Southwest Airlines has released this video showing the changing of an engine on one of its Boeing 737 airliners. It's an interesting look at a routine operation, showing how the engine is actually relatively small beneath its cowling under the wing.
It actually looks simpler than changing the engine on some modern cars! At least the Southwest technicians have rather more room in which to work than the average auto mechanic . . .
Peter
The 737 is a rather old design, but I remember one of my engineering magazines having a feature on the CAD used by Boing, and how they would check every connection and bolt with a CAD model of an articulated human to verify that there was adequate space for servicing.
ReplyDeleteLike with a rally car, the speed with which regular required maintenance, wear-part-replacements, and repair of breakages can be done is directly related to owner income. Serviceability is a big part of the reason why nearly all of the world's low-cost airlines have standardized on the 737.
I read somewhere, a long time ago, that the GE J47 &J73 engines in an F-86D Sabrejet could be completely swapped out in just a couple of hours due to the unique desigh (for the time) where the plane's airframe could literally be disassemble in to two halves by removing a number of bolts around the mid-section.
ReplyDeleteBTDT
ReplyDeleteThere was this one time...
I'm an AME (Aerospace Maintenance Engineer) the Canadian equivalent of an A&P mechanic. This is normal on a passenger liner, they are engineered so that engines and other LRUs (Line Replacable Units) are quick to change as airplanes don't make money on the ground. There is a step by step procedure in the manual several pages long and every fastener and pipe has a specific torque. Curiously, I did not see any sort of procedural checksheet being followed.
ReplyDeleteThe ground support equipment such as the lifting yoke, the sling, chain hoist, dollies, etc are all specific to this airplane and engine model.
At 1:50 you can see the load gauge between the chain fall and the engine. The gauge is monitored constantly; if the load suddenly rises the engine is misaligned with the mount and is binding. Forcing it into to position will damage the mount, you have to re-align the engine or lower it and try again.
Fighter jet engines can be changed in as little as 15 minutes, by the way.
Al_in_Ottawa
Interesting video. Pity about the over loud "music".
ReplyDeleteYeah, the lack of anyone using torque wrenches might appear odd, but my assumption is that they weren't in any of the time-lapse shots intentionally.
ReplyDeleteWhen I was working on them, corporate instructed us to answer the FAA guys question with "What the manual says the torque spec is!"
And it sure makes it easier and faster to have all the specialized tools and fixtures already laid out for the job!