Buzz
Today, air travel on commercial airplanes is widely regarded as one of the safest modes of transportation. However, this level of certainty was not always the case in the skies. In fact, the relatively modern safety standards we now rely on were only established due to some urgent and significant changes made throughout the past century of commercial aviation. Tragically, many of these safety advancements were a direct result of horrific crashes and the loss of many lives, which highlighted the urgent need for reform and updates to aviation systems.
This list examines ten major airline accidents and incidents that prompted immediate, pivotal changes in aviation safety. Although these disasters were heart-wrenching for the families and friends of those lost, they served as turning points for the airline industry. These ten tragic events, although devastating, helped shape a future where air travel has become much safer, with substantial improvements that have prevented further disasters.
10. The Grand Canyon Collision of 1956
On the morning of June 30, 1956, two aircraft departed from Los Angeles International Airport. One, a United Airlines Douglas DC-7, was headed for Chicago, while the other, a Trans World Airlines Lockheed L-1049 Super Constellation, was on its way to Kansas City. However, high above the Grand Canyon, the two planes crossed each other's flight paths, leading to a catastrophic mid-air collision. Both aircraft plummeted to the earth, resulting in the tragic deaths of all 128 passengers and crew on board.
The nation was immediately outraged by such a tragic event. However, the federal government responded swiftly, establishing what would become the Federal Aviation Administration (FAA) within less than two years to regulate and monitor aviation safety. Additionally, the government allocated more than $250 million to modernize the national air traffic control system, believing that increased surveillance of flight paths would help prevent future disasters. This heightened oversight was a crucial and welcome change to the growing aviation sector, and it proved effective—for the next three decades.
On August 31, 1986, an Aeromexico DC-9 took off from Los Angeles International Airport when a small private plane entered its airspace. The private aircraft lacked a transponder, and the Aeromexico pilots were completely unaware of the impending danger until the planes collided mid-air. This second tragic collision led to further reforms in aviation. The FAA mandated that small aircraft must use transponders in controlled airspace, and all major airlines installed TCAS collision-avoidance radar systems. These changes have been successful, as no small plane has collided with a commercial airliner in the years since.
9. United Airlines Flight 173
On the crisp, clear afternoon of December 28, 1978, United Airlines Flight 173, a DC-8, was approaching Portland, Oregon, with 181 passengers aboard. During the descent, the crew realized there was an issue with the landing gear, so they decided to enter a holding pattern, circling the airport for over an hour as they tried to resolve the problem. Unfortunately, the prolonged delay led to a fuel shortage. Despite the flight engineer’s attempts to alert the captain to the situation, the captain dismissed his warnings and continued to ignore him, displaying arrogance and poor communication.
As a result, the aircraft initiated its emergency descent far too late and without enough fuel. It was unable to reach the runway and crashed in a Portland suburb as the fuel ran out. While the outcome could have been far worse, with only ten fatalities, the situation could have been avoided if there had been better communication in the cockpit. The incident emphasized the critical importance of teamwork and proper communication between flight crew members.
Appalled by the pilot’s actions during the prolonged holding pattern as he dealt with landing gear issues, United Airlines quickly took action by developing new cockpit training procedures. This led to the introduction of a concept known as Cockpit Resource Management (CRM).
This concept, now standard across all airlines, was revolutionary at the time. It challenged the long-standing belief in the unquestionable authority of the captain and instead emphasized open, equal communication among the entire crew. United Airlines sought to ensure that no flight would ever again be jeopardized by a domineering captain ignoring the input of the rest of the team.
8. Delta Airlines Flight 191
On August 2, 1985, everything seemed typical at Dallas-Fort Worth International Airport as Delta Airlines Flight 191, a Lockheed L-1011 jet, began its approach to land. Thunderstorms had been present in the area throughout the afternoon, and as the plane descended below 1,000 feet, the pilots noted the presence of lightning. Without any warning, a microburst wind shear hit the plane, rapidly shifting the wind and causing the aircraft to lose most of its airspeed in just seconds.
With no knowledge of how to counteract the effects of this wind shear caused by the thunderstorm, the pilots were powerless. The plane rapidly descended and crashed about one mile short of the runway. It landed on a highway, striking and killing one driver in a vehicle. The plane then skidded and crashed into two large water tanks on the edge of the airport. In total, 134 of the 163 people aboard were killed, along with the driver on the highway.
The FAA was deeply alarmed by the sudden, unexplainable cause of the crash. They launched an extensive investigation and, after some time, realized that the stormy weather conditions played a significant role. To better understand this phenomenon, they sought NASA’s expertise. After seven years of meticulous research, they discovered that previously unrecognized wind shear in thunderstorm conditions posed serious risks to aircraft.
In response, the FAA mandated the installation of advanced radar and wind-shear detectors on all commercial airliners. Since the nationwide implementation of this directive in the mid-1990s, only one similar wind shear-related microburst incident has occurred.
7. United Airlines Flight 232
United Airlines Flight 232 began as a routine flight from Denver to Chicago, departing under clear skies on July 19, 1989. However, while cruising over Iowa, the DC-10 unexpectedly experienced total engine failure. The engine located in the tail of the aircraft also severed the hydraulic lines, rendering the jet nearly uncontrollable as it descended rapidly toward the ground.
Captain Alfred Haynes exhibited remarkable courage and skill as he fought to control the struggling jet. He managed to steer the plane toward Sioux City, Iowa, where he attempted an emergency landing. Against all odds, he managed to bring the plane closer to the airport, though the landing was anything but smooth. The crash, which occurred after the runway, claimed the lives of over 100 of the 296 people on board.
After the tragic crash, the National Transportation Safety Board (NTSB) and the FAA investigated the incident to uncover the cause. They quickly determined that a small crack in the tail engine’s fan disk had caused the disaster. This crack had formed during the original manufacturing process of the DC-10’s titanium alloy.
In response, the FAA immediately mandated a complete overhaul of the DC-10’s hydraulic systems. Although the plane was already being phased out by airlines by the late 1980s, this move accelerated its retirement. The Sioux City investigation also led to significant changes in airliner safety protocols: the NTSB and FAA now required fully redundant safety systems in all new commercial aircraft. Furthermore, they implemented stricter inspection procedures for engines, aiming to avoid any future engine failures like the one that caused this crash.
6. US Airways Flight 427
On September 8, 1994, US Airways Flight 427 was approaching Pittsburgh, Pennsylvania, when the Boeing 737 suddenly plummeted from the sky. In mere seconds, the aircraft dropped more than 5,000 feet (1,524 meters) after it unexpectedly rolled to the left. All 132 people aboard were killed in the crash, causing shockwaves throughout the American aviation industry.
Immediately following the crash, US Airways blamed the plane for failing at a critical moment. Boeing, on the other hand, placed the blame on the pilots, attributing the crash to their errors rather than a mechanical fault. The FAA retrieved the black box and began investigating. Eventually, they discovered the cause of the 5,000-foot drop: the jet’s rudder had inexplicably moved into a full-left position during descent, triggering a roll that the pilots could not correct. The mystery remained: was the plane at fault, or did the pilots make a mistake?
After almost five years of exhaustive investigation, the NTSB and FAA concluded that the plane itself was to blame. A malfunctioning valve in the rudder-control system had caused the rudder to reverse and fully deflect to the left. As the plane descended, the pilots desperately pressed the right rudder pedal, but each time they did, the rudder moved further left, forcing the plane into its fatal dive.
Acknowledging its fault, Boeing spent over $500 million to retrofit the 3,000 active commercial jets in service at the time. New rudder valves and control systems were installed with the aim of preventing similar disasters. Additionally, after the crash, in response to public disputes between Boeing and the families of victims demanding accountability, Congress passed the Aviation Disaster Family Assistance Act. This legislation officially transferred the responsibility for survivor and victim services to the NTSB to better manage the legal and financial aftermath of future crashes.
5. Air Canada Flight 797
On June 2, 1983, Air Canada Flight 797 was cruising at 33,000 feet (10,058 meters) when disaster struck. The DC-9, en route from Dallas to Toronto, experienced a sudden and alarming problem. Smoke began to seep from the lavatory at the rear of the plane, raising immediate concern among the flight attendants. They promptly informed the cockpit, and the pilots, reacting quickly, requested an emergency landing as the smoke began to fill the cabin and cockpit.
It was a fortunate decision for the pilots to seek an immediate landing, for by the time they reached Cincinnati, the smoke had nearly consumed the cockpit. Despite struggling to see the instrument panel, the pilots managed to land the plane safely, bringing it to a full stop on the runway. However, just as they thought they had averted disaster, tragedy struck.
As per standard procedures, flight attendants began opening the emergency exits to evacuate passengers from the plane. However, when outside air rushed in, it ignited the combustible fumes inside, triggering an instantaneous flash fire. Tragically, of the 46 people aboard, 23 lost their lives, including Canadian folk music icon Stan Rogers. The passengers had likely thought they'd survived the worst after the plane safely landed, only to face a deadly turn of events once they were on the ground.
In response to the disaster, the FAA acted swiftly to implement new safety measures. All aircraft bathrooms were required to have functional smoke detectors, and automatic fire extinguishers had to be installed in lavatories. Additionally, seat cushions on all commercial jets were upgraded with fire-blocking layers, and illuminated floor lighting, now a standard feature on most flights, was mandated for installation. Moreover, newer planes would be constructed with more fire-resistant interior materials. These changes, all sparked by the tragic Air Canada incident of 1983, reshaped the industry forever.
4. ValuJet Flight 592
While the 1983 Air Canada incident marked a pivotal moment for the FAA in terms of enforcing anti-fire measures on board commercial airliners, it was not the only change needed in the industry. Unfortunately, just as with the earlier tragedy, it would take another devastating incident before the necessary measures were put into effect.
On May 11, 1996, ValuJet Flight 592 plummeted from the sky and crashed into a remote area of Florida’s Everglades. The descent was shockingly rapid, and the plane almost disintegrated upon impact. The FAA, horrified by the speed of the crash, began an investigation and uncovered a startling discovery about the cause of the crash—a fire had ignited in the cargo hold.
The government concluded that the fire on ValuJet Flight 592 was triggered by chemical oxygen generators that had been improperly packaged before the flight. These generators were stored incorrectly in the cargo hold, and a slight jolt during the flight activated one of them. The resulting heat ignited a fire in the cargo hold, and the oxygen from the now-operating generator only fueled the flames. The fire spread so quickly that the pilots had no chance to reach a runway in time to safely evacuate the aircraft. Tragically, all 110 people aboard were killed instantly as the plane crashed into the swamp.
In response, the FAA enforced stricter regulations, requiring all commercial aircraft cargo holds to be equipped with functional smoke detectors and automatic fire extinguishers—similar to the measures they had imposed on lavatories after the 1983 Air Canada incident. Additionally, the FAA tightened its policies regarding the transport of hazardous cargo on commercial flights.
3. Lion Air Flight 610 and Ethiopian Airlines Flight 302
Two catastrophic airline crashes within a matter of months drastically impacted the deployment of Boeing’s 737 MAX 8 aircraft. On October 29, 2018, Lion Air Flight 610 took off from Jakarta, Indonesia, only to plunge into the Java Sea shortly after takeoff. Five months later, on March 10, 2019, Ethiopian Airlines Flight 302 departed from Addis Ababa, Ethiopia, but crashed six minutes into its flight to Nairobi, Kenya. Between the two incidents, 346 people perished. The fact that both occurred so soon after one another, and both involved the new Boeing 737 MAX 8, raised serious concerns worldwide about the safety of the aircraft.
After the Ethiopian Airlines crash in early 2019, Boeing and the FAA decided to ground all 737 MAX 8 jets. As the investigation unfolded, the root cause of the crashes became clear. The aircraft was equipped with a Maneuvering Characteristics Augmentation System (MCAS), which caused problems for pilots. The system would erroneously force the plane’s nose downward, despite the pilots’ attempts to pull the plane up after takeoff.
As a result, Boeing was forced to address significant wiring issues in their grounded planes and to overhaul the flight control systems to ensure that the MCAS functioned as intended. They also introduced updated training for pilots, giving them more precise and clear information on how the system operated. By November 2020, the 737 MAX 8 was cleared to fly again. However, the troubles were far from over. In April 2021, Boeing ordered a second global grounding to address another persistent software issue. Problems continued into 2021, 2022, and early 2023, leading to concerns that the aircraft might be grounded again.
2. Air France Flight 447
Air France Flight 447 was on its way from Rio de Janeiro, Brazil, to Paris, France, during the night of June 1, 2009. However, amidst severe thunderstorms over the Atlantic Ocean, the flight lost contact with air traffic control on the western edge of Africa. After that, the plane never arrived in Paris as scheduled, prompting French authorities to immediately launch search operations to uncover what had happened.
Several days later, wreckage from the plane was found floating in the Atlantic Ocean. Over the following two years, both government and private organizations used advanced technologies to recover the fuselage, the remains of many of the 228 people who perished, and the critical black box. It was the black box that ultimately provided the answer to the mystery of the flight’s demise.
It was discovered that in the hours before the plane’s crash, the pilots of Air France Flight 447 were struggling with frozen pitot tubes. These tubes, which measure the aircraft's speed, malfunctioned as the plane leveled out at 38,000 feet (11,582 meters). In their panic over not having a speed reading, the relief pilots on duty made a drastic mistake. One of them pulled the plane into a stall that it could not recover from, leading to the tragic crash.
The black box’s findings were a revelation, confirming what many in the aviation industry had long suspected: Pilots had become overly reliant on flight computers, neglecting the core skills they were initially trained in. The fly-by-wire systems used in many Boeing and Airbus planes were also under scrutiny. However, Boeing had allowed its pilots the option to override the computer inputs if necessary.
In the aftermath of the Air France disaster, the practice of allowing pilots to override computer commands became standard procedure. More significantly, airlines began to emphasize retraining pilots, teaching them when and how to manually take control of the aircraft and fly it using the traditional methods they had learned long before, regardless of the computer data displayed.
1. TWA Flight 800
When TWA Flight 800 exploded shortly after departing New York City on July 17, 1996, the world was left in shock, waiting for an explanation. The plane appeared to have blown up mid-air for no apparent reason. Naturally, governments around the globe feared it could have been the target of a terrorist attack or military strike. With 230 lives lost on a flight bound for Paris, countless families were left mourning the devastating loss.
Incredibly, the NTSB spent months carefully reconstructing the wreckage recovered from the ocean. During this process, they definitively ruled out the possibility of a bomb or attack being the cause of the explosion. However, the exact cause remained unclear. What was known was that fumes in one of the plane’s nearly-empty off-wing fuel tanks had ignited. The question remained: why did this happen, and how could it be prevented in the future?
After an extensive investigation that spanned several years, aviation engineers concluded that the explosion was most likely caused by an electrical spark. This occurred when a wire bundle nearby short-circuited, sparking the fuel-gauge sensor located over the wing. This ignition led to a catastrophic chain of events, resulting in a rapid tragedy.
Following the tragic incident and the thorough investigation, the FAA mandated significant safety upgrades to reduce the risk of sparks from faulty or aged wiring in the wings. A major development was Boeing's creation of a fuel-inerting system, now adopted by airlines around the world. This system injects nitrogen gas into the fuel tanks to reduce the risk of electrical sparks causing explosions. It became a standard feature on all newly manufactured planes in the 21st century, and older aircraft were quickly retrofitted to ensure they adhered to the new safety protocols.
