Imagine you're a pilot, and you're flying a Boeing 737 filled with more than 100 passengers. Suddenly, the gauges show that Engine No. 2 is in trouble, so you shut it off and start flying the plane on the other engine alone.
That's a troubling enough scenario. But what if it's worse than that: What if it turns out that a mechanic mixed up the wires in the cockpit, not long before you took off — so your gauges are reversed and you actually turned off the one good engine?
That scenario could have happened a few weeks ago on a US Airways flight, if an observant employee at the airline hadn't made a discovery: Mechanics who had just repaired the plane at the Aeroman repair company in El Salvador had, in fact, crossed the wires on two engine indicators in the cockpit. NPR obtained internal US Airways documents that describe the incident, and a senior company executive confirmed it.
Mistakes In El Salvador
This is just one of at least three troubling maintenance mistakes that mechanics in El Salvador have made recently while fixing US Airways planes. There could be more. But airlines and the Federal Aviation Administration don't make maintenance problems public. NPR first learned about these incidents from mechanics at Aeroman and at US Airways.
The Repair Trail
Mechanic reports, like this one obtained by NPR, reveal that a problem with wire connectors has occurred on more than one airplane.
The incidents raise questions about a growing practice at US airlines: Since an economic crisis began shaking the industry in 2002, most major airlines have stopped repairing and overhauling most of their own planes (American Airlines is an exception). Instead, they are sending the planes to be fixed for less money by private repair companies. The industry sends about 20 percent of its planes to be fixed at repair shops in developing countries, from El Salvador and Costa Rica to China — because labor rates there are cheapest.
Airlines can only use repair stations that the FAA has approved — including Aeroman. Industry executives and FAA officials say the maintenance work is just as safe as any in the U.S.
"I visited Aeroman about 11 months ago," says David Seymour, a senior vice president in charge of maintenance at US Airways. "I was very impressed with the facility, having been to a number of heavy-maintenance providers here in the U.S." He says Aeroman seems well organized and clean, and the mechanics appear well trained.
Executives at Aeroman refused NPR's repeated requests for interviews and a tour of their maintenance facility. But NPR talked with several of Aeroman's mechanics, who asked not to be named on the grounds that they might be fired for talking with a reporter. And they told troubling stories about what happens on Aeroman's shop floor. Their concerns echo problems that the inspector general at the U.S. Department of Transportation has also found at other foreign repair shops.
The Aeroman mechanics, who commonly earn about $5,000 to $10,000 per year, say they're proud of their work.
"It's a great responsibility," one says, sitting under a cactus along a narrow road near San Salvador. "Our supervisors are constantly highlighting to us that our job is not a game. The life of 200, 250 people that are flying depends on us."
Pressure To Hasten Repairs
But the mechanics say managers keep pressuring them to fix the planes faster. For instance, if there's rust on a metal beam, but it's just a little over tolerance, "the supervisor says, 'Oh, just leave it like that,' " the mechanic says, through an interpreter. " 'There's no need to repair it.' "
Outsourcing Aircraft Maintenance
Nine major air carriers reviewed by the FAA's inspector general sent 71 percent of their heavy airframe maintenance checks to outside repair stations in 2007, up from 34 percent in 2003. Foreign repair stations got 19 percent of these major maintenance jobs in 2007. The work includes complete teardowns of aircraft.
Source: FAA Inspector General, Aeronautical Repair Station Association
The FAA requires that mechanics fix the planes according to the airline manuals — whether they're in the U.S. or overseas. But the mechanics at Aeroman say their supervisors often say that takes too much time.
One mechanic says that just a few days earlier, he and his colleagues were replacing a kind of rivet, commonly called a Hi-Lok, along the fuselage. The airline's manual said they should use a "shear" Hi-Lok that's carefully engineered to withstand a specific amount of pressure on a specific part of the plane. But the mechanic says Aeroman didn't have the right Hi-Loks on hand, so the supervisor told them to use "tension" Hi-Loks that weren't approved for that repair.
The mechanic says he resisted, because the wrong Hi-Loks "would cause, actually, a crack in the fuselage when there is turbulence." When the supervisor pressured him to use the incorrect part anyway, "I told him no, because the manual does not allow me to do that," he says. But the supervisor ordered him "to go ahead and install it, because we were in a hurry to turn around the airplane."
Another mechanic ticked off other problems at Aeroman. Some employees don't store glues at the required temperatures, he says. That means the glues could fail — which potentially means that parts of the airplane could fall apart.
And this mechanic says some workers can't even read the airlines' repair manuals. The manuals are written in English, but some mechanics at Aeroman can't read English — including him. So, the mechanic says, "you have to ask for help [from] another colleague. And in my case I ask for help, often." The problem is mechanics are under so much pressure to finish the repairs that they don't have much time to coach their colleagues.
FAA Inspections: No Surprise
In theory, FAA inspectors should catch these problems. The FAA is supposed to inspect every repair shop that fixes U.S. airplanes, in the U.S. and overseas. But the mechanics at Aeroman say FAA inspections are a joke, because the inspectors always tell management at Aeroman when they are going to show up — they don't do surprise inspections.
"FAA inspectors always tell them, 'I'm going to be there on this date,' " a mechanic says. "And obviously, logically, Aeroman will do everything it can to have everything ready."
That means mechanics put the glues away in the proper temperature-controlled storage areas. They get rid of any unauthorized parts. "Then, the FAA won't ever find anything," the mechanic says.
Investigating Airline Repairs
This 2008 report by the inspector general at the Department of Transportation warned that FAA and industry inspectors are not monitoring airplane maintenance work properly.
The inspector general at the Transportation Department has discovered that flawed inspections at repair companies are a widespread problem. In fact, the inspector general's investigations have found that FAA inspectors never even showed up at some foreign repair stations, for as long as three to five years. Partly as a result, FAA officials don't have enough data to know whether Aeroman's work is better or worse than other repair companies.
Seymour of US Airways says he can't comment on the anecdotes that mechanics at Aeroman told NPR.
"I don't know the people you talked to," he says. "Does it raise concerns, the comments that you heard? You know, without me being able to validate that, I'm not sure that I can draw concern on anecdotal comments."
Seymour says he toured Aeroman in late 2008, and he found it as impressive as any repair company in the U.S.
"US Airways takes safety as our top priority," he says. "It's first and foremost in anything that we do, and we never sacrifice safety in any way, shape or form."
Basil Barimo, vice president of the Air Transport Association, an airline trade group, says the industry's safety record shows that foreign repair companies do excellent work.
The last time a U.S. airliner crashed because of maintenance mistakes was in 2003. The company that botched things up on that plane was based in the U.S.
Meanwhile, Barimo notes, the industry's use of foreign repair companies has been booming. He also says that Aeroman is one of the best repair companies in the world. But industry studies showing that, he says, are confidential.
Some aviation specialists and members of Congress say that as the industry cuts maintenance costs and other expenses, the margin of safety is getting thinner.
"That's a very scary thing," says Sen. Claire McCaskill (D-MO). She's pushing legislation in Congress that would require the FAA to be tougher on foreign repair companies.
"When you have a situation like this," McCaskill says, "where you're going to El Salvador because it's going to be a lot cheaper, and the company in El Salvador is going to make a lot more money if they can promise the planes out more quickly, then that is a dangerous stew that we are stirring."
In late September 2009, US Airways discovered another mistake at Aeroman: Mechanics mixed up the wires in the cockpit of another plane — the second case of crossed wiring in less than a week. Again, the gauges were connected to the wrong engines.
Seymour says the company sent a team to El Salvador to investigate what went wrong.