Singapore MRO Screws Up Left Side and Right Side

[Thermal Image]

http://www.japantimes.co.jp/cgi-bin/getarticle.pl5?nn20051222a3.htm


JAL jet flew half year with engines on the wrong sides

Japan Airlines flew a Boeing jumbo jet for seven months without realizing its port and starboard outer engines had been switched to the wrong sides during maintenance in Singapore in February, airline officials admitted Wednesday.

Some of the engine components are required to be inspected every 650 flights, but the mistake resulted in one of the engines going through 850 flights before being examined.

Reversing engine locations causes air to flow toward the fuselage instead of away from it during reverse thrust when slowing after landing. However, it does not create any difference during normal thrust and thus poses no safety problems in flight, the officials said.

The Land, Infrastructure and Transport Ministry instructed the airline to take preventive measures anyway.

In February, JAL commissioned ST Aviation Services Co. Pte Ltd. in Singapore to overhaul the four-engine Boeing 747. The plane resumed service in April.

It wasn't until a regular checkup in November that the engine switch was discovered, the carrier said.

JAL officials said they will revise in-house procedures to ensure plane inspections are conducted after outsourced maintenance work. The current policy only calls for document checks following maintenance.

The Japan Times: Dec. 22, 2005

[BlueEagle]

Apparently all the engines are interchangeable on all four positions BUT there are some adjustments to be made to the thrust reverser system, depending on which side and whether inner or outer. More here. (http://www.pprune.org/forums/showthread.php?s=&threadid=203197)

[Thermal Image]

Yes you are correct that it's not a disaster.

At the same time while no real harm came out of it, it does reveal some really slipshod work practices, and it is astonishing that the error was not trapped by cross checks and inspections.

Sort of like having a shade tree mechanic overhaul your engine, reassemble it and discover a whole bucketful of nuts and bolts left over.

[sgrookie]

When I read about it in the jet blast forum, I was hoping that its not really Singapore, but now the industry people might not have as much faith in our maintenance crew. I'm quite disappointed, really... SG's credibility might be damaged :(

& regarding the shade tree mechanic? I've had a couple of experiences with such so called mechanics... the experience is not good at all... :mad:

[Blacksheep]

Actually, its nothing like a shade tree mechanic with bits left over. How they managed to fit the Nos 1 & 4 engines in the Nos 4 and 1 positions is a human factors incident. Though the engines are physically interchangeable, they do have serial numbers and those serial numbers should be on every page of the work sheets.

The non-technical may miss the point, but the real issue here is the overrun on a scheduled maintenance inspection. Assuming they actually did the inspection at the scheduled interval, but on the wrong engine, JAL must also have missed the serial number mis-match - for a second time.

[SIDSTAR]

Who's surprised at this? SIN maintenance must be the worst I've come across in first-world country. And the worst part is that they really fancy themselves as the experts.