We hadn’t much considered the maintenance of airliners flying to and from Hawaii until two things caught our attention: 14 Hawaii flight diversions and a pilot’s mention of aircraft maintenance outside the USA. Safety on Hawaii flights takes on a whole different meaning when the nearest place to land can be up to 3 hours away.
Fourteen Hawaii flight diversions – most appear mechanical.
While airliners have redundant systems, and we also have stringent ETOPS on the world’s longest overwater flights to Hawaii to prevent these problems from becoming catastrophic, they are still concerning. The most recent diversion was for a serious trim motor malfunction which prevented the A330 airliner from traveling to Hawaii. This brings to mind the following question:
How are aircraft for Hawaii flights maintained?
John, a frequent commenter we believe to be an airline pilot, said, “SWA outsources Aircraft Heavy Maint Checks to El Salvador.” We’ve seen press releases here and there about overseas aircraft maintenance agreements, but as with diversions, we generally haven’t thought much about it before this. So we checked further into the maintenance of these planes, and John is correct.
Understanding the ABCD airliner maintenance check system.
Airlines call the routine maintenance inspections “checks,” and name them A, B, C, and D. While A and B checks are light checks, C and D are heavy checks. D checks, in particular, are inordinately time-consuming and multi-million dollar expensive and may take place at companies other than the airlines themselves.
A checks are performed every 200+ flights and require up to 70 person-hours of work. It varies by aircraft, flight cycles (take-offs/landings), and hours flown.
B checks are every 6+ months and require up to 180 person-hours of work. A and B checks can be combined.
C checks take place every 20+ months typically and require that a majority of the plane’s components be inspected. This aircraft will be out of service for up to 2 weeks. Up to 6,000 hours may be needed. Sometimes, a 3C check is done simultaneously, which looks for corrosion or specific “high-load” components of the plane (think Aloha 243). This may also be the time to do any interior upgrades.
D check. This is the biggie, specifically referred to as the “heavy maintenance visit.” It typically takes place every 6-10 years, and the entire plane is subject to inspection and overhaul.” Paint may also be removed to check the plane’s actual metal skin below. All wing, tail, flap, and rudder panels are unscrewed. Cables, bolts, bearings, and brackets are removed and inspected. Even the landing gear is taken apart and checked for possible cracks, leaks, and corrosion. Jet engines are removed as well. The interior, including seats, tables, bins, and side panels, is taken down to bare metal for inspection and then reassembled.
A D check can take as much as 50,000 person-hours to perform.
This takes place over two months out of service. It is a multi-million dollar undertaking, and planes are scheduled for these far in advance. It can also be the time to remove older planes from service to avoid the D check. Typically, only two to three D checks are done in an airliner’s lifetime.
Why is Hawaii aircraft heavy maintenance outsourced overseas?
In a word, cost. We’ve seen estimates on the cost of a D check being $1.5 to well over $5 million depending on the plane. And those numbers are probably relatively low.
Last year, Hawaiian Airlines signed an expanded airframe maintenance agreement with Singapore-based SIAEC. The company is doing heavy maintenance checks and painting for the company’s A330 widebody fleet. Hawaiian flies the planes some 13 hours to Singapore to be able to have the work done there rather than in the U.S.
Hawaiian Airlines said, “We are confident in our choice of SIAEC as a long-term provider and partner.”
Is such heavy overseas maintenance dangerous?
Most big U.S. airlines have moved D check maintenance overseas, where apparently few mechanics are FAA certified, and some may not be able to read or speak English. To our understanding, all of the technical manuals are in English only. FAA-certified mechanics, on the other hand, must have complete English skills. Mechanics in other countries do not necessarily have those skills.
We heard that less than 10% of foreign airline mechanics have English proficiency. And while the facilities themselves may be FAA certified, that does not mean that all or even most of their mechanics are.
Previous foreign maintenance nightmares.
First, an Airbus with a D check performed in Xiamen, China, at a facility used by U.S. airlines, had 30 screws missing from one of its wings and flew for five days before mechanics in Boston uncovered the problem. Another Air France plane with its D check in China was grounded when it was discovered that the plane’s paint was of the wrong type and flammable. And in another case, an Airbus had all toilets overflow and needed to divert on the first flight following a D check in China.
Also, a U.S. Airways (American Airlines now) 737 had to make an emergency landing when it was determined that the main cabin door started to fail when the El Salvador mechanics installed components backward.
Faulty maintenance work at overseas facilities is frequently found when subsequent safety work is done in the U.S.
Southwest heavy maintenance is in El Salvador.
We can confirm that Southwest does heavy maintenance at a facility in El Salvador. We’ve also been told that Delta may send them to Mexico, and United uses China. American Airlines is said to have the most extensive in-house heavy maintenance facility in the U.S.
The bottom line is that the foreign mechanics that do this hugely laborious and critical safety work make a fraction of what is paid to US-based, FAA-certified mechanics.
Aeroman, used by Southwest, has exploded into a huge complex in El Salvador with nearly two dozen production lines and many specialties.
Congress has expressed concerns, too, over the FAA’s lax oversight of these foreign facilities. “Report after report by successive DOT Inspectors General has revealed troubling deficiencies in FAA oversight of foreign repair stations that perform more and more critical safety work on US-registered aircraft,” said one senator.
SWA points to the good safety record of foreign repair stations, but at the same time, uses its mechanics to promptly inspect aircraft shortly after return to the U.S.