Are Some Airlines Just Too Dangerous to Fly?

In the first days after it fell into the Indian Ocean in late June, Yemenia Airways Flight 626 appeared to be a typical example of slack practices by airlines operated from Africa and the Middle East.

The flight started in Paris on a newer plane but switched to a 19-year-old Airbus A310-324 for the second leg of its journey from Sana'a, Yemen, to Moroni in the Comoros Islands, which the pilot approached in high winds. Out of 153 crew members and passengers only one survived, a teenager named Bahia Bakari, who floated until her rescue by clinging to debris. European officials talked of banning Yemenia after the crash, but the cause remains unknown — the flight's black box hadn't been recovered — and they backed away from the idea in mid-July.

The real problem exposed by the aftermath of Flight 626 — how to make sure old planes are fit to fly by standardizing worldwide aircraft maintenance — has opened a rift in civil aviation as wide as the wings of a 747.

An article in the May edition of the Journal of Business and Economics Research could help close it. Two professors at Embry-Riddle Aeronautical University in Daytona Beach, Fla., looked at 476 accidents between 2000 and 2007, excluding accidents caused by hurricanes or hijackings but not those linked to pilot error. They found that old planes used for commercial aviation with 19 or more seats have more accidents when operated from Latin America, the Middle East and Africa.

"When you look at the record, on the bottom of the pile are Africa and Asian countries because most of the time they are flying older aircraft," says Bijan Vasigh, an aviation economist and study co-author.

Most of the accidents involve aircraft 15 to 24 years old, report Vasigh and co-author Jorge M. Herrera (who has since left Embry-Riddle). The two excluded accidents caused by weather or terrorism, and divided the accidents according to phases of flight, such as approach and landing, the most dangerous time when the pilot is busiest. Equipment made by McDonnell Douglas (merged with Boeing since 1997) is among the oldest still used around the world and has accidents at the rate of 14 per 1,000 aircraft, or 14 times as often as equipment manufactured by Airbus, a younger company with fewer old planes in use.

(Vasigh says he concentrated on the big three manufacturers, Airbus, Boeing and McDonnell Douglas, because their equipment carried more people around the world, rather than include Russian-made jets, which are known for being involved in many accidents but aren't used much outside the developing world. "Most of the Russian aircraft are flying in the Third World where safety practices are poorer and the accidents result from safety lapses, such as exceeding takeoff weight maximums and human error," he says. Focusing on the Russian aircraft "could have really distorted the data.")

Developing nations often assemble jet fleets by leasing or paying cash for clunkers. Oddly, the plane used in Flight 626, according to several media reports, was leased from a subsidiary of AIG, the giant insurer now controlled by the U.S. government. (Yemenia Airways did not respond to questions in phone calls or e-mails.)

Keeping planes up in the air is another way to hold down costs; when it comes to safety, flight cycles and hours of engine operation matter more than chronological age. If old planes are used beyond their designed economic life, as is increasingly the case, they need constant maintenance. Put the plane in countries that interpret transparency differently and where scant resources limit money, training, labor and spare parts, and care may fall short of international standards.

Developed countries aren't immune to aging aircraft problems, but in the U.S. enforcement is stronger. Southwest Airlines, a low-cost U.S.-based carrier, missed some inspections on some older Boeing 737s, and last year subsequent inspections found cracks in six aircraft. This past March, the airline agreed to pay a $7.5-million penalty in a settlement with the U.S. Federal Aviation Administration. Southwest also agreed to enact new maintenance procedures.