Air carrier inspector reported they were notified that safety hardware was found missing on the front engine mount after they signed off the final inspection of the complete engine installation.

Narrative

I completed a last 'clear to close' inspection on the #2 engine after an engine change. It was discovered later that a few of the safety hardware on the front engine mount were missing. I am told that it left ZZZ and that a mechanic found self-disclosed the hazardous situation; ZZZ1 verified that the front engine mount hardware were missing their safeties.I cannot be fully clear now what happened since almost a month has elapsed from the happenstance; but I will attempt to provide as much information as I can in order to give insight of the occurrence from my point of view.The engine change job card lasts multiple shifts which is typical here in ZZZ. I did not oversee the safeties on the mounts; but at my step I could have seen that they were not completed; and I did not notice them. I will take this opportunity to introspect how this came to happen and then also offer what might have helped me not overlook them so we can also improve as an organization and as an industry.At that step I would have inherited a mounted engine with its safeties; and we would have been moving on to all the connections in that phase. After all the connections are made; and getting ready to run and test the engine; I need to perform a 'Clear to Close' step as I call it. In this narrative; I both invite you to my introspection and if you are interested; I will further give ideas of how I and others cannot make this mistake in the future.At 'Clear to Close' as I call it or step XX of Job Card XXXXXXXXXXX which reads 'Accomplish A Final Installation Inspection of the Engine' I typically go over the whole engine inspecting it for any last-minute repairs. I usually do find things wrong; actually. It is actually an unfortunate step because it is kind of a 'bearer of bad news' step. Let me explain that. Everyone is finished and delivering visual progress to management of a connected engine; ready to test but routinely I find small things and sometimes time-consuming items that delay moving the plane along to revenue ops.Please understand that in the process of installing the engine; the mechanics are all over that engine; pylon and cowlings and I do find things that delay the process routinely and it is inconvenient timing. Examples might be wirers that have opportunity to chafe or dislodged; delaminated seals which may have come undone during the process by rubbing up against them. As they say; 'hangar rash;' etc. I call attention to this to give insight how I am thinking during this step. So; at that step I take the opportunity with all others being away from the engine to see that we are delivering a pristine product. There are times though at Clear to Close; I am 'the bearer of bad news.' I truly wish to get the plane to revenue as quickly as possible. Fly them is how we all make a living but only as long as it is safe and ready. Unfortunately; that step comes with bad timing from other's points of view; but I do find things during that interval.In my opinion; it is really good and safe that this step is written so ambiguously. It is a good thing because it is here that the engine is getting my blessing; so to speak. I am trying to invite you; the reader; how I observed my role in this step and how I am thinking at this point. In this I hope to convey the breakdown of why I missed the safeties as I estimate what happened.At that point I would have been involved in looking over or all the connections during the entire shift so I would have overseen all the connections firsthand; not the mounting but system connections. Though I do not get complacent at the end of that process; at 'Clear to Close' since I saw all those connections firsthand; my mind is to look over the whole of 'the engine' but interesting to me is that I neglected to think of the mounts at this step. I am aware of what could happen if the engine peeled away from the wing and thank God someone self-disclosed the condition. How serious this was; is not lost on me but I am trying to examine how I failed so I can improve. Also; if I can help the operation that I might be an example of what not to do; I am happy to do so. What follows is; what I thought happened; what I personally can do to improve; and also if welcomed to; to take the opportunity to examine what could have helped me externally.Since it is a multishift undertaking with many hands in the process; I sort of group the whole of it in large groupings or events. This is good for production; but it would seem that it added to my forgetfulness of looking at the mounts. Let me give a few examples of those 'Large Steps or events' I grouped together in my mind: 1. Examining the new part's effectivity before moving forward. 2. Hoisting and mounting. 3. Attaching systems of the engine to the wing.Later as well as having learned my lesson; I want to take an opportunity to say what might be changed to help me and others not make the same mistake. Please observe my humility in this. I am trying to both step away from emotions to be objective but still engage with them like guilt; shame and surprise and remain focused on improving and what I can learn from it. It might help to understand that as a Catholic and while in confession; I am practiced at handling the guilt of sin but then moving forward with better insight. At least this is my experience with the sacrament and life in general if the reader can relate. This is how I am approaching this so please do not confuse my matter-of-fact narrative with lack of remorse. I am glad that it wasn't as serious as it could have been. Even if I am a spectacle among my peers for this failure; if good fruit could come from this; I am happy to be the example.As I said above about the happenstance; I feel like I psychologically grouped the 'Clear to Close' step with all the connection tasks and in my mind; I grouped the hoisting and mounting as being together and separate. Psychologically; I thought of the engine being mounted as finished and 'in the past' and as a 'given.' It's somewhat like having faith in a landing gear; its processes and its equipment as being installed and working while working on a wheel assembly specifically. The engine change being a long job; I compartmentalized the mounts away from the attaching of all the systems. I believe this is how I overlooked them; and I will not be doing that going forward in this step. In this step I would have been able to observe the adverse configuration. I just did not think of it for compartmentalizing it away as in 'hoisting and mounting.'During 'Clear to Close' I do look over the engine more than a cursory inspection. For instance; I typically look for wires and other external elements which may have gotten disturbed during all the work and think this is essential and to be taken very seriously. The mechanics are like busy beavers 'next stepping' through the processes; so it is good for QC (Quality Control) to be slow and observant at the end of that. This step is the 'one over' of everything that is not specifically called out in the work card. Please keep in mind that during 'The Connection Phase;' I wouldn't have been combing over the entire engine with all the connection steps. I would have been more acutely focused on those individual steps. It is my role to be focused on those steps at those points in time; but I also would be going back over all that I had just previously observed; and I do during Clear to Close. This however might facilitate a hyperfocus on the engine and its system connections and not necessarily the whole job like mounting. In the cockpit while doing run inspections we revisit the part effectivity separately for instance which was a step all the way at the beginning; but it is called out specifically. It is possible I may have looked right near the mounts and not noticed the safeties for having been 'In this mode.' Even though I had just been involved in observing all those areas; I still see to it that I look over everything; yet I missed the mounts! It is for this that I have been curious how I could have looked past them and this is what I have come up with.On Clear to Close I look the engine over very closely during this step but again; with how we typically do engine changes; the mounting can almost seem like a whole other job if one neglects to actively think about it. It is a 'hung engine' and now I am looking at the a 'connected engine.' This is where I see my mistake as I psychologically examine my conscience.In short; I missed it because I thought it was done; and we were already moved past them and also because I grouped Clear to Close with attaching systems in my mind away from 'hoisting and mounting.' Going forward; I will now look at the Clear to Close step as completely separate and autonomous of other 'Large Mental Steps' and remember to be critical of the whole engine change not just a hyperfocus on a large process part or event. Again; Clear to Close to me is a very important step and it was also on that night as well. I really look at everything closely and even delay delivery at times for that step; but I seem to have had tunnel vision after having just observed all the connections in and around the engine to have simultaneously forgotten the mounts.This is my account away from the incident and what I could come up with why this happened from my involvement and point of view and work habits.Suggestions: 1. The block that I stamped is very non-descript. It may be helpful to include broad areas to look over to serve as reminders of what to look out for. I think a concise list would be best. Presumably; all the little tasks are written about exhaustively but at Clear to Close a good laundry list would be very helpful. As it stands ambiguous; that is good but a list of hot items would be good here. Specifics like engine mounts would be a great reminder. I'd write it like: a. IDG oi.l b. Engine mount safeties. c. Disturbed wiring. d. Etc... e. Etc...I would not reinvent the entire paperwork in this step; but I would make a sort of grouping of large events that typically happen on a shift. Then I would not tick away tasks but just call out things to look out for. I think you want this step to be broad and ambiguous. A list is good but the step in my estimation is meant to be broad and free to really observe anything that might pop out. It has strength that way so as not to be rigid. A punch list of reminders might have caused me to get out of my head and look at the whole of the engine change instead of the connection phase. Clear to Close typically falls at the end of the shift; readying the plane to be run so I think this is why I grouped it in with the connection phase and not also the mounting phase.If I were rewriting the step I would write it from two scopes. First; I would try to think of the engine change in large events or steps and list them to the inspector so he may think of observing all those processes individually. Then I would secondarily list hot items to look for. I would be happy to convene with my peers all that they pay close attention to in this step if I can be of any assistance. 2. What I can do going forward personally is what I am already doing. I can and already remind myself that I cannot trust that all the steps that are completed ahead of my steps as being completed correctly. I can approach the task; if handed down to me as needing to be gone over as if it were my work. I obviously cannot redo a turnover; but I need to be more vigilant to see that prior work was completed correctly as best as possible. 3. I can keep in mind not to get tunnel visioned. Clear to close involves looking over all that can be seen as well as auditing that all the tasks are finished.I hope all that I wrote helps the operation and I am deeply sorry for not being as thorough as I should have been. Please allow me to help if you feel like