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When do aircraft engine RTS?

Posted: Tue Jul 07, 2020 1:15 pm
by Diehard
Hi all, can I ask, normally under what circumstances do aircraft engine Return to Service to the MRO shop?

Best regards

Re: When do aircraft engine RTS?

Posted: Tue Jul 07, 2020 4:15 pm
by flybaurlax
I'm not sure I follow your question. Can you narrow down specifically what you're looking for?

Re: When do aircraft engine RTS?

Posted: Tue Jul 07, 2020 7:08 pm
by Dalmd88
What kind of MRO? An engine shop that does a engine shop visit? That usually means an engine run in a test cell. The serviceability tag usually follows a successful test. Or if no test cell run is required when they finish building the motor back up and the paperwork is cleared. It might have a conditional release stating it needs an on wing run for leaks though.

An MRO that does airframe work? The engines are serviceable at the same time the rest of the airplane is made serviceable by the shop. Once all the test are done and the paperwork is cleared.

Technically they are serviceable as soon as any required work is completed. When I worked heavy check our engines would be robbed to support in service aircraft quite often. Typically we would do the 'zero time check' in the first couple of days of the month long visit. That was the filters and such. The engine itself usually did not have many inspection write ups so any that did occur they could be cleared quickly and the engine could be used on an in service plane if needed.

Re: When do aircraft engine RTS?

Posted: Wed Jul 08, 2020 3:12 am
by Diehard
Hi flybaurlax, sorry if I am unclear. I just joined a MRO shop as a supporting role. Sometimes, the customers wants to send their aircraft engine back to us as "RTS". What I understand is that these engines have been overhauled before and left the shop. But it is now back as "RTS". So I am not sure if the engines have already been overhauled and left shop, why and under what circumstances do these customers want to RTS as it cost them quite a lot of money. How are the workscope of RTS different from normal engine shop visit?

Hi Dalmd88, yes it its an aircraft engine shop that does a engine shop visit (not for airframe). very thankful for the valuable information.

Re: When do aircraft engine RTS?

Posted: Wed Jul 08, 2020 1:19 pm
by battlegroup62
Diehard wrote:
Sometimes, the customers wants to send their aircraft engine back to us as "RTS". What I understand is that these engines have been overhauled before and left the shop. But it is now back as "RTS". So I am not sure if the engines have already been overhauled and left shop, why and under what circumstances do these customers want to RTS as it cost them quite a lot of money. How are the workscope of RTS different from normal engine shop visit?


If the engine you have received back is the same one that was sent out as overhauled RTS could mean Return to Stock and not Return to Service. They would RTS the engine if they ordered it but did not end up replacing the engine and do not wish to pay for the engine they are not using.

If RTS does mean Return to Service it would mean the engine likely failed and needs the be disassembled, inspected, repaired,reassembled, and tested in order to be airworthy again.

Re: When do aircraft engine RTS?

Posted: Thu Jul 09, 2020 3:14 am
by Diehard
Hi battlegroup62, thanks very much for the information! appreciate it.

Re: When do aircraft engine RTS?

Posted: Thu Jul 09, 2020 2:33 pm
by Dalmd88
It could also be a 'green time' engine. That is an engine that has been in service on an airplane and removed with life left before overhaul. Their RTS request may be just do what is required to prepare the engine for a new install. We would call it a Zero Time check in my airline. Suspect it would be a full internal boro inspection. External general visual inspection. change all time limited filters and such (this is the zero time part). Likely a test cell run to make sure it meets performance spec and leak checks.

Why would you do this check? It could be a purchased used engine that has to be added to the airlines' system. The engine may also have some changes the airline wants to standardize the engine with the rest of the fleet. The could be internal that require a short shop visit.

For the best answer to your question go ask some one involved one of these checks. The lead tech running the visit would most likely be willing to chat for a few minutes. Also I would guess the workscope for one of these visits is published on an internal website. You may not have access due to your job classification, but you never know. I know at Delta, workscopes for all of our engine visits are internally published for all Tech Ops employees. A lot of people have to interact with the visit.

Re: When do aircraft engine RTS?

Posted: Fri Jul 10, 2020 6:37 am
by Diehard
Hi Dalmd88, thanks for very much for the information! I have heard the tech team talking about Zero Time check before. Now I know what it is about! Its also an excellent idea to read the workscope, I am not have access as I am only support role but I will try to see if I can read of the RTS workscope. Thank you very much!!