FedEx Jet Crash: Wind Shear Eyed As Cause

TOKYO — Wind shear may have caused the crash of a FedEx jet that cartwheeled on the runway at Tokyo's main international airport and burst into a fireball, investigators said Monday, but experts noted that the model was notoriously difficult to land.

The American pilot and co-pilot _ the only two people on board _ were killed when the MD-11 cargo plane bounced on its landing at Tokyo's Narita international airport, slammed onto the runway and tipped onto its side before exploding into flames.

Kazuhito Tanakajima, an aviation safety official at the Transport Ministry, said the crash may have been the result of "wind shear," sudden changes in wind that can lift or smash an aircraft into the ground during landing.

But Tanakajima said the wind speed alone was not necessarily dangerous. He said there was headwind of about 45 miles per hour (72 kilometers per hour), and a crosswind of about 7 miles per hour.

Wind shear is a sudden change in the speed and direction of the wind, and happens relatively frequently. But a dangerous localized form _ called a microburst _ can cause planes to lose airspeed suddenly and or lift abruptly if a headwind suddenly changes to a tail wind during takeoff or landing, said Patrick Smith, a Boston based pilot and aviation analyst.

During the 1970s and 1980s, microbursts were blamed for a number of aviation disasters in the United States that helped usher in a new generation of wind shear detection technology.

Smith described a wind speed of 45 mph as unusually powerful.

"It is possible that shears from these gusts, together with known instability issues of the MD-11, led to the accident."

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He said the aircraft is unusually sensitive on the controls but the downside is a tendency for pilots to over-control during a bounced or otherwise unstable landing, which in severe cases can lead to a total loss of control.

The MD-11 has had no fatal crashes since 1999 and was largely retired from passenger service because of the introduction of more economical planes.

Tomoki Kuwano, a former Japan Airlines pilot and aviation expert, said the MD-11 can be hard to land.

"In the past, the MD-11 has a record of landing failure," he said. "And when that happens it often flips over."

In 1999, an MD-11 flipped over and burst into flames, killing three people during a crash landing in a storm in Hong Kong. And in 1997 one of the planes landed hard, flipped and caught fire while landing in Newark, N.J.

Monday's was the first deadly crash at Narita _ the main air hub for international flights to Tokyo _ since the airport opened in 1978. According to the U.S. Federal Aviation Administration, pilot Kevin Kyle Mosley, 54, of Hillsboro, Ore., and co-pilot Anthony Stephen Pino, 49, of San Antonio, Texas _ were killed as they landed the flight from Guangzhou, China.

FedEx, which just last month opened its Asian hub in Guangzhou, said it was investigating the cause of the accident.

"We will continue to work closely with the applicable authorities as we seek to determine the cause for this tragic incident," the company said in a statement.

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Associated Press writers Tomoko Hosaka, Shino Yuasa, Jay Alabaster, Mari Yamaguchi and Slobodan Lekic in Brussels contributed to this report.

Comments

[RationalDubSteppa]

There was a major reason why Airline Companies ditched the MD11 and it was because of the small tail that made it really hard to stabilize during wind shears. But to add insult to injury the MD11 has very sensitive controls and an engaging autopilot mode that kicks in and does not necessarily disengage when wind shears happen during approach(which can be very very dangerous). The MD11 was also plagued with numerous software issues(that caused the over controlling mentioned in the article) regarding readings from the instruments, in essence the MD11 had a reputation of exaggerating readings. These aircraft should be seriously overhauled or just plain dismissed.

[MajorKong]

The cargo carriers like the MD-11 for one reason. It "bulks out" at the same time that it "grosses out".

In other words, if you fill it with cargo, it will be at or near its max gross weight. A 747 hits its max weight with room to spare, meaning you're burning fuel to carry empty space across the ocean.

[dreadpirateroberts]

The "major" reason the MD11 was replaced in the airline industry was economical, not safety. It has been replaced by two engine widebody aircraft such as the 777 and 767 that are simply more efficient to operate. By the way, if the airlines thought they could make a profit flying the Hindenburg, they would do it. Cost is the ultimate motivator in fleet decisions.

[RationalDubSteppa]

Your right about the fuel efficiency problems, I forgot to mention that. Indeed the MD11 was mired with significant range problems that other wide-body aircraft did not have. However I must respectfully disagree on your point on why airliners dropped it. Range was definitely a huge consideration but a lot of airline companies where receiving numerous complaints on the handling of the MD11 and the software as well. I believe it was a combination of all o f those factors that lead airline companies to drop the MD11. But thanks for pointing out the range issue.

[mawrm]

It's not an issue with the aircraft, it's the windshear. Landing in a 45 mph is dangerous because as you approach the ground, you lose that headwind and sink like a rock. The problem is it's difficult to predict where the wind speed shift will occur . The risk is they would have had to have come in "hot" to compensate for the shift which also can lead to a disastrous landing situation. To make matters worse, In many aircraft when you enter the flare attitude, elevator authority is diminished. Once you hit hard, it sets up an oscillation which often gets aggravated with PIO (Pilot Induced Oscillation). In smaller aircraft, you can apply full power and get out of it but on the bigger jets, the engines take too long to spool up. My prayers for the crew and deepest sympathies for their families.

[grg99999]

DC-10's and MD-11's have made over 40 million safe landings.

No plane design gets a flight certificate unless it meets very stringent requirements regarding safety of flight, including takeoff and landing performance.

If you want to talk about dangerous designs, look at all those regional jets with supercritical wings, where one credit-card thickness of frost on the wings can make them spin into the ground. About one a year lately. Another one just last month.

[SwingingFromCenter]

There's a reason why they're called "Douglas De.ath Tubes".

[RationalDubSteppa]

Indeed! The software pitfalls in the aircraft alone is enough to make anyone cringe.