By Fred Vallance-Jones, Robert Cribb and Tamsin Mcmahon
The Hamilton Spectator
(Jun 10, 2006)

When the pilot of an Air Georgian business jet flying to Toronto started to lose cabin pressure in 2003, he did what crews are trained to do.

He shoved the plane into an emergency descent.

With just minutes of oxygen available in the emergency supply, he had to get the plane down to breathable air -- and fast.

But in a nearly catastrophic twist, the manoeuvre meant to save lives instead sent the seven-passenger Cessna Citation plane swooping into the path of a Delta Air Lines MD-80 airliner.

Only a sophisticated collision avoidance system prompted the Delta pilot to take evasive action, saving as many as 140 lives.

The cause of the depressurization was later discovered to be a faulty door seal -- a problem that had been showing up sporadically in joint U.S.-Canadian data on the Cessna since 1996, yet had never been addressed by Canada's airline regulator, Transport Canada.

It's one example that highlights what experts say is a major issue in the airline industry: Many safety problems have been found only after they killed people, leading to so-called "tombstone improvements."

Experts say the industry needs to do a better job identifying trends in mechanical problems that, however small, can lead to a plane going down.

Transport Canada says it doesn't see any disturbing overall trends in mechanical problems since 2000.

But a joint investigation into airline safety by The Hamilton Spectator, Toronto Star and The Record of Waterloo Region found the same kinds of maintenance problems can crop up time after time -- with no permanent fixes.

The investigation also revealed that many types of mechanical malfunctions have been rising, even though the number of takeoffs and landings has decreased.

The newspapers analysed more than 50,000 incident reports made to Transport Canada and obtained through an access to information request.

The data show an aviation system susceptible to a wide array of problems, including planes that get too close to each other in the sky, that have put more than 80,000 passengers at risk over the past five years.

In 2004, there were close to 1,800 mechanical incidents reported.

Incidents of depressurization were up 23 per cent from 2000 to 2004.

The most serious -- forcing emergency descents like in the Air Georgian case -- are rarer, with 10 last year involving commercial planes, according to the Transportation Safety Board (TSB), which investigates airline incidents.

The air leak in the Air Georgian plane was first noticed by a passenger who heard a whistling sound coming from the door, says a TSB incident report.

The whistle turned to a roar, with pressurized air sluicing past a faulty door seal. The noise was so loud the pilots couldn't hear the urgent calls from air traffic controllers to stop losing altitude, and when they did, it was too late to prevent the near collision.

The Transport Canada incident report later said the plane had originated in the Turks and Caicos Islands where it was exposed to high humidity. Then, at a stopover in Georgia, it was raining. All that water seeped into the door seal and froze at a high altitude, leading to the depressurization and the Cessna's emergency landing.

Neither Mississauga-based Air Georgian nor Delta would comment on the emergency.

Cessna indicated to Air Georgian that "they have had a few like incidents reported before" and recommended checking the door seals in high humidity conditions, the incident report says.

U.S. data show as early as 1996 there had been sporadic reports of Cessna Citation door seals failing because of water, including three that forced emergency descents. All of the emergency descents involved Canadian planes, although the data don't reveal who the operators were.

Loss of cabin pressure can quickly lead to unconsciousness for crew and passengers, turning aircraft into ghost planes that careen to the ground when they run out of fuel.

Professional golfer Payne Stewart was killed in just such a crash in 1999 and a depressurized Helios Airways 737 crashed into a mountain in Greece last year killing 121.

Halifax aviation consultant Alex Richman says that -- ironically -- had there been a crash between the Cessna and the Delta airliner, the door seal problem would have got a lot more attention than it did.

The system to fix mechanical defects is flawed, Richman says.

"As much attention has to be paid to rare events as is paid to frequent events," Richman said.

Richman says a lot of problems go undetected.

"The fatal accident rate has decreased markedly, but has remained constant the last 10 years and more attention has to be paid to the precursors and the less severe problems which may lead to an accident," says Richman, an epidemiologist who once practised in New York City and now puts his medical background to work analysing aviation data and flagging emerging problems for commercial clients.

Many of the mechanical incidents in the Transport Canada data had the potential to be disastrous -- including disintegrating tires tearing into wings and fuselages, fiery engine failures and critical parts falling off aircraft.

Unscheduled landings caused by mechanical problems have, conservatively, affected at least 50,000 passengers in Canada since 2000, the analysis shows.

Airlines and cargo operators point out these kinds of failures are rare when compared to the thousands of daily flights.

One of the jobs of Transport Canada -- and the Federal Aviation Administration in the U.S. -- is to avoid potential disasters by making sure endemic failures are fixed.

It collects what are known as "service difficulty reports" from airlines -- who are obligated to report problems -- and puts them in a database.

The regulators look for patterns in the data, then send advisories or, in the case of the most serious problems, airworthiness directives to manufacturers and operators. The directives contain mandatory repairs to be completed within a set period of time.

Critics maintain the system isn't up to the job of detecting problems in today's evermore-sophisticated planes.

"As the airplanes are getting more complex, our system for managing these more complex aircraft hasn't kept pace," said John Eakin, a Texas aviation consultant who has studied aviation safety data for 15 years. He entered the field after being trapped in a helicopter that crashed in 1984.

One example of the technological gap between planes and the safety system comes from the flight of an Air Transat Airbus A310 in March 2005.

Its rudder snapped off after the plane left Cuba for Quebec City. The pilots were able to maintain control and limp back to Cuba.

The rudders are made of composites -- new-age materials held together by glue-like substances. Composites are stronger and lighter than the aluminum traditionally used in aircraft, but how they age and decay is not fully understood.

The incident remains under investigation by the Transportation Safety Board, but after problems were found in a similar Federal Express aircraft in November 2005, the TSB issued urgent recommendations for stepped-up rudder inspections.

Service difficulty reports on such incidents are supposed to be filed with Transport Canada or the FAA within days of an occurrence.

But Eakin says not only do some carriers fail to report service difficulties as required, but the data itself is of inconsistent quality.

Like Richman, Eakin also advocates more investigation of incidents that don't lead to calamity.

"Incidents are so much more valuable than the accidents," he says. "Usually, at least, there is a live pilot to talk to. But incidents don't get investigated."

In Canada, the TSB only investigates about 50 air occurrences a year and, as in the U.S., most of those are the more dramatic ones.

Still, the TSB has had its own concerns about aircraft defects.

In its 2000-2001 annual report, the board raised a number of "significant air safety issues" related to maintenance.

"Accidents and incidents involving maintenance procedures and logbook-keeping, human errors on the part of aircraft maintenance engineers, and the inadequate supervision of maintenance apprentices have risen significantly in recent years," the report said.

While technological advancements have improved reliability, it added, they have also added complexity that requires attention to detail and expertise from the people tasked with maintenance.

The board has not pursued the issue since, said Nick Stoss, TSB director of air investigations.

Airlines do have their own internal systems for tracking mechanical problems.

One of those systems is run by Halifax-based CanJet airlines. It feeds all inflight problems in its small fleet of Boeing 737s into a computer system.

"The software package has a built-in feature that will flag us in the event a defect of the same category is raised three times in 15 flights," said James Penwell, CanJet's director of maintenance.

"If three defects are reported (in one or more planes), it will flag us to say, 'Guys, it's time to take a look here.'"

CanJet was to upgrade to a more sophisticated system this month, and also has access to Boeing's in-house database of in-service defects. Air Canada has an even more sophisticated system that downloads flight data automatically from its Airbus planes.

Some of the more common mechanical problems include hydraulic malfunctions and reports of smoke in the cabin or cockpit.

They each account for about 100 Transport Canada incident reports a year.

In October 2004, a First Air Boeing 727 had just pulled away from the gate in Ottawa when oily hydraulic fluid began leaking from a pinhole leak in a hose and was sprayed into the plane's heating system.

Panicked travellers gasped and grabbed for pillows to protect their mouths and eyes from the burning mist.

Dianna Patryluk of Cape Dorset, Nunavut, watched helplessly as the choking wave surged toward her.

"People behind us were already panicking before it got to us.

"And then, when I say it was burning, it was your throat that was burning and it felt like it was closing up."

The plane had just pulled from the gate in Ottawa for a routine shuttle to Iqaluit on Baffin Island. "It really did feel like you weren't going to get out of there," said Patryluk.

Eventually, the passengers were hustled off using the back stairs. Several were treated by paramedics, but Patryluk says she still has problems with her eyes.

First Air plays down the drama, saying mechanical incidents happen.

"These are mechanical parts we are dealing with, and mechanical parts -- no matter how stringent an airline maintenance procedure is -- mechanical parts do fail from time to time" said Jim Balingall, an airline spokesperson.

"That aircraft was evacuated without incident and the passengers were treated according to our emergency response procedures."

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