how do u overhaul a jet engine?

Question

this is for my AMT class

Answer 1

I always wondered how they did it. When i was stationed at a base in Oklahoma, i found out one way they can accomplish an overhaul.

It all starts with a disassembler. They placed the engine in a special rack, compressor portion down, that had a four sided catwalk mounted to move up and down. Starting with the top part or the turbine, they disassemble it. since an engine is basically a long spindle or stem with a lot of disks that hold different sized blades placed on it, its kinda like unstacking a bunch of poker chips: removing the top one, then the next, and so on. the elevator moves down with the process.

These parts are then cleaned, examined, and replaced or put back into tolerances. then, once all the parts are back in the shop, they start the stacking process, with the compressor parts first, till the engines rebuilt.

you have to see it done to believe it.

Answer 2

Years ago jet engines were usually overhauled at the end so many hours of operation. The spec might be a major overhaul every 300 operating hours. The major overhaul was basically disassemble, inspect and repair as necessary, assemble and then test.

This was an expensive procedure that was often not required if there was nothing wrong with the engine. In addition, we occasionally damaged a perfectly good jet engines during the disassembly. As the reliability dramatically improved over the years, the overhaul based on hours was dropped.

The airlines were the first to implement “fly to fail” which isn’t as drastic as it sounds. Basically it became fly the engine until there is an indication of a problem or abnormal wear. For example, during operation, below normal thrust, vibration, excessive EGT (exhaust gas temperatures), or a fire warning light, might prompt a major overhaul.

One way to check for wear without removing the engine from the airframe is to conduct a periodic spectrographic analysis of the oil. Depending on metals found in the oil, and trends over time, it’s possible to determine when the engine requires overhaul and even which section requires work. Since engines consist of several modules it’s even possible to disassembly only a portion of the engine, repair the affected module, reassemble, test and return the engine to service.

So the next time your on an airliner and one of the engines quits, don’t worry, it flew to fail!

Answer 3

Well it depends on a lot of things. In the Air Force we would only overhaul an engine if it had flown a certain number of hours, and then there were different levels of the overhaul process. Mostly though the manufacturer of the engne will give you all that information. Now how is it overhauled....like I said depending on the level of service needed you might take a few minor components off and put new ones in their place, and then put the engine back in the plane. At another level you may take of more minor parts and 1 or 2 major parts swap them out with new parts and then put the engine back in. Again though these processes are determined by the manufacturer. You don't need to clean it but you can if you want to.

Answer 4

Maybe the answer you are looking for is what work has to be performed in order for an engine to be "overhauled". For the FAA, that definition can be found in 14 CFR 43.2.

43.2 Records of overhaul and rebuilding.
(a) No person may describe in any required maintenance entry or form an aircraft, airframe, aircraft engine, propeller, appliance, or component part as being overhauled unless—

(1) Using methods, techniques, and practices acceptable to the Administrator, it has been disassembled, cleaned, inspected, repaired as necessary, and reassembled; and

(2) It has been tested in accordance with approved standards and technical data, or in accordance with current standards and technical data accepteble to the Administrator, which have been developed and documented by the holder of the type certificate, supplemental type certificate, or a material, part, process, or applicance approval under §21.305 of this chapter.

Answer 5

You don't. Unless your working with an A and P license under the supervision of an A and I at an authorized fixed base operator. Or at the original manufacturer, in which case it is called "Remanufacure" or rebuilt. Check your FARS. It is not exactly the same as pulling the engine from a fifteen to anything year old car, and doing it under a shade tree.

Answer 6

I imagine the same way you overhaul ANY engine, Take it apart, clean, and replace any damaged parts. Put back together.

Answer 7

Fast and dirty: Take it apart. Clean all parts. Inspect all parts and repair or replace those that are out of tolerance. Reassemble. Test.

Answer 8

You cant be serious... you want someone to tell you how.. do you know how thick the Technical Manuals are dude....cmon now... thats why you are in class....

Answer 9

send it to an FAA Repair Station like the one I work at...