Safety is the primary consideration when Boeing engineers design an airplane. In addition to meeting regulatory requirements before certification, each airplane model must meet Boeing’s time-proven design standards. Often these standards are more stringent than regulatory requirements.
Regulatory requirements include ensuring redundancy in all critical systems. Every system vital to the safe operation of an airplane has a backup, and in some cases more than one backup.
For example, twin-engine jets are designed to safely take off, fly and land even if one engine fails.
Boeing designs damage-tolerant airplanes. The airplane structure is designed to withstand 150 percent of the greatest load an airplane might encounter in commercial service.
Engineers build in this extra margin of protection to allow a pilot to safely exceed the airplane’s intended flight envelope in case of an extraordinary emergency.
Boeing airplanes are rigorously tested to ensure they meet or exceed design standards and certification requirements.
Testing also helps Boeing find and fix problems before an airplane enters service.
There are many kinds of tests. Structural strength is ensured by static and fatigue tests. Static tests apply maximum loads or pressure to validate the airplane’s ability to carry loads. These maximum loads are often far greater than any load that would be encountered under normal operational conditions.
During fatigue tests, the airplane is subjected to up to three lifetimes of normal wear and tear to help validate its durability.
The tests help establish operator maintenance and repair schedules. Testing a new airplane design can take many months or years. Tests are conducted in laboratories, wind tunnels, icing tunnels, on the ground and during flight tests.
In addition to validation tests of brand new airplane designs, each airplane that rolls off the production line is tested before delivery.
Continuous Monitoring for Continuing Enhancements
Boeing continually monitors the performance of airplanes worldwide to identify opportunities to improve safety.
In-service events are analyzed through a formal, disciplined, safety process involving Boeing experts from a variety of technical disciplines, as well as senior and executive leaders.
Executive leaders constitute the Boeing Aviation Safety Council, which formally oversees a unified safety plan rooted in the company’s long history of continuously improving the design, assembly, operation and maintenance of Boeing airplanes.
Boeing works with the U.S. Federal Aviation Administration (FAA) to thoroughly review, and if necessary act upon, data from in-service events. Boeing also works with customers to understand and address potential safety issues. If a potential safety-of-flight issue arises, Boeing recommends corrective action to airplane operators. The FAA typically issues a rule that makes mandatory the actions recommended by Boeing.
Permanent solutions must be thoroughly tested, analyzed, validated and re-certified. Where necessary, Boeing deploys interim action to assure fleet safety until a permanent solution is available.
New Technology to Enhance Safety
In addition to monitoring the worldwide fleet, Boeing develops and incorporates new technologies to enhance safety. Through research, development and collaboration, Boeing has developed sophisticated technologies that provide distinct safety advantages.
Excellent examples of how technology has made aviation safer are visible in flight deck systems designed to help pilots avoid two safety problems common in years past: windshear and controlled-flight-into-terrain (CFIT).
Predictive windshear equipment along with improved windshear-training programs for pilots has virtually eliminated that type of accident.
Similarly, the "look ahead" terrain avoidance warning systems, such as Enhanced Ground Proximity Warning System, have helped dramatically reduce CFIT accidents.
Vertical Situation Display is another safety-enhancing technology. This sophisticated system allows pilots to see at a glance potential terrain conflicts and runway overshoots at a much earlier point in time than traditional warning systems.
Apart from airplane equipment and technology, Boeing leads the industry in studying and applying human factors engineering lessons to the design of commercial airplanes.
Boeing human factors experts gather information about human abilities, limitations and other characteristics and apply the data to tools, machines, systems and processes.
Their efforts provide a better understanding of how humans can most safely and efficiently integrate with technology.
Boeing also works with the FAA and the industry to develop training aids that improve a pilot's ability to respond to challenging situations.
For example, Boeing provided an updated training aid as part of a continuing effort to reduce loss-of-control airplane accidents.
The upset recovery training aid focuses on helping flight crews recover from non-normal flight attitudes that can result from unusual weather or other "upset" conditions.
The enhanced training also increases the pilot's ability to recognize and avoid situations that can lead to airplane upsets.
Runway Situation Awareness Tools
Helping pilots prevent runway overrun excursions
At Boeing and Embraer, helping pilots prevent runway overrun excursions is a top safety focus area. There isn't just one factor that causes overruns, nor is there one simple solution to prevent them.
To help pilots adapt, Boeing and Embraer have partnered to develop and provide a shared set of flight-deck guiding and alerting tools along with new procedures and training aids for pilots.
The foundation for the Runway Situation Awareness Tools is the long-standing philosophy of both Boeing and Embraer to respect pilot control, and help pilots make timelier, better informed decisions that support safe approaches and landings.
From the approach planning phase through landing rollout and deceleration, the Runway Situation Awareness Tools provide a combination of solutions to reduce runway excursions.
Participating in Accident Investigations
Although Boeing's safety efforts primarily focus on preventing accidents from occurring in the first place, a great deal of effort goes into supporting accident investigations.
Accidents are rarely caused by a single failure or action. They most often result from a chain of events. Remove any link in the chain and the accident can be avoided. Industry and government safety experts study accidents to identify these chains of events as well as "intervention strategies" for preventing the same kinds of accidents in the future.
These strategies include new training aids for flight crews and mechanics, new operating procedures, infrastructure improvements, airplane-design modifications, and incorporation of new technologies into the aviation system. Working together, industry and government safety officials have been able to virtually eliminate some of the most common accident causes of the past and are confident they'll be able to continue to make air travel even safer.
What Happens When an Accident Occurs?
The airport operator will handle firefighting and rescue operations if the accident is at or near the airport. If not near an airport, local police and fire fighters quickly take control of the site to facilitate search and rescue and to protect important evidence.
The U.S. National Transportation Safety Board (if the event occurs in the United States), or the government with jurisdiction over the area, is immediately notified.
The affected airline is the responsible source of information about the passengers and crew on board. It will not identify victims prior to notifying next of kin. The airline typically will conduct media briefings from both the accident site and its headquarters.
The airplane manufacturer and engine manufacturer will be involved in the accident investigation, if called upon by the government agency leading the investigation.
How Accidents are Investigated
Accident investigations are led by the country where the accident occurs. If it occurs over international waters or the airplane is missing, the investigation is conducted by the country where the airplane is registered.
Investigators from other countries usually are invited to assist. Sometimes, one of them is asked to lead the investigation.
The investigator in charge oversees all testing and analysis of wreckage, and is responsible for communicating with all stakeholders and the public.
Advisors can be appointed to provide technical expertise. They usually are representatives of the airplane and engine manufacturer, the operator and other appropriate parties.
Always important to an investigation are the "black boxes"—the cockpit voice recorder and flight data recorder, which are encased in steel boxes located in the tail of every airplane and capable of withstanding great pressure and temperature extremes.
The accident investigation’s final report often takes years to complete. It contains probable cause, as well as safety recommendations.
A Word About Accident Statistics
Boeing is committed to its role in helping all stakeholders understand the data associated with airplane accidents. That is why, since the 1960s, Boeing has published the Statistical Summary of Commercial Jet Airplane Accidents. The annual report has become the definitive source of air accident information for the aviation industry. By understanding what the data is telling us, we, as an industry, can take meaningful steps toward enhancing the safety of the air transportation system.
Working Together to Make Sure Flying Is as Safe as Possible
Aviation safety is the combined result of:
Airplane design and production
Airline operation and maintenance
Air traffic and airport –infrastructure
Boeing joins with governments and the industry to continuously advance safety in all aspects of the global air transportation system. This collaborative approach is more effective than regulatory action alone.
Boeing continuously works with members of industry, civil aviation associations, government regulatory authorities and operators to ensure safety efforts are effective and aligned worldwide.
Commercial Aviation Safety Team
An example of this collaboration is the Commercial Aviation Safety Team (CAST), which comprises representatives from airlines, manufacturers, labor and government.
Established in 1998, CAST has helped reduce the fatal accident rate in the U.S. by 83 percent in the 10-year period from 1998 to 2007 by systematically analyzing data from accidents and safety incidents worldwide. CAST developed more than 96 safety enhancements to date and has implemented more than half of them so far.
Safety efforts rely on investigating past incidents and accidents to prevent future ones and by examining aviation operational data to identify less obvious or emerging patterns and potential conditions before accidents occur.
Industry Safety Strategy
Boeing collaborates with industry organizations and governments to help regions throughout the world to develop effective plans for improving aviation system safety.
Working together, the aviation industry is improving safety by sharing the knowledge of regulators, operators and manufacturers.
Industry efforts identify aviation safety risks and introduce best practices to develop and prioritize of safety initiatives while ensuring that these safety initiatives are coordinated and consistent worldwide.
Through collaborative efforts and continuous monitoring of the in-service fleet the global aviation system is safe and will continues to improve in the years to come.
Frequently Asked Questions
Are four engines better than two?
Commercial airplanes with two, three and four engines are safe. In fact, the record shows that twinjets have fewer engine problems than airplanes with more than two engines.
What's more, twinjets are designed to fly on only one engine for extended periods of time, and routes are laid out to keep them within a safe distance of an airport at all times, just in case an engine fails.
What are the chances of both engines failing at the same time? The probability of that happening on a twin jet is less than one in a billion flight hours.
About 96 percent of jetliners delivered today are twinjets. They safely serve every type of route, from short-haul shuttle flights to the longest globe-spanning nonstop flights.
Are older airplanes safe?
Older airplanes have to meet stringent safety requirements. The key to keeping them safe is good maintenance, and there are extensive maintenance requirements for all airplanes, young and old, that airlines typically exceed.
In the early '90s those requirements were stiffened for older planes. As airplanes reach certain operational milestones, airlines perform extensive inspections and modifications to the airplane's structure. Sections of skin are replaced. So are door frames, lines of rivets and other structure that may weaken from repeated pressurization and environmental conditions encountered through the years. All of this is done according to a scheduled maintenance plan that's based on years of operating experience.
Many older airplanes also have the latest avionics systems aboard. If an airline decides to keep an airplane in service, it often incorporates new systems that help flight crews do their jobs more efficiently and safely. In fact, the FAA has mandated some of them—like collision avoidance and ground proximity warning systems.
Are some models safer than others?
Some models have been involved in more accidents than others, but that's because they're more widely used. The only valid comparison to make is of accident rates—that is, the number of accidents per million departures for each model of airplanes.
When we do that kind of comparison of western-built commercial jets, what we see is that all of these jets have extremely good safety records. There are slight differences in the accident rate from model to model, but none that would support the conclusion that some airplane models are safer than others—especially since accident investigators have found the airplane itself the primary cause of a very small percentage of the serious accidents.
The fact that all models have extremely good safety records is not surprising. All commercial airplanes, whether designed and manufactured by Boeing or by some other company, must meet the same stringent safety requirements before they are certified to enter service.
Are some parts of a flight more at risk?
Some parts are statistically riskier than others although none are anywhere near as risky as many of the other things people regularly do, like drive a car. Airplane travel consists of three phases:
Takeoff and climb
Descent, approach and landing
Looking at accident rates for each phase, cruise is the safest part of flying. Only about 8 percent of all accidents occur during this phase. Approximately 30 percent of all fatal accidents occur during takeoff and climb. Nearly 50 percent of fatal accidents occur during descent, approach and landing. (Note: The remaining 12 percent of fatal accidents occur during non-flight phases including taxi, passenger boarding, etc.)
Because so few accidents occur during cruise, long flights are no riskier than short ones.
Can the doors open in flight?
It is impossible to open the door once an airplane is airborne and pressurized.
If an emergency landing is necessary, as the airplane descends, the pilots slowly depressurize the airplane, so the doors can open immediately after the airplane touches down. Emergency exits are designed to open once an airplane has landed.
Can the wings break off?
Actually, they can, given enough force. For every new model Boeing designs, the wings are bent until they break. Breaking a wing requires far more force than anyone has ever come close to experiencing in actual flight. You may see the wings flapping a bit during turbulence. They're designed to be flexible, in part to ensure they don't fracture. Airplane wings are very strong.
What are those weird noises we hear during flight?
Airplanes are complex machines, so it's common to hear a lot of unusual sounds. Here are some of them:
Drilling sound prior to takeoff and on approach to landing—Panels on the wings are being extend to facilitate low-speed flying. They are driven by a screw mechanism that causes the noise you hear.
High-pitched whine prior to takeoff—Engines are spooling up for takeoff. At cruise altitude, the pilot will throttle the engines back, and the engines sound more like a hum than a whine.
Rattling during takeoff or turbulence—Items stored in overhead bins and other parts of the cabin get jostled by engine vibrations on takeoff or turbulence during flight.
Thump beneath the floor following takeoff—Landing gear doors being shut.
Loud roar following touchdown—To help slow the airplane after landing, thrust reversers literally reverse the flow of the air through the engines, making them loud. Thrust reversers help save wear and tear on the braking system.
Where's the safest place to sit on an airplane?
While some people believe the safest spot is near the wings or toward the rear of the cabin, there's no conclusive evidence to support either theory. One seat is as safe as another, especially if you stay buckled up.
Why can't airplanes be as strong as black boxes?
They could, but then they would be too heavy to get off the ground.
The so-called black boxes house the flight data recorders and cockpit voice recorders that investigators use to help them determine the cause of a crash. They are made of steel so they can survive the impact of a crash as well as fire and immersion in water. Steel is much too heavy for an airplane, which mostly is made of aluminum and various lightweight composite materials.
Still, airplanes are designed to be strong as well as lightweight. In many of the accidents that have occurred, the airframe has remained largely intact following impact with the ground.
What can passengers do to ensure safety?
Safe air travel is a shared responsibility. Just as government regulators, manufacturers and members of the airline industry play a major role, passengers can do many things to enhance their safety and comfort during air travel:
Pay attention to the flight attendants.
Listen to safety briefings, even if you've heard them many times.
Review the safety data card in the seat pocket in front of you.
Locate the emergency exits. Because airplanes have different configurations, it's important to look around you once you're in your seat.
Count the number of rows between your seat and the closest exit, and remember, sometimes the nearest exit is behind you.
Keep your seat belt fastened while seated. Turbulence can strike at any time.
When traveling with an infant or child under age two, consider purchasing a separate seat.
Buckle your child into an approved-for-flying car seat.
On long flights, exercise your arm and leg muscles.
What to wear on an airplane flight is more a question of safety than fashion. What you wear matters. In the event of an evacuation or emergency landing, you'll want to protect your body.
Here are some air safety fashion tips:
Wear natural fibers such as cotton, wool, silk or leather, which offer the best protection in the event of a fire or evacuation.
Avoid synthetics such as nylon, rayon or poly-cotton blends, which can melt when heated.
Skip the short skirts, shorts and skimpy T-shirts. Protect your arms and legs.
Opt for closed-toed shoes with secure laces or straps. Leave the flip-flops, sandals or high-heel shoes in your luggage. In fact, high heels can puncture an escape slide. In an emergency, you'll be asked to remove high heels.
Ensure that your clothes aren't tight, uncomfortable or restrictive. You'll need to move quickly and easily in an emergency situation.
Traveling with children
Whether you are traveling across town or across the country, traveling with children requires patience, planning and attention to safety issues. Air travel is incredibly safe—far safer than going by car.
One of the most effective things you can do to ensure your child's safe air travel is to listen to all announcements.
Pay attention to the safety briefing and read the safety card in the seat pocket in front of you.
Keep your child's seat belt fastened throughout the entire flight and set a good example by keeping your safety belt fastened too.
If you are traveling with an infant under two years of age, it's a good idea to purchase a separate seat for your child and bring along a government-approved child safety seat.
Strap the safety seat into the airline seat and your child into the safety seat, facing backwards. Your child will be much safer if turbulence is encountered during the flight or in the unlikely event of an accident.
If you've ever been on an airplane, the odds are that you've experienced some turbulence.
Turbulence is that bumpy, choppy sensation you feel as the airplane hits a rough air pocket. Turbulence can range from slight to severe bouncing, pitching and rolling. Even mild turbulence can shift objects in the overhead bins and send drinks flying off tray tables.
Severe turbulence can make walking difficult and send loose items flying about the cabin.
You can be assured that the airplane is built to withstand these conditions. However, severe turbulence can result in injuries.
Here are some strategies to protect yourself from the effects of turbulence:
Always wear your seat belt when seated.
Hold on to the seat backs or overhead bins when walking in the cabin.
Listen to all safety announcements and follow flight crew instructions.
Remain calm if turbulence occurs.
Be careful when opening overhead bins following turbulence.
Emergency evacuations are rare and most are precautionary. In the unlikely event you experience an evacuation, you should:
Try to remain calm.
Listen to and follow instructions from the flight crew.
Check to see if the closest exit is behind you.
Leave your carry-on items aboard the airplane.
Wear sturdy comfortable shoes when flying.
Airplanes have numerous features to help facilitate a speedy evacuation.
Escape-path lighting will help passengers find their way to the exits in low-visibility conditions.
Slides will deploy from each of the exits so passengers can get safely to the ground.
If the airplane is in water, the slides can be used as life rafts. Seat cushions also double as floatation devices. They are easily removed and carried in an emergency.
Airplanes used on oceanic routes also have inflatable life rafts on board and a life vest under each seat.
Pressurized cabin air systems control airflow, air filtration and temperature.
Prior to takeoff, flight attendants instruct passengers on how to use the oxygen masks should the passenger cabin depressurize.
Cabin depressurizations are extremely rare events. In fact, airplanes are built with redundancies in place to prevent such occurrences.
In the unlikely event your airplane does depressurize, the flight crew will perform a rapid descent to approximately 10,000 feet, where no supplemental oxygen is needed.
Once the airplane is stabilized at this altitude, the pilots will divert and land at the closest available airport.
Here are a few tips for dealing with cabin depressurization:
Stay calm and breathe normally.
Pull sharply on the oxygen mask that will automatically drop in front of you to get the oxygen flowing.
Put the mask over your mouth and nose, then tighten the strap.
If you are traveling with a small child or an infant, put your mask on first, then help the child.
With more people flying farther and more frequently, onboard medical emergencies are becoming more common.
All airplanes are equipped with basic medical kits, and airlines train their flight crews to handle some of the more common medical situations. Often there's also a doctor or nurse on the flight who is willing to help with an emergency.
Many airlines have begun equipping airplanes with automatic external defibrillators to be used if a passenger suffers a heart attack.
Onboard telephones and radios facilitate consultations with ground-based medical personnel. In the future, enhanced audio and video technology will make it possible to transmit a passenger's vital signs directly to advisors on the ground.
If needed, pilots also will divert a flight to the closest airport with a hospital or other medical facility nearby.