Recommendations Spotlight Archive

​​​​​​​​​​​​​​​​​​​​​​​​​​​Recommendations That Got Results​

​​​​Each month, we shine the spotlight on a few recommendations that have been successfully implemented (closed acceptable action) and are helping to improve safety. These recommendations span all modes of transportation: 

We urge recommendation recipients to keep us informed of their progress toward implementing recommendations. 


​Improving the Chance of Firefighter Survival in Helicopter Crashes

Like many NTSB investigations, it isn't necessarily one significant hazard or unsafe practice that reduces a victim’s chances of surviving a transportation crash, but many small ones. And, sometimes, it takes the NTSB's unwavering persistence over many years for these small safety improvements to occur.

Last month, the NTSB closed the final recommendation from a 2008 crash involving a Sikorsky S-61N helicopter, which impacted trees and terrain after departing a helispot (a location near a fire where it is safe for helicopters to land and take off) near Weaverville, Calif., that killed the pilot, a crewmember, and seven firefighters and seriously injured the co-pilot and three firefighters. The NTSB issued 10 safety recommendations following this crash; the final one to close improves firefighters' survivability after a helicopter crash. ​

In the Weaverville crash, the firefighter passengers on the accident helicopter were wearing flame-resistant gloves, as required by U.S. Forest Service policy at the time of the accident. However, the gloves were made of a rigid medium-weight leather that hindered the firefighters' ability to quickly unbuckle their seat restraints and open emergency exits after the helicopter crashed.

To address this issue, NTSB recommended (A-10-164) that the Forest Service revise its policies to ensure the gloves firefighting personnel wear during helicopter transport operations are compatible with passenger restraints and opening emergency exits.

In 2023, the Forest Service had implemented the following changes to its policies and guidance:

  • ​All occupants of helicopters under contract with the U.S. Forest Service must wear fire-resistant or leather gloves that fit snugly to provide maximum finger dexterity.
  • Pre-flight briefing guidance and checklists cover seatbelt operation, and glove fit and dexterity. 
  • All helicopters operated under contract to the U.S. Forest Service must be equipped with quick-release buckles, which are easier to operate with gloves than rotary-style buckles like those installed on the accident helicopter.

​The U.S. Forest Service's actions to ensure that seatbelt operation and glove fit and dexterity are discussed and checked before flights and that all contracted helicopters are equipped with quick-release buckles exceed the intent of Safety Recommendation A-10-164, which was classified Closed—Exceeds Recommended Action in February 2024.   ​

​​​Embraer, FAA Address Potential Cause of Several Runway Excursions

​​Between 2011 and 2013, the NTSB investigated and participated in foreign-led investigations of several runway excursions involving Embraer EMB-145 airplanes that unexpectedly veered off the runway during landing due to uncommanded steering anomalies.

During our investigations, we discovered Embraer pilots were using binder brackets to clip their open navigation chart binders on the Embraer-installed chart holder, which is designed to hold individual charts and located directly above the steering tiller.

When the binder, about 2 inches thick and weighing several pounds, dislodged from the (unauthorized) bracket, it would strike the tiller, engage the steering system, and cause the plane to veer off the pilot’s intended landing path.

The NTSB recommended (A-17-3) Embraer inform its operators and pilots not to clip binders to the chart holder due to the potentially hazardous condition the act poses. We also recommended (A-17-5) the FAA reinforce Embraer’s outreach by issuing a safety alert to Embraer pilots and operators.

Those communications were completed, and the NTSB recently closed its recommendations to Embraer and the FAA and classified them as acceptable.  

FAA Improves Airliner Design Standard to Prevent Recurrence of Second Deadliest Crash in US History

American Airlines Flight 587 crashed into a New York City neighborhood about a month after the Sept.11, 2001, terrorist attacks. The accident killed 260 people on the airplane, and 5 people on the ground; it is the seco​​​nd deadliest airplane crash in the United States. The crash occurred after the pilot made rapid, inappropriate, full-rudder deflections, leading to the plane's tail ripping off midair. Following our investigation, we recommended (A-04-56) that the FAA revise certification standards to ensure the safe handling of airliners in the yaw axis throughout the various phases of flight, including rudder-pedal sensitivity limits. Finishing an almost 20-year effort, on Nov. 22, 2022, the FAA published the final rule, “Yaw Maneuver Conditions—Rudder Reversals,” requiring airliners to be designed to withstand the loads caused by rapid reversals of the rudder pedals, addressing the situation that caused the American 587 crash. 

​ ​ ​​FAA Requires Sturdier Oil Gaskets After Several Planes Crash Due to Engine Oil Starvation

The NTSB’s investigation of several reciprocating-engine plane crashes found that their engines lost power during flight due to oil starvation caused by an oil filter gasket failure. In response to our recommendation (A-20-39) to address safety concerns with fiber gaskets, the FAA issued an airworthiness directive (AD) requiring owners to replace the fiber gaskets with sturdier copper gaskets before accumulating 50 flight hours or at the next scheduled oil change. The directive also prohibits any future use of the fiber gaskets. The FAA estimated that about 6,300 registered aircraft are subject to its directive. The fix costs about $246.50 per aircraft, including the $34 replacement gasket.​​

FAA Requires Current Medical Certificates for Commercial Hot Air Ballon Pilots

The NTSB recommended (A-17-34) that the FAA require commercial balloon pilots to have a current FAA medical certificate following a July 2016 hot air balloon accident in Lockhart, Texas, which had the greatest number of commercial aviation fatalities since the 2009 Colgan Airlines accident near Buffalo. In Lockhart, the pilot made several errors, such as taking off in poor ground visibility and continuing into foggy areas where the balloon struck a high-voltage power line. The pilot used various drugs and had a medical history of conditions that should have disqualified him, including conditions likely to affect decision-making. At the time of the accident, balloon pilots were not subject to FAA medical fitness requirements. Following our recommendation, the FAA adopted a final rule requiring commercial hot-air balloon pilots to hold medical certificates when flying paying passengers, except when the pilot is conducting flight training in a balloon. The rule mandates a second-class medical certificate, the same standard required for other commercial pilots.    


​Safety Standard Update Aims to Prevent Natural-Gas-Fueled Explosions

In 2018, explosions from undetected natural gas leaks occurred at three Dallas homes on the same block, one day after the next. While the gas distribution company tested for underground gas leaks at the homes, the instruments failed to detect issues because of wet soil conditions. When the ground is saturated, gas may not vent as expected, leading to false-negative results during routine tests to detect the presence of gas.

Following the NTSB's investigation of the natural-gas-fueled explosions, we issued several safety recommendations, including one to the Gas Piping Technology Committee (GPTC), which writes consensus guidelines to improve the safety of gas transmission, distribution, and gathering piping systems.

Recently, the NTSB closed our recommendation to the GPTC as an acceptable action following the committee's publication of additional guidance that provides steps gas distribution operators can take to thoroughly investigate and respond safely to leaks in wet weather conditions. Specifically, the GPTC added that operators should consider special one-time surveys where gas migration and the ability to quickly identify a suspected leak's location is affected by weather-related conditions, such as water-saturated ground.

The additional guidance also stresses the importance of assessing all potential migration paths, investigation tools, methods, and considerations when the ground is water saturated. If buildings are in the suspected area of migration, the guidance advises operators to follow emergency response procedures, including ventilation or evacuation and isolating the gas supply to the area until conditions improve.

The GPTC adheres to the American National Standard Institute's rigorous standard development processes and directly improves safety among gas distribution operators nationwide.


PG&E Completes Integrity Tests on Nearly 2,000 Miles of Natural Gas Pipeline to Prevent Another San Bruno Natural Gas Explosion

A Pacific Gas and Electric Company (PG&E) natural gas pipeline ruptured, triggering an eruption that leveled a San Bruno neighborhood on Sept. 9, 2010. The explosion and fire killed 8 people, injured 58, and destroyed 38 homes. Following our investigation, we recommended (P-10-4​) that PG&E determine its pipelines' maximum allowable operating pressure. The NTSB recently classified the recommendation as Closed-Acceptable Action because PG&E addressed it by completing strength-testing or verifying strength-test records for over 1,850 miles of pipeline. 

Energy Company Fixes Policy and Procedural Weaknesses that Led to Three Dallas Home Explosions

In February 2018, three Dallas, Texas, homes on the same block exploded one day after another, killing one person and injuring several others. The NTSB’s investigation found that the energy company’s leak detection methods and response policies and procedures for natural gas explosions and fires were insufficient. We recommended (P-21-11) that the energy company, Atmos Energy, address those weaknesses. The company made the following changes: 

  • ​​Leak investigation methods that are reliable in wet weather
  • Leak investigation procedures that assess all viable gas migration paths
  • Criteria for when to shut down or isolate gas distribution systems and pressure test main and service lines
  • An alternate safe response, such as evacuation when reliable leak investigations are impossible due to wet weather or other circumstances


​Rail Association Calls on Members to Hold Employee Safety Briefings on Lessons Identified from Tragic Collision​

​The NTSB issues safety recommendations to those entities that can take action to prevent the recurrence of similar transportation accidents and incidents. A fast and effective method of reaching our affected audiences with a safety message is through their trade associations and professional societies.

In 2021, the NTSB issued a recommendation to the American Short Line and Regional Railroad Association (ASLRRA) asking it to share with its members the circumstances of a 2021 collision that killed a 19-year-old train conductor, who was riding on the rear platform of a train slowly backing down the tracks (also known as shoving).

When the conductor’s rail car entered a highway-railroad grade crossing, an 18-wheeler struck it, pinning the conductor between the train and the truck. The grade crossing had warning signs but no mechanical gates to prevent crossing. Our investigation found that the truck driver did not heed the warning signs and failed to stop when entering the grade crossing.

In response to our recommendation (R-23-021​), ASLRRA asked its members in its newsletter to read the details of the NTSB investigation report, review their procedures related to shoving movements, and communicate them to their employees in an upcoming safety briefing. In the news article, the association also highlighted to its members: “The NTSB recommends that railroads require ground protection at highway-railroad grade crossings equipped only with flashing lights or passive warning devices.” 

 The NTSB recently closed the ASLRRA recommendation and classified the association's publication of an article in its member newsletter as acceptable.

​​CSX Rai​lroad Trains Emergency Responders on Hidden Hazards to Reduce Risk 

In a 2017 train derailment in Hyndman, Pa., involving several rail cars containing hazardous materials, CSX railroad's emergency responders put their lives at risk by working perilously close to the derailment scene to hasten stabilization. 

NTSB's accident investigation discovered that emergency responders were unaware of a potentially hazardous bulge developing in the tank because the rail car's protective layer, known as a jacket, obscured the surface of the tank car's shell. The jacket is an eighth of an inch thick steel skin that wraps around the tank shell. 

In response to NTSB's safety recommendation (R-20-24), CSX revised its emergency responder training and outreach programs to incorporate lessons learned about jacketed tank cars from NTSB's investigation of the CSX train derailment. By 2025, rail tank cars carrying crude oil and ethanol will be required to be jacketed.

CSX also built a full-size model train called a Responder Incident Training (RIT) train to give emergency first responders hands-on experience with the safety features of jacketed tank cars. 

After NTSB staff attended CSX's in-person and virtual training, the NTSB classified CSX's response to our safety recommendation as acceptable. While the in-person training is only available on CSX properties, the virtual Emergency Response to Rail Incidents (ERRI) training is free to the public on the Transportation Community Awareness Emergency Response's website.

Emergency response is an aspect the NTSB commonly assesses during its accident investigations. Recently, NTSB's investigation of the Feb. 3, 2023, Norfolk Southern train derailment and hazardous materials release in East Palestine, Ohio​, again highlighted the importance of effective emergency response.    ​

N​​YC Mass Transit Creates a System of Continuous Safety Improvement

Following the NTSB’s investigation of a series of accidents on New York City’s commuter and inner-city mass transit system, we issued several recommendations (R-14-66 thru -68) to the Metropolitan Transportation Authority (MTA) to identify and mitigate hazards across the city’s entire transit system. In response, the MTA created a safety council comprised of safety officers from each of the MTA’s railroads that meet each week to review safety data, trends, hazards, and mitigations. The council shares that information monthly with the MTA railroad presidents and board members. The forum enables the MTA to systematically evaluate deficiencies identified on one MTA property and apply the hazard mitigations to the others. We recently classified our recommendations to the MTA as Closed-Acceptable Action.   ​

WMATA Improves Operator Emergency Shutdown Training, Implements Recurring Ventilation System Testing

Our 2015 investigation of a WMATA Yellow line train that encountered heavy smoke while leaving the L’Enfant Plaza station heading toward the Potomac River Bridge identified issues with the train operator not correctly shutting the railcar ventilation system down to minimize smoke being pulled into an occupied WMATA car. We recommended WMATA train operators on emergency shutdown procedures and regularly test railcar ventilation systems. WMATA revised its operator training to ensure that operators can take needed emergency actions and implemented recurring testing of its railcar ventilation systems. (Safety Recommendations R-16-19 and R-16-20.)

Coast Guard Improves Vessel Traffic System’s Role in Safely Managing Marine Traffic

In 2016, the NTSB completed a study of the Coast Guard’s Vessel Traffic System (VTS), a marine traffic monitoring system established by harbor or port authorities, similar to air traffic control for aircraft. We issued 17 recommendations to the Coast Guard to address safety issues found in the investigation. The Coast Guard recently reported to us that it has taken several actions in response, including revising its VTS National Standards for Operating Instruction. As a result, we classified 9 of our 17 recommendations Closed-Acceptable Action. (M-16-6​)

​​NHTSA Takes Important Step Toward Standardizing Impaired-Driver Toxicology Testing Nationwide

On New Year’s Day 2021, a 28-year-old drug-impaired driver swerved his sport utility vehicle (SUV) into oncoming traffic on a two-way road near Avenal, Calif., and collided head-on with a pick-up truck carrying an adult driver and seven children. The SUV driver and all eight pickup truck occupants died. ​​

In this highway investigation, the NTSB found that the driver’s blood alcohol concentration was more than double California's legal limit. Unfortunately, the NTSB could not determine if other drugs contributed to the driver's impairment because the Fresno County medical examiner's postmortem toxicology testing of the driver's blood did not screen for other common drugs. The NTSB later detected cannabis in the driver's blood when conducting its post-crash toxicology tests. 

For alcohol impairment, years of experience and a robust data-gathering process have reliably established detectable levels of blood alcohol associated with impairment. However, for other widely available drugs, both legal and illicit, the data available are insufficient to develop enforceable impairment markers and effective countermeasures.

We could improve the information on the prevalence of impairing drug use by drivers if testing protocols were standardized. Like many other states, California had no uniform standard for drug toxicology testing at the time of the 2021 Avenal crash. 

Following our investigation, the NTSB issued a safety recommendation (H-22​​-33)​​ to the National Highway Traffic Safety Administration (NHTSA) to disseminate a nationally recognized drug toxicology testing standard to state officials.

The NTSB recently closed its recommendation to NHTSA as an acceptable action when NHTSA distributed the National Safety Council's "Recommendations for Toxicological Investigations of Drug-Impaired Driving and Motor Vehicle Fatalities through the Regional Toxicology Liaison Program" to all state officials.  ​​​

​ ​​​NTSB’s School Bus Stop-Arm Camera Recommendation Takes Hold in the States

NTSB’s call for states to permit school bus stop-arm cameras is steadily taking hold across the country, with 25 states enacting laws to prevent illegal school bus passings that have reached an epidemic level, putting student safety at risk. 

Florida, Michigan, and Delaware are the most recent states to adopt NTSB’s stop-arm camera safety recommendation, which the agency issued in 2020 to 28 states and the District of Columbia. The agency made the recommendation (H-20-12) following its investigation of a 2018 Rochester, Indiana crash, where three children were struck and killed and another severely injured when crossing a two-lane highway to board their school bus.

The National Association of State Directors of Pupil Transportation Services estimates that over 41 million vehicles illegally passed school buses in a 180-day school year. Stop-arm cameras record the license plates of vehicles illegally passing school buses, enabling police to issue citations to violators, an effective deterrent to dangerous driver behavior.

Read NTSB’s testimony in support of stop-arm camera legislation before Oregon’s House Judiciary Committee. 



Texas Adopts NTSB’s Recommendation to Use Variable Speed Limits to Prevent Highway Crashes

​Following the NTSB’s recommendation that Texas use variable speed limit signs to reduce crashes occurring on its highways during inclement weather, the state recently authorized the Texas Transportation Commission to use them on its roads.

Variable speed limit signs, unlike static ones, can be adjusted when changing road conditions require safer speed limits to reduce the risk of highway crashes. 

The NTSB first asked Texas (H-05-20) to install variable speed limit signs following the agency’s investigation of a 2003 crash near Hewitt, Texas, where a motorcoach bus skidded during braking, crossed over a grassy median, entered the southbound lane, and collided with an SUV. The crash occurred during inclement weather with reduced visibility due to fog, haze, and heavy rain. Seven people died, and several other people were injured in the crash.

In 2023, the NTSB asked Texas again (H-23-3​​) to use variable speed limit signs following the agency’s investigation of a 2021 Fort Worth crash where six people died in a multivehicle pileup on an icy highway with a posted speed of 75 miles per hour. 

U​pdated April 24, 2024​