering 6,024 precious lives in wrong-way crashes in just 15 years—an unacceptable loss of life, especially when these types of crashes are preventable.

Like our earlier report, AAA’s research found that alcohol impairment plays a large role in wrong‑way crashes. Over 60 percent of wrong-way drivers in fatal crashes are impaired. In May 2013, we published Reaching Zero: Actions to Eliminate Alcohol-Impaired Driving, which includes a comprehensive list of safety recommendations to help eliminate alcohol‑impaired driving. Specific prevention strategies needed to reduce wrong-way crashes include the following:

  • Increase high-visibility impaired-driving enforcement, including sobriety checkpoints and saturation patrols, in areas where wrong-way driving movements are most prevalent.
  • Accelerate the development of in-vehicle alcohol-detection technologies.
  • Require the use of alcohol ignition interlock devices for all individuals convicted of driving-while-impaired offenses.
  • Reduce the per-se blood alcohol concentration (BAC) limit to 0.05 or lower for all drivers. Lowering the BAC has been shown to provide a broad deterrent effect.

AAA research also found that older drivers are more at risk of wrong-way driving than their younger counterparts. The NTSB has open recommendations to the states calling on them to develop a comprehensive highway safety program for older drivers that incorporates, at a minimum, the elements of the National Highway Traffic Safety Administration’s Highway Safety Program Guideline No. 13—Older Driver Safety. A successful program includes driver licensing and medical review of at-risk drivers, education for the medical and law enforcement community, and improved roadway design for older driver safety.

The NTSB, AAA, and others have developed a roadmap for preventing wrong-way crashes. It’s about time we do a U-turn and start heading in the right direction. I applaud the AAA Foundation for Traffic Safety for this recent research. We can’t ignore the flashing warning sign that we are going the wrong way toward preventing deadly wrong-way crashes on our highways.

Resilience in a Time of Crisis: NTSB Employees Shine Despite Uncertainty

By Chairman Robert Sumwalt

It’s been quite a year! This time last year, none of us had heard of COVID-19. It’s still difficult to process the profound effect that this crisis has had, and continues to have, on people’s lives and on society.

At the NTSB, we understand all too well the duality of a crisis: difficult challenges bringing out the best in people. And this year, our people shined during an unpredictable and stressful time. By putting people first in 2020, we were able to grow, stay engaged, and thrive. From our hastily scrambled-together makeshift home offices and virtual board rooms, we managed, nonetheless, to get the job done.

As expected, our employees showed great resilience and agility, adapting to significant operational change in an uncertain and fast-changing landscape. Following the start of our max telework operations in March, NTSB employees found ways to continue delivering our high-quality products from home. Although I’ve always had high expectations of the NTSB workforce, I can honestly say that, considering the challenges we’ve all faced over the past 9 months, NTSB employees have surpassed all expectations.

The creativity and resilience of our employees working in the virtual environment has led to some unexpected efficiencies, too—in both time and resources. Through our employees’ hard work, the agency has been able to catch up on backlogs, follow up on and close several open recommendations, and publish more reports and products than in years past, putting us in a stronger position moving forward.

Since the beginning of March, our investigative staff across each of the transportation modes have completed 1,293 investigations—a 21‑percent increase over the same period last year.

The employees in our Office of Research and Engineering (RE), who support all our investigations by reading out recorders, providing medical expertise, analyzing materials to determine failure modes, and conducting statistical analyses and data requests, completed 760 reports and fulfilled 240 data requests. Within RE, the vehicle recorders investigative staff completed 361 reports, decreasing their backlog by 60 percent. The materials lab staff reduced their backlog to the lowest it’s been in 12 years.

Since the beginning of the year, our Freedom of Information Act backlog decreased by 85 percent, thanks to the hard work of the employees in our records management division. With a backlog now in the double digits, we have the lowest level of open cases in 8 years. These employees are committed to eliminating the backlog entirely.

NTSB Board meetings, which are essentially hearings where the full Board deliberates accident findings, probable cause, and recommendations, are always conducted in open, publicly attended meetings. Thanks to the efforts of many, we successfully conducted seven virtual Board meetings. Although Board meetings have been webcast for years, these virtual meetings have had some of the highest ever attendance by remote viewers. Three of the seven had over 1,000 remote viewers, and one was the highest ever attended by remote viewers, with nearly 2,500 viewers.

Our Administrative Law Judges conducted 10 virtual hearings, with two more scheduled for next week. Meanwhile, the employees in the Office of the Chief Financial Officer worked with outside auditors to obtain the agency’s 18th consecutive clean audit opinion. This involved working in the virtual space to supply auditors with over 300 documents.

The employees of the NTSB Training Center quickly adopted to the virtual environment, offering eight courses that typically would be taught in person at our training center in Ashburn, Virginia. This is in addition to producing over 40 training courses that are typically administered online for NTSB employees.

Our chief data scientist collaborated with the NTSB’s enterprise architect, our various modal offices, and employees in our Office of Safety Recommendations and Communications (SRC) to develop and roll out a new multimodal database known as SAFTI—System for Analysis of Transportation Investigations. Concurrent with this project, NTSB staff developed a new online database search tool known as CAROL—Case Analysis and Reporting Online query tool, which provides the public with advanced search capability when seeking investigative information. SAFTI and CAROL were mandated by Congress and, through the tireless efforts of our employees, the project was completed on time.

There are several other important functions that our employees performed behind the scenes, such as recruiting and onboarding new employees, working to procure contracts, writing legal opinions and providing legal counsel, along with other administrative tasks. Our managing director and her staff, along with other senior agency leaders, run the NTSB’s day-to-day operations. All of these employees are so vital to keeping the wheels of the agency turning, whether it’s through clear skies or through the dark overcast of a pandemic.   

None of this could have been possible without a robust IT network. Many of us, myself included, had never heard of Microsoft Teams or Zoom at the beginning of 2020. Thankfully, all throughout 2019, NTSB’s IT team was busily implementing a highly available, resilient network with state-of-the-art virtual collaboration tools. When the pandemic hit, these IT enhancements allowed us to continue to fulfill our mission, virtually and without delay.

Additionally, employees were able to stay informed and connected during 100 percent max telework thanks to the launch of our internal intranet platform, InsideNTSB. The SRC team deployed the new site at the end of February. It has become a daily hub for communications where employees can find fresh news and event announcements, work resources, and articles spotlighting staff and office achievements. 

Fundamental to accomplishing our mission was the commitment to keep our people safe. We assembled a COVID team consisting of our in-house medical professionals and representatives from other offices, including our managing director’s office, human resources division, and our workplace safety experts. The team was tasked with determining the safest and most appropriate way for us to resume investigative travel, including launching to investigations and investigative follow-up activities. Working in close collaboration, our RE and CIO staff developed a COVID dashboard, which shows the COVID rate in near real time for each county in the country. This information is fed into an extensive risk assessment that we use to determine how to proceed with travel.

All of this is to say how much I appreciate the resilience and commitment of the great employees of the NTSB, including the agency’s leadership team. While faced with a crisis of unimagined proportion, these employees have shown great resolve. It’s our employees that make the NTSB one of the best places to work in the federal government.

I wish all a safe and healthy holiday season, and a very good new year!

Flatten the Curve Beyond COVID-19

By Leah Walton, NTSB Safety Advocate

When I read the extended nationwide maximum telework order, prolonging the order that started on March 17th, I couldn’t help but think about what impact the COVID-19 preventive measures might have on traffic deaths around the country. Surely, we’ll see a drop in vehicle miles traveled, like we did in the last great recession, but will that give us a false sense of security that traffic safety has improved? The truth is, even though fewer people are driving, and we might see a drop in traffic fatalities in 2020 due to social distancing and stay-at-home orders, risky driving behaviors persist. On one hand, I’ve seen reports of drivers using the emptier-than-normal freeways as their personal racetracks, and on the other, I’ve seen reports of significantly lower drunk driving arrests in the month of March.

It’s encouraging to see so many people following state orders to implement social distancing and staying at home—if there are fewer people on the roads, there is less risk for vehicle-related injuries, which keeps people out of hospitals, allowing hospital workers to focus on the influx of coronavirus patients. However, this causes me to wonder: if people can be convinced to stay home to avoid contracting a dangerous and sometimes deadly virus, could they also be convinced to designate a sober driver or drive their vehicle at posted speeds? After all, those are lifesaving behaviors, as well.


As a transportation safety advocate, I know that motor vehicle crashes are a serious threat to public health in the United States. In 2018, 36,560 people were killed in traffic crashes. The Insurance Information Institute estimates that 1,894,000 people were injured in traffic crashes in the same year. According to NHTSA, 94 percent of all serious traffic crashes are the result of human error; or, in other words, they’re caused by a driver’s choices. We should not let the stress of COVID-19 lower our guard on safe driving practices. Remaining vigilant behind the wheel is critical now more than ever with children home from school, often playing outside, riding bikes in the streets. More people are out walking; sometimes in the street to practice social distancing of other pedestrians.


The CDC has been promoting thorough handwashing procedures and the importance of covering a cough and sanitizing surfaces to prevent the spread of COVID-19. But did you know that the CDC also promotes motor vehicle safety behaviors like driving sober, buckling up, and not driving distracted?

We are extremely troubled by the increasing number of deaths and cases across our country related to COVID-19. Doctors, scientists, and public health professionals are all searching for a cure or a vaccine to eliminate this virus as quickly as possible. At the NTSB, we’re incredibly grateful for all those professionals—including those transporting vital supplies around the country. If Americans can choose to stay home to help slow the spread of COVID-19, imagine the impact we could have if everyone chose to make the safest driving choices for ourselves and our fellow road users. We have the power to flatten the curve of traffic deaths by making safe choices every day.

Automated Vehicles and Distraction: Lessons Learned from Mt. View

By Robert Molloy, PhD, Director, NTSB Office of Highway Safety

The National Transportation Safety Board (NTSB) met on February 25 to consider the 2018 collision of a Tesla Model X, operating with partial driving automation, with a damaged crash attenuator in Mountain View, California. The car steered out of its travel lane and into a gore area, where it collided with the damaged highway safety hardware. The driver didn’t notice the errant path the vehicle had taken because he was interacting with a game application on his work phone.

March 23, 2018, crash of a Tesla in Mountain View, California
Northbound view of the crash scene before the Tesla was engulfed in flames. (Source: witness S. Engleman)

It was a tragic event for both the driver and his loved ones, and the tragedy was compounded because the event was utterly preventable. In this crash, the driver behaved as if his partially automated vehicle were self-driving when it wasn’t. The driver’s resulting distraction, tragically, led to his death. But it’s rare that a crash is the result of a single factor. At the NTSB,  we try to identify all the factors contributing to a crash so we can propose multiple methods to prevent a similar crash in the future. The NTSB doesn’t apportion blame or liability; we look for ways to prevent the next occurrence.

In this crash, we identified or reiterated several ways to prevent a similar tragedy:

  • Because drivers using portable electronic devices while driving often crash, we recommended that device manufacturers find a way to lock people out of their devices while they’re driving.
  • Because “Autopilot,” Tesla’s automated vehicle control suite, is only designed for certain conditions, we reiterated our recommendation to disable it when those conditions are not met.
  • Because Tesla’s proxy measure for driver engagement—torque on the steering wheel—was previously found ineffective, we reiterated a recommendation that Tesla find an effective measure of driver engagement.
  • Because this vehicle crashed into objects that it “did not detect, and [were] not designed to detect,” (a crash attenuator) we recommended that the National Highway Traffic Safety Administration (NHTSA) rate collision avoidance systems under its 5-star rating program, incorporating such objects into its assessment.
  • Because we found that misuse of Tesla’s automation was foreseeable, we recommended that NHTSA evaluate Tesla Autopilot-equipped vehicles to determine if the system’s operating limitations, foreseeability of driver misuse, and ability to operate the vehicle outside the intended operational design domain pose an unreasonable risk to safety, and to ensure that Tesla takes corrective action if safety defects are identified.
  • Because the crash attenuator that the Tesla crashed into had not been repaired, and because lane markings were worn in the area of the crash, we made recommendations to state agencies responsible for maintaining highway infrastructure.
  • Because Apple, the driver’s employer, had no distracted driving policy, we recommended that it adopt one.
  • Because many other companies also don’t have such a policy, and because transportation accidents are a leading cause of workplace injury and death, we recommended that the Occupational Safety and Health Administration review and revise its distracted driving initiatives and add new enforcement strategies.
  • Because it is important to have ready access to data that fits defined parameters to assess crashes involving automated vehicle control, we reiterated recommendations to require standardized data reporting, including incidents, crashes, and vehicle miles traveled, with such systems enabled. This recommendation would also allow the NTSB and NHTSA to evaluate real data on the safety of level 2 automation, not just industry claims.

When we investigate a crash, we aren’t looking for a driver, a company, or an agency to blame; we’re looking for all the ways the next crash can be prevented. When prevention is the goal, those drivers, companies, and agencies are often happy to help make the changes needed to ensure safety. We hope all parties will heed the lessons learned from this tragic crash and take the steps we’ve recommended to increase the safety of the traveling public.