The Facts that Emerge Post Facto

Canada to extend runway safety zones
Plan not prompted by Toronto crash, official maintains

Investigators go through the wreckage of the Air France plane that crashed into a gully Tuesday at the end of a runway at Toronto's Pearson International Airport.

OTTAWA (AP) - Transport Canada soon will require all airports to build safety areas at the ends of runways to help save lives during overruns, like the one that wrecked an Air France jet Tuesday at Toronto's Pearson International Airport.
Lucie Vignola, spokeswoman for Transport Canada, said the plan to require runway extensions did not result from Tuesday's accident in which an Air France Airbus A340 landed in a gully more than 200 yards past the end of the runway. All 309 passengers and crew escaped, some with minor injuries.

"The timing is interesting, I guess, but we've been looking at this for a few months, looking to see whether or not we needed to do this," Vignola said.

She said Transport Canada decided to go ahead with the plan after clear indications that international standards are shifting to require additional room at the end of runways.

The department has not determined how long the safety areas will be required to be, or how much time airports will have to build them, Vignola said.

Transport Canada's plans surfaced as the Air Line Pilots Association said Pearson International Airport does not meet international standards because it does not have sufficient safe areas at the end of runways, including the one where Air France Flight 358 attempted to land.

The gully near Pearson's Runway 24L has long been a source of controversy. A coroner's jury recommended filling in the gully, or extending a causeway over it, after an Air Canada DC9 aborted takeoff and ended up in the gully in 1978, killing two passengers and injuring 105 others.

"The big ravine at the end of the runway is our major concern. It has been for a number of years, even before the 1978 crash," said Bob Perkins, a Jazz pilot who serves as the Canadian air safety coordinator for the Air Line Pilots Association.

After the 1978 accident, the gully was graded so the slope was not so severe, but it was not filled in, said Steve Shaw, a spokesman for the Toronto airport.

International Civil Aviation Organization guidelines say runway-end safety areas should be about 98 yards long at the minimum and about 262 yards long where possible. These safety areas do not have to be paved but should be clearly marked and not exceed a downward slope of more than 5 percent.

The organization is planning to extend its recommendation to a safety area of 330 yards, Vignola said. But Transport Canada currently requires only a 65-yard buffer zone.

Shaw said Pearson International Airport will comply with any new Transport Canada requirements for runway-end safety areas. But he said it's too soon to say whether a longer safety area would have made a difference in the Air France accident.

Whether the new regulations will require the gully at the end of Runway 24L to be filled in remains unclear.

Another solution could include moving back the start of the runway.

Investigators, meanwhile, said Saturday that only four of the aircraft's eight doors and emergency exits were used to escape the burning jetliner.

Real Levasseur of Canada's Transportation Safety Board said two of the slides used by the passengers and crew in their rush to disembark also failed to work, even though they are supposed to unfold automatically when the emergency doors are opened.

The discovery confirms comments by many passengers and witnesses who said some of the slides and emergency exists did not function. Some aviation experts have surmised that the impact might have damaged the exit doors and chutes.
from this link

EMAS and FAA Policy on Runway Safety Areas (pdf)


Two Slides Failed  - LINK
Canada Spurned Airport Doppler

The Canadian government decided years ago not to require a special radar system that can warn immediately of sudden wind shifts and dangerous blasts at the Toronto airport where an Air France jet crash-landed Tuesday, according to Canadian officials and U.S. weather scientists who developed the system.

No Canadian airport was required to deploy the system, called Terminal Doppler Weather Radar, and none ever installed it, partly because of its cost and partly because the threat to aviation of wind shear, a sudden change in wind direction, was not perceived to be as great as in the United States. The system is now deployed at all major U.S. airports.

Another more common U.S. wind shear detection system called a Low- Level Windshear Alert System, a series of wind sensors spotted around an airport, also is not deployed in Canada, according to officials.

Preliminary reports from a Doppler radar system operated by Environment Canada near the airport indicate that a strong wind shear blast, called a microburst, hit on or near the airport just as the plane was landing, but complicated calculations lie ahead to determine its effect on the plane, according to an official with knowledge of the investigation. He did not want to be identified because only official spokesmen are supposed to discuss investigation details.

Investigators have made no determination of a cause of the crash, which led to about three dozen injuries among the 309 people aboard the Air France jet, and many factors probably contributed to the crash including weather.
"No accident is ever attributable to one cause," said John Cottreau, a spokesman for the Transportation Safety Board of Canada, which is conducting the investigation.

But it is known that unusually strong thunderstorms were hitting the area.
In fact, the weather at the airport worsened considerably just as the plane landed, sending the airport condition to a "black" designation, meaning no plane could land or take off, according to an aviation official with direct knowledge of the investigation who did not want to be identified.

It appears the plane was also hit with strong gusts of wind as it rolled down the runway, the official said.

Toronto and the area north of the Great Lakes are particularly prone to strong thunderstorms in the summer. Such storms produce phenomena that can destabilize aircraft. These phenomena caused many crashes in the United States before Doppler radar systems were deployed there, starting in the early 1990s.

"But in Canada, they don't want to spend the half million dollars it costs"
for the system at each airport, said Larry Cornman, a scientist at the National Center for Atmospheric Research in Boulder, Colorado, which helped develop the new radar in the 1980s. Cornman said he worked with Transport Canada in the mid-1990s to do a cost-benefit analysis for a radar system, but "they just didn't do anything about it."

The worst of these violent weather phenomena is called a microburst, a large shaft of cold air that starts high in a thunderstorm and flows downward with increasing speed. When it reaches the ground, it flows outward in all directions. An airplane flying into a microburst is first hit with a strong head wind, then a downdraft, then a strong tail wind. Unless the pilot reacts immediately, a plane can be robbed of lift. A microburst close to landing can also prevent a plane from touching down as a pilot intends.

Terminal Doppler Weather Radar is designed to alert an air traffic controller immediately of any wind shear phenomenon and to display in easy-to-see color graphics exactly where each phenomenon is forming and how strong it is.

While Doppler radar has not been deployed at Canadian airports, it has become fairly common at television station weather departments and at government facilities. The nearest Doppler radar to the Toronto airport was in King City, about 30 kilometers, or 20 miles, from the airport, but it was not designed to give instant warnings to aircraft.

Investigators are studying the records from the King City radar for clues, but they are hampered by the fact that the radar cannot see all the way to the ground at the airport. Because of the curvature of the earth and local obstacles, it can see nothing below 500 meters, or 1,650 feet, above the airport.

However, they already can tell that there were strong microbursts in the area, one of them nearby at the time the plane landed. There were also gust fronts and other phenomena.

Real Levasseur, the chief investigator for the Transportation Safety Board of Canada, acknowledged Thursday that a strong sudden tail wind could have given the plane a push down the runway, but "the initial landing appeared very normal." "There was no emergency declared from the part of the air crew," he said.

Louis Garneau, a spokesman for Nav Canada, which provides air traffic control services in Canada, stressed that it was Transport Canada's decision not to require Terminal Doppler Weather Radar, and that none had been deployed at any airport.

"The regulations do not require it, and there is far less wind shear in the United States than in Canada," he said.

Spokesmen for Transport Canada were tied up in the investigation process, and not immediately available.

Many questions about winds and other factors at the time of the crash may be answered by a readout of the aircraft's digital flight data recorder, which has been recovered from the burned wreckage.

Source: International Herald Tribune