Boeing and Aviation Safety

Frequently Asked Questions (FAQs)

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.

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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.

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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 aircraft.

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.

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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.
  • Cruise.
  • 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.

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Can the doors open in flight?

Hollywood has made quite a few thrillers through the years depicting people getting sucked out of airplanes. It's some people's worst nightmare! It's also extremely unlikely.

First of all, commercial jets are made of extremely strong materials. The materials are lightweight, but the airplane structure is designed to be incredibly strong. It's also designed to be "fault tolerant," meaning that if one part of the structure fails, other parts will take up the loads and the airplane will continue to fly safely. There's also a comprehensive program in place to ensure the structural integrity of older planes through periodic inspections, replacement of structural components, and modifications.

As for the doors, they cannot be opened once an airplane is airborne and pressurized.

To facilitate breathing and passenger comfort, airplanes are pressurized to the equivalent atmosphere of 8,000 feet. Since airplanes typically cruise above 30,000 feet, the air pressure inside the plane is much greater than the pressure outside -- and that pressure differential makes it impossible to open the door, even if somebody wanted to do such a thing.

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.

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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.

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What are those weird noises we hear during flight?

In the early days of aviation it was common for people to refer to airplanes as "flying machines" -- and that's exactly what they are. When you're flying, you're inside a large, complex machine, so it's common to hear a lot of strange sounds. Here are some of them:

A drilling sound prior to takeoff and on approach to landing-- That's the sound of the flaps and slats being extended on the wings. These panels, which increase the area and curvature of the wing when extended to facilitate low-speed flying, are driven by a screw mechanism that causes the noise you hear.

A high-pitched whine prior to takeoff-- That's the sound of the engines spooling up for takeoff. Once airborne, the pilot will throttle the engines back, and during cruise the sound of the engines becomes more of a hum than a whine.

Rattling during takeoff or turbulence-- That's the sounds of things being jostled in overhead bins and other parts of the cabin due to engine vibrations on takeoff or turbulence during flight.

A thump beneath the floor following takeoff-- That's the landing gear going up into the belly of the airplane and the doors to the landing gear bay being shut.

A loud roar following touchdown-- That's the sound of the thrust reversers, which help slow the airplane once it's on the runway. They literally reverse the flow of the air through the engines, which is why they are so loud. Airplanes are designed to stop using brakes alone, but flight crews typically deploy the thrust reversers to help save wear and tear on the braking system.

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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.

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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.

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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.

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Fashionable flying

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.

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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.

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Turbulence

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.

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Emergency evacuation

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.

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Cabin Depressurization

Airplanes are pressurized to a maximum of 8,000 feet. Typical airplane cabin altitudes are 6,000 to 7,000 feet. The cabin is pressurized by the cabin air system, which also controls airflow, air filtration and temperature.

Before each and every flight takes to the sky, flight attendants conduct a safety briefing for all passengers. As part of this routine, passengers are instructed on how to handle a cabin depressurization, including how to use the oxygen masks that will automatically deploy.

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:

  • Try to 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.

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Medical Emergencies

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.

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