Posted on 05/15/2004 5:30:08 PM PDT by Indie
SEATTLE -- KIRO Team 7 Investigators discover cracks, corrosion and weakened metal hidden inside a growing number of Boeing passenger jets.
The problems lie along structural seams called lap joints. A fuselage is designed with overlapping sheets of metal riveted together. We uncovered at least 28 different warnings regarding flaws or defects.
In 2002, a China Airlines jet plummeted into the water, killing 225 passengers.
Flight Standards Information Bulletin for Airworthiness (HTML VERSION)
Flight Standards Information Bulletin for Airworthiness (Microsoft Word Version)
Fourteen years earlier, an Aloha Airlines 737 opened up like a sardine can, killing one person and injuring eight more.
KIRO 7 Eyewitness News Investigative Reporter Chris Halsne discovers a big new problem for Boeing, centered on "lap-joint metal fatigue".
The problem is called "scoring". During assembly, workers lay a bead of sealant along this lap joint. It makes the jet more aerodynamic.
A year or two flying you around and many jets have to get repainted. Powerful chemical strippers melt the sealant, so some maintenance crews have been putting on caulk then, according to the Federal Aviation Administration, have been cutting away the excess with a box cutter. That can ruin the integrity of the metal along the entire aircraft lap joint.
The FAA recently grounded three passenger jets due to "scribe marks" and has identified 32 more Boeing planes with damaging box cutter-type cuts along the lap joint.
"When we found this, we jumped on it right away," said FAA spokesperson Mike Fergus.
Fergus says they have no idea yet how many more jets are affected by scoring.
"With the contraction and expansion of thousands of flight hours, the scratch has the potential, not a guarantee, the potential of turning into a crack. That in turn may have safety factor. That's our issue. If it's safety, we're interested," Fergus said.
Scoring of some lap joints is just the latest chapter in Boeing's long battle with the design and maintenance of its riveted seams.
"With that type of structure, whatever is occurring between the two sheets is not readily visible," said Earl Brown, a certified jet engine and airframe mechanic.
Brown says the FAA has been warning airlines to inspect -- and re-inspect often -- the lap joints of thousands of still-operating older model Boeing jets.
"If we can catch a problem when it's still just a crack and fix it, then we don't have to worry about something coming apart, breaking. The potential for breaking is there if a crack develops. It's pretty much inherent in the design of the airplane and the materials used," Brown said.
The scoring issue has been kept quiet until now, but other huge maintenance nightmares include hundreds of previously "patched" or repaired planes.
An Airworthiness Directive says new inspections are necessary to find "premature cracking of certain lap joints, which could result in rapid decompression."
Spotting fatigue in the lap joints on the outside of an aircraft, through the paint, is nearly impossible. So here's what the airlines have to do: They have to bring the jet into a hanger and gut the interior. That can cost more than $1 million.
The super-high cost of that "D-check" inspection is hardly an incentive for airlines to look really hard for trouble spots. For example, KIRO Team 7 Investigators uncovered an Aviation Safety Report filed by a mechanic last year. He reported his company ignored a potentially deadly safety problem saying, "A B737-200 had water leaking on passengers and inspectors found all fuselage lap joints leaking excessively."
Despite that, the mechanic says the supervisor "told me to get off the ACFT and not to check any laps. This ACFT had to go."
Independent aviation robotics engineer Henry Seemann doesn't look at a Boeing 737 like the rest of us.
We view them as a whole. He sees them in tiny parts, up close, one rivet at a time. And what he sees should make all of us a little nervous: cascading metal cracks, loose shear clips, corroded lap joints and tiny cuts in the metal.
Halsne: "Are there times when you walk up to a plane and think, 'I don't know about this one?'" Seemann: "Yes, I've had my moments of certain airplanes when I've looked at them and actually booked a different flight."
Seemann invented a machine, currently used by Boeing itself, that automatically inspects lap joints. The robot could save the industry billions in early maintenance because it takes just a few days to computer map and analyze lap joint flaws. Current methods take a month.
Despite the potential cost savings some airlines are telling Henry don't get that thing near our passenger jets.
"There's a requirement that if you know something is wrong with your airplane, you're supposed to fix it. It's a moral thing," Seemann said. "Some are afraid of that -- that their fleet is kind of old and we're going to inspect their planes and we're going to put a big red "x" on them."
The Federal Aviation Administration confirms this robot design is in the final stages of approval. It could revolutionize the way we spot catastrophic metal failures -- before a serious accident.
Boeing refused our repeated requests for an on-camera interview about "scoring" and other lap joint issues, but did provide us with some background on how it's working hard to fix the problems.
We called Boeing again this week for a statement. While they still won't comment on past metal fatigue issues, they did say design improvements on their new line of 7E7's should take care of future problems.
Copyright 2004 by KIROTV.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
I guess Bondo wouldn't help a whole lot with this.
Look at how many 707's, 727's, DC-8's, and DC-9's are still flying after 30-40+ years of service.
Heck there are DC-3's still flying.
Exactly. Another example, though not a passenger aircraft, is the B-52.
those pesky box cutters again!
Yeah, that's correct and I feel stupid for not saying it. DOH! :)
Amen to that. It's a treat, anymore, to see one of those venerable 4-engine monsters fly over... All the other planes are pretty much the same - blah.
Regards,
Regards,
I dont look back at the 40 years of service that one plane might have performed. I worry about the upcoming 41st year.
It's not a Boeing issue, it's a box-cutter issue. Obviously you don't take a knife to an airplane wing.
This story couldn't come at a worse time, however. Last month's balance of payments deficit shot up because of massive imports from Airbus Industries.
The youngest B-52 is at least 40 years old! Amazing!
A total of 744 B-52s were built with the last, a B-52H, delivered in October 1962.
I don't fly, but if I had to it would be 737-600+ or 777 only now. I want something brand new.
I've seen this air-blown airhead. I won't talk about (IMHO) he couldn't even discover, but to "discover" something like this -- naah, somebody told him.
But then the self-promotional hype of Seattle television "news" is so awful I quit watching it sometime in back in the 80s. The early 80s... (i.e. just after I moved there).
Hmmm was the study done by the Airbus...
I love how they are Boeing jets to KIRO, even the ones that were sold 30 years ago! Boeing hasn't made 737-200s for a long time!
Once the airplane is sold to an airline, it is the airline's responsibility to maintain it. Boeing does advise the airlines on how to maintain the aircraft and problems to look out for, but if the airline doesn't follow federally-prescribed and audited maintenance, it is not Boeing's fault when that airplane falls apart.
Is it Ford's fault that the floor of the trunk of my 1972 Maverick rusted through because I failed to check and maintain the seals on a 30+ year-old car and to make sure water that got in didn't sit there?
Having said all that, for some of us the worry over the "cost measures" taken by companies who have more concern over the "bottom line" than over human life - which, BTW, has been considerably cheapened over the last 50 years - exceeds concern over the airworthiness of older aircraft which were built in a different era with a different mindset.
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