The Cute, the Hairy And the Scaly: Pests That Ground 747s

Source: Wall Street Journal
Author: Danial Michaels

Qatar Airways Flight 645 to Doha was loaded and almost ready to leave Manila airport, when it was held because of an unwanted passenger. It was a mouse.

After a frantic hunt and two rodent sightings in the cabin, the captain ordered all 243 ticketed passengers off the plane, which was towed to a hangar for fumigation. The Sept. 28 flight left 13 hours late. The mouse was found dead.

Every year, planes around the globe are held up by mice, rats, snakes, spiders and other unwanted stowaways.

Every year, planes around the globe are held up by mice, rats, snakes, spiders and other unwanted stowaways. Insects and reptiles can terrify passengers, though they rarely pose a health threat. Airlines worry that despite back-up systems, some well-placed nibbling by a rodent could hobble a 100-ton, $200 million aircraft. Risks range from knocking out a reading light, to sparking a fire, or even crashing a jumbo jet by severing the networks for control, navigation or communication.

"If rats gnaw on a cable, who knows what they're going to do?" says Paul Hayes, director of flight safety at aviation consultants Airclaims PLC, in the United Kingdom.

In July 2002, a pit bull terrier escaped from its cage in the cargo hold of an American Airlines flight from San Diego to New York, chewed up parts of the plane and gnawed on electrical cables as thick as a garden hose. The Boeing 757 was out of service for nine days of repairs.

No plane crash caused by stowaway animals has been recorded, according to Mr. Hayes. And animal-related delays are a minor financial concern, compared with the billions of dollars carriers lose each year from surging fuel prices and ballooning security costs. Still, tiny creatures cost airlines several million dollars annually in schedule disruptions and pest control, officials estimate.

On Feb. 22, for example, a spider fell from an overhead luggage bin as passengers exited an Air France flight to Manchester, England, delaying the Airbus's return to Paris by five hours. The spider wasn't found, but witnesses said it was big and hairy.

In February 1998, a Swissair Airbus A310 bound for Vienna was grounded for two days by a rat, recalls Jean-Claude Donzel, who was a spokesman at the carrier and now works for its successor, Swiss International Air Lines. Mr. Donzel has since kept a loose-animal file, which includes nine subsequent incidents at Swissair and Swiss.

The latest entry was on Nov. 11, when Swiss delayed a flight from Zurich to Moscow by 75 minutes after an 8-inch orange snake was spotted. The serpent escaped from the pocket of a young man, who had slipped it past U.S. security agents while boarding an earlier Swiss flight from New York, says spokeswoman Elle Steinbrecher. A veterinarian in Zurich determined from descriptions that the reptile wasn't poisonous. Still, Swiss put its 76 passengers on a different aircraft and had the original Airbus A320 fumigated.

"Even though it was harmless, if I were a passenger, I wouldn't like a snake on my seat," says Ms. Steinbrecher.

"Even though it was harmless, if I were a passenger, I wouldn't like a snake on my seat," says Ms. Steinbrecher.

The airline didn't consider unleashing one of the snake's natural predators, the mongoose. In April 2000 Swissair had to ground a flight arriving from Africa after one of those got loose.

Paul Burland faced a rodent incident on a British Airways Boeing 747, just before it left London's Heathrow airport for New York, in 1995. "At first it seemed a bit comical" when passengers were ordered off the plane, he recalls. He assumed staff would quickly catch the rodent, but the eight-hour delay was less funny.

Traps and Pads

To snare small animals, technicians like Peter Pfister first try traps or pads of glue. Mr. Pfister, the technical fleet manager for Airbus aircraft at Swiss maintenance group SR Technics Holding in Zurich, says he has staged onboard critter hunts about two or three times annually over his 30-year career. In the 1998 Swissair case, his team bagged the mouse with an old-fashioned trap, baited with cured ham.

If ham and cheese fail, staff can scan a plane with infrared cameras. Mr. Pfister says this works well when chasing warm-blooded creatures like rats, but isn't as good with snakes.

The nuclear option is suffocation. Mr. Pfister relies on an eight-page document from Airbus explaining the technique, which begins with a three-hour process to plug vents. Diagrams show how to build covers for an air valve and a sliding cockpit window. Next, staff get tanks of liquid carbon dioxide, vaporize it, and pump the aircraft with more than 2 tons of the gas over five hours to reach the concentration required to exterminate pests.

The CO2 is effective against almost any creature, the Airbus document says, except ticks, which "can close their trachea and virtually stop their metabolism," to avoid inhaling the gas. Cockroaches, the document warns, lay eggs before they die. The CO2 is non-toxic, so it leaves no residue harmful to humans.

"We fill it up like you fill a swimming pool," says Mr. Pfister. The whole procedure costs up to $11,500 for gas and labor. The gassed plane sits for many hours to kill anything onboard -- technicians want to ensure nothing could survive, since they might never find a corpse to verify death. "Sometimes we find it later, during heavy maintenance," says Mr. Pfister.

That's why Airbus rival Boeing Co. prefers hunting over gassing. Boeing's written policy warns that a "decaying animal may initiate localized corrosion of the airplane structure on contact." It also frowns on fumigating "because of the undesirable odors caused by the decaying bodies of pests located in inaccessible areas, as well as the attraction of flies and resulting maggots."

Feline Help

Ships, which faced rat problems long before airplanes existed, have used cats to catch rodents -- a much cheaper solution than fumigation. But that's not viable for airplanes. On Nov. 3, a CSA Czech Airlines flight from Frankfurt to Prague had to fly home empty, except for a stowaway cat that the crew had been unable to catch. The cat could have hurt wiring or equipment, says CSA spokeswoman Jitka Novotna. So the humans flew on another plane, while back in Prague, mechanics removed interior panels of the returned ATR-42 turboprop to find the cat. It was given to a home for strays.

Probably no number of cats would have helped Turkish Airlines with the problem it faced in April last year. A Turkish Airlines flight from Shanghai, China, arrived in Rome with 15 cages of rodents. An Italian inspector found them sleeping, apparently induced by altitude, said Turkish Airlines spokesman Recep Guvelioglu at the time. The inspector feared the animals were ill and sent them back on the same plane. En route, many escaped, probably because the inspector didn't close their cages well, Mr. Guvelioglu said.

The $180 million Airbus A340 was grounded for 20 days as staff searched unsuccessfully for the rodents and did an extensive maintenance check six months early. The tiny animals "cost us a lot in delays, jeopardized our plans and hurt our image," said Mr. Guvelioglu.