Plane crashes are more survivable than ever

Concerns prompted by the recent spate of fatal airplane mishaps overshadowthe overall improvements to airplane safety over the years andthesurvivability of many crashes, aviation experts say.

There are many improvements in technology to prevent the accident in the first place,"said Rudy Quevedo, director of technical programs of the Flight Safety Foundation. And beyond that, if you were to get into an accident,there have been improvements into the way aircraft have been built, vulnerability of the interiors so that all collectively enhances the chances of survival.

An oft-cited study conducted by the U.S. National Transportation Safety Board in 2001 looking at the survivability rates from 1983 to 2000 of U.S. air carrier flights found that in the 568 plane accidents during that time period, 95.7 per cent of the occupants survived.And of the seriousaccidents (26)involving fire, substantial aircraft damage or complete destruction, 55.6 per cent of the occupants survived.

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Although 2014 has been a particularly bad year for airplane fatalities, last year was considered one of the safest years ever, with19 aviation accidents worldwide involving deaths.

Runway excursions most survivable

"One ofthe largest factors is the type of accident," Quevedo said. "That, to a great degree, dictates the survivability rate."

Generally, the three most common types of accidents that cause the most fatalities are classified as:

• Runway excursions.
• Controlled flight into terrain.
• Loss of control in flight.

The most common, and most survivable, are runway excursions, where the plane departs the surface of the runway either at the end of the runway oroff to the side.

Controlled flight into terrainoccurs when a pilot still has control but the airplane impacts into some kind of terrain, whether it be land, water or some kind of structure.

Generally the least common accident, but the type most likely to be fatal, occurs when the pilot, for whateverreason, completely loses control of the flight.

The survivability of some crashesoften depends on the impact angle how steep the plane comes in and hits the terrain and impact velocity, saidAnthony Brickhouse, associateprofessor of appliedaviation sciences at the Embry-Riddle Aeronautical University in Florida.

"We have designed planes withstructuresthat absorb the energy and keep the energy awayfromthe occupants for as long as possible," he said.

Those crashes deemed to be non-survivable are those where the G-forces aretoo high and the structure is no longer intact, meaning the airplane just crumplesand kills the people inside, Brickhouse said.

Planes designed to glide

Brickhousenoted there's a big misconception about what happens to anaircraft if it loses power, with many believingthatit will just drop out of the sky.

"That's just not true," he said.

Planes are designed to be able to glide a certain distance, based on various factors, including weather conditions and pilot skill.

Chesley (Sully)Sullenberger, the pilot of US Airways Flight 1549, was able to glide his plane to a safe landing in the Hudson River in 2009 in the so-called "miracle on the Hudson."

A number of changes to aircraft have been made over the past decades that have increased crashsurvivability. Structural enhancements to the planes, includingchanges to seats, have given passengers a better chance of surviving accidents.

Twenty years ago, seats were made to withstand nineGs before they would break from their moorings. Now they're made to withstand 16 Gsof force.

Todd Curtis, former Boeing safetyengineer and founder ofAirsafe.com,said all sorts of evolutionary designs with new aircraft make it less likely people die after a crash. Some passengers will survive the impact of a crash but die in a subsequent fire, butfire-resistantmaterials have become standard in all aircraftand are less likely to generate noxious fumes.

Improvementof flight crew training has also made a significant difference, Quevedo said."Without the actionsof the flightattendants,those improvements wouldn't be as effective."

Flight attendants were praised for their role when Air France Flight 358, carrying more than 300 people on board, ranoff the runway of Toronto's Pearson International Airportand burst into flames in August 2005. No one was killed in that crash.

"That was anoutstanding example of aircraft design, proceduresand just the basic understanding on the part of passengers and crew of what to do in an emergency," Curtis said.

Emergencyresponse to crashesis also crucial. In 1999, a China Airline flight carrying more than 300 people on boardflipped upside down and caught fire at Hong Kong International Airport. But the "first rate"rapid response of the crash fire rescue service, which wason the scene quickly and able to put down the fire and get everyone out, resulted in only three passengers killed, a fatality rate extremely low considering the nature of the crash,Curtis said

Rescuers make the difference

"I can cite case after case where had the rescue people not been there, no one would have survived or there would have been far fewer survivors,"Curtis said.

Accidents also lead toimprovements to safety,said James Hall, a formerNTSBchairman.For example, the fatal crash of US Air Flight 427 prompted the redesign of the Boeing 737 rudder;wiring changes to theMcDonnell Douglas MD-11 were implemented after the crash of Swissair Flight 111

"Each one of these tragedies is mined forcefully by the investigators in terms of survivor factors,"he said.

Hall said that because many accidents are indeed survivable, passengers, including frequent flyers, should pay attention to the routine announcements before takeoff.

"Those routine announcements, those exits those lights on the floor, paying attention to the closet exit thats life-saving information."