How are Aircraft Maintenance Done?

In the case of a plane or helicopter accident, it comes to mind how such meticulous mechanisms can fall and the first question is, "Was there a negligence in its maintenance?" is happening.
aircraft maintenance is a job that puts a lot of responsibility on the builder
"Is it maintained, is it so, but is it cared like this?" I am writing these lines in order to eliminate ignorance in style.

aircraft maintenance business is a very general concept. sometimes it never refers to a single operation, in contrast to the erroneous logic we see in the media.

maintenance of airplanes and helicopters is done according to the schedule, flight time, number of landings and departures, and number of operations in the light of the technical documents prepared by the manufacturers. calendar based means maintenance done according to the calendar we know. For example, 12 months lh & rh engine inspections is a calendar based maintenance and if you do it on April 1, you have to do this maintenance on April 1 the following year. If the time is based, maintenance is followed, this time according to the actual flight time. For example, when you say "every 25hr" or "400 hr" maintenance, it is understood that you should perform that maintenance every 25/400 hours. There are both time and hourly maintenance, for example, they say "100hr / 12 months inspection" then whichever comes first then that maintenance is done. For example, it was over a year ago, but only 50 hours a year, then this maintenance is done because you caught the year, but after 3 months the plane flies 100 hours then you have to do the maintenance again.

landing-take-off and operation-related maintenance operate with a similar logic. For example, to run the aircraft engines on the ground, the apu-axuilary power unit, a tiny jet engine on the plane, is operated. This engine has a maintenance interval depending on the number of runs and is maintained when the limits in that range are full.
3 steps are the nightmare of a maintenance planner, to make maintenance as much as possible, not to do maintenance and maintenance. For example, when there is no reason to take care of it long ago, I throw it to 100 hours of maintenance, 25 hours before maintenance, it is described as insolence and incapacity. but let's say the plane will go to siberia and will not return for 3 months. then, as much care as possible, the calendar is tried to be reset, which is an extreme case.
If we count the contents of the technical documents used in maintenance
maintenance manuals; is the name of the main care books in the civil field. The name of the military versions is technical order. In these books, the systems of the aircraft are expressed with a number system starting from 00 to 100 (the air transport association of america -ata that established this system). military numbering is different but logic is the same. aircraft manufacturers write the maintenance books of the aircraft / helicopters they produce in accordance with this system. For example, boing or airbus or bell helicopter ata always writes servicing operations in chapter 12. so if you wonder about the servicing work of an airplane / helicopter, simply go and mix chapter 12 directly. With the ata 100 system, a standard has been reached on the basis of the book of maintenance work. Here you can immediately think of "I'm on x plane I have this system, but not on y plane, then what will be written in that chapter that produces y plane?" may come up. the answer is very simple, if the aircraft you produce doesn't have a specific system, then you leave that chapter blank, and technicians will understand that it doesn't have that system.

maintenance manuals are the holy books of aircraft maintenance. all transactions are done according to what is written here. manufacturers often update these books. The need for updating is done until the aircraft is released and completely removed from the market, but you will appreciate that over the years, the frequency of updates to books will decrease as that aircraft leaves the market. The book, which receives 3-4 or more updates every year in the first time, remains stable for a few years due to the usage usage, the number of aircraft decreases, etc. and generally they do not receive innovations for procedures other than cosmetic arrangements.

A short working summary of the relevant system is made in these books, troubleshooting and troubleshooting processes are briefly described (troubleshooting part), material removal-installation works are written in detail according to the failures and the maintenance of the system, system limits are explained, schemes are given, circuits are drawn, assembly pictures blah blah. the technician should understand every point attached to his head by looking at the book while performing maintenance or troubleshooting, and therefore the systems enter the books in detail.

maintenance books logically interconnected
that is, chapter 32 is the landing gear section, and there is a wheel assy (wheel assy; the name of the aircraft / helicopter wheels). ). Let's say you are going to replace the brake pad on the wheel assy while you are doing maintenance, but you cannot find the part number of the brake pad you will order. then you have to go through a different book where the parts of the system are numbered one by one until the bolt of the system, the name of this book is illustrated parts breakdown-ipb or illustrated parts catalog-ipc. these two are the same, just the naming is slightly different.

illustrated parts breakdown / catalog contains the numbered (sample) of all parts that make up the plane / helicopter from the largest to the smallest.

Thanks to this book, which system has how many washers, how many gear wheels, how many o-rings are there. How to do the assembly, where and what to put all is clearly visible. Thus, what is this part from, where is this problem, why is this problem increased?

aircraft / helicopters do not produce a company
Of course, a single brand is printed on the plane / helicopter, but there are maybe 100 different companies produced in the aircraft. For example, most batteries / helicopters produce a company called marathon-norco. elt-emergency locator transmitters kannad company production of aircraft thought signal. If there are parts from similar sub-industry, their own maintenance / repairs are made in line with their own books written by the company that produces the material. The original aircraft manufacturer company does not interfere with these books, it just writes a note in the maintenance manual "to look at this book" and find that book accordingly. These parts produced by sub-industry companies are called components, and their maintenance books are called component maintenance manuals. Maintenance intervals of these components are calendar / hour based. There are also books of the same name that the aircraft manufacturer wrote for the things he himself produced and designated as a component. This also describes the extra maintenance procedures specific to that component.

Well, let's say that in a maintenance performed in America, a very serious material error was found on one of the aircraft and this is required to be corrected or a different maintenance process that is not in the books should be applied immediately. then it takes a lot of time for the manufacturer to immediately run and update and publish the book. to prevent this, service bulletin, technical bulletin, information letters etc. short care notes are published with statements. These are technical publications focusing on a very specific job consisting of only a few pages and only describing that work, and it is desired to be applied within a certain period of time. these are mandatory or optional. the compulsory ones are those that will directly affect flight safety, the optional ones are things that may or may not apply, but will provide you with extra peace of mind when applied. I'm throwing your plane, there is a square profile carpet and the corner of this carpet rises and rises under the cockpit door over the years and is torn by the door's abrasion. With the optional technical bulletin, you can check this and replace the carpet with a more slender one. Here are the optional things happen in this logic.
Apart from this, there are books explaining much larger maintenance / repairs.
Normally aircraft maintenance is divided into two as line and base.

The maintenance we call line includes daily, weekly or monthly minor checks and lubricants and its main purpose is to ensure that the aircraft / helicopter can fly in the short term.

base maintenance is a phase in which the aircraft is pulled into the hangar, where it is opened and exhausted, and where large maintenance operations are carried out, and this requires some more detailed documents.

There are also major repairs, modifications on the aircraft that are only authorized by the manufacturer or the very large maintenance organizations that are authorized at the same level as the manufacturer, for which more advanced books are not used. these books are not given to everyone because the ability to implement that process requires a lot of experience, materials, equipment, and above all, authority.
the issue of care powers is a complex issue
Faa and EAa are the two main authorities that determine the principles of care powers in the world. Each country approves and distributes their maintenance powers according to their regulations, whichever is the region. For example, in Turkey, EAA regulations are valid and we are the only authority on civil aviation general directorate-SHGM maintenance powers. When you set up a company and say "I'll take care of x aircraft", there is a shgm that controls you in terms of equipment, materials, personnel, education, financial status and placement, and you can either get authorization or get it until your deficiencies are eliminated. You are also periodically audited by shgm within your current powers.

That's the book part. So how is the aircraft maintained?
The job is definitely not similar to car-truck vs. land vehicle maintenance, so there are those who say it and insult. The main thing in aircraft maintenance is the "write what you do, do what you write" principle and it is strictly followed and followed. In other words, while you are performing a care, a written source will be open with you, it will not be disassembled according to the head. If it happens, the pain will come out later, for example, you did not properly care, that part will be licking, you cannot unscrew the screw, you cannot disassemble the product, the tool breaks down, you put a little oil, the system malfunctions, you put it too much, the system explodes ... you have to live. For this reason, you should not do anything other than what is written, and whatever you have done, you should write it in the book of the plane, in the opened maintenance package. care records are records that are tried to be kept tight in every way because one of the first things to look for in an accident-crime is the care records.

maintenance records are actually an archive of the technician's operations on that aircraft. each aircraft / helicopter has a registry file stack and the maintenance is recorded there. these records are kept and continue to live with the aircraft until the aircraft is in service. In this way, you have a chance to determine what was done to the plane 20 years ago and who did it. If the records are not kept healthy, first of all, the men who keep the records of the plane are burned in a problem because they cannot prove themselves.
maintenance is immediately considered in plane / helicopter accidents because blame maintenance is an automatic reaction taught to man
however, the accident-crushing rate due to direct maintenance error is not very high (that is, a technician has put it in a wrong place, it has gone off, it has gone into the engine, the plane has fallen. I mean it). - Crimea is the result of this. For example, the user makes mistakes, the caregiver does not see, the business grows and eventually the crimes occur. If there is a maintenance error in the work, this is one of the easiest reasons to identify, because a material proof of the error definitely lies in the wreckage. records are also an undeniable source of evidence.

A self-checking mechanism (see quality) has been set up in the places that perform maintenance operations. The quality units of the care companies can supervise everyone, reconstruct the care they see against the rules or the application / registration is missing. In an accident crime, all the operations performed by quality are questioned at least as much as maintenance works because quality units perform a very important task since it is the first inspection line. Another control mechanism of maintenance is the maintenance operations that will affect the flight with a double signature. There is a supervizor here and while someone else is doing the maintenance, he checks whether the maintenance is done correctly, if the records are correct, and then he signs the job together with the technician who does the job. Thus, the responsibility is shared and the work done is supervised.

consequently, aircraft maintenance is a very strict and frequently audited process.
According to the head, doing business has a lot of material and spiritual responsibilities. the system is established through a complementary book chain of standards, between the interconnected planner-practitioner-supervisor triangle, and no one can deny their job, because if that man ignores his work, the other man's head will also burn. Therefore, everyone is looking after each other, the things that are missing are seen in some way and corrected as soon as possible.

The name of the book used by pilots is flight manual. Although this book of pilots focuses predominantly on use, some simple references and guides made from care books are also included in these books.

I cut it short, or if I write everything, I should write until morning.

planes, helicopters are like people
they all have seasonal illnesses, they all have their own character, they all want to be taken care of themselves like a child. maintenance is done by taking these needs into consideration. Aircraft maintenance is a business that is generally difficult, demanding, but has a feeling of professional satisfaction until the end.
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