Prema odobrenom programu održavanja zrakoplova, zračni prijevoznik planira vrijeme izvođenja zadaća održavanja zrakoplova. Zadaće održavanja zrakoplova planiraju se za vrijeme boravka zrakoplova na zemlji kad zrakoplov nije planiran za letenje. Time se osigurava da potrebno vrijeme za izvršenje zadaća održavanja zrakoplova nema utjecaja na raspoloživost zrakoplova za letenje. Neplanirano održavanje nastaje zbog tehničkog kvara ili grešaka u procesu održavanja. Zbog neplaniranog zadržavanja zrakoplova na zemlji, dolazi do poremećaja u planiranom redu letenja, kašnjenja zrakoplova na let ili otkaza leta, a ujedno se zbog dodatnih radova povećavaju troškovi održavanja zrakoplova. Greške zbog utjecaja ljudskog faktora čine do 80% grešaka koje uzrokuju neplanirano održavanje zrakoplova, a nastaju zbog pridonosećih čimbenika koji dovode do njihovog nastanka. Stoga je primarno za svaku organizaciju otkriti pridonoseće čimbenike koji dovode do nastanka grešaka zbog utjecaja ljudskog faktora. Zračni prijevoznik može, izmjenama u sustavu održavanja i unutar svoje organizacije, otkloniti pridonoseće čimbenike za nastanak grešaka zbog ljudskog faktora. U radu je prikazan model proaktivnog upravljanja greškama u održavanju koji poboljšava pouzdanosti otpreme zrakoplova i omogućava učinkovito pronalaženje pridonosećih čimbenika za nastanak grešaka zbog utjecaja ljudskog faktora. Model koristi edukativne inspekcije za otkrivanje pridonosećih čimbenika koji dovode do nastanka grešaka zbog utjecaja ljudskog faktora i implementaciju motivirajućeg čimbenika za rad u izradi i implementaciji korektivnih mjera. Model je primjenljiv za sve vrste zračnih prijevoznika bez obzira na vrstu ili veličinu flote. Učinkovitost modela proaktivnog upravljanja greškama u održavanju kojim je poboljšana pouzdanost otpreme zrakoplova promatranog zračnog prijevoznika vrednovana je na početku istraživanja i tri godine nakon primjene modela. Studentovim t-testom s vjerojatnošću greške od 5% potvrđena je hipoteza prema kojoj je nakon tri godine primjene modela prosječna godišnja pouzdanost u otpremi zrakoplova kod prometranog zračnog prijevoznika za 2014. godinu bolja od prosječne pouzdanosti u otpremi zrakoplova za 2012. godinu. Istim testom potvrđena je hipoteza prema kojoj je prosječna pouzdanost otpreme zrakoplova promatranog zračnog prijevoznika za 2014. godinu bolja za oba tipa zrakoplova od prosječne svjetske pouzdanosti u otpremi zrakoplova za 2014. godinu.
|Abstract (english)|| |
According to the approved aircraft maintenance program, an airline plans aircraft ground time for scheduled maintenance tasks. Aircraft maintenance tasks are planned during ground time of aircraft when the plane is not scheduled to fly. This ensures that the time required to carry out aircraft maintenance tasks has no effect on the availability of the aircraft. Unplanned maintenance occurs due to technical failures or defects in the maintenance process. Unplanned aircraft maintenance on the ground has impact on the planned flight schedule, causing flight delays or flight cancellations, and additional work consequently increases aircraft maintenance costs. The human factor failures make up to 80% of the malfunctions that cause unplanned aircraft maintenance caused by the incentive factors that lead to their occurrence. Therefore, it is primary for each organization to find the incentive factors that lead to human factor error. An airliner may, through interventions in the maintenance system and within the organization, remove the incentive factors which lead to occurrence of human factors errors. The airline can eliminate the incentive factors for the occurrence of defects due to human factor. This paper presents a model of proactive management of malfunctions in maintenance that improve the aircraft dispatch reliability rate and can effectively find incentive factors for the occurrence of failures due to human factor. The model uses educational inspections to detect incentive factors that lead to human error and the implementation of motivating factor as part of corrective actions. The model is applicable to all types of airlines, regardless of the type or size of the fleet. The efficiency of the proactive model for the improvement of the aircraft dispatch reliability rate by managing maintenance errors was evaluated by comprising the aircraft dispatch reliability rate of the observed airline at the beginning of research and three years after the application of the proactive model. A Student T-test with 5% probability of error confirmed the hypothesis according to which after a three-year period of application of the model the average annual aircraft dispatch reliability of the observed air carrier for 2014 is better than the average aircraft dispatch reliability for 2012. The same test confirmed the hypothesis according to which the average aircraft dispatch reliability of the observed air carrier for 2014 is better for both types of aircraft than the average world aircraft dispatch reliability for 2014.The research was carried out in several phases which are summarized in the following chapters. In the first Chapter, “Introduction”, the problem of introducing errors into the aircraft maintenance system is described, explaining their impact on the aircraft dispatch reliability. It also presents an overview of the previous research in the area of the doctoral dissertation. Here, a hypothesis is set and the purpose and objective of the research are given. The second Chapter, “Aircraft Dispatch Reliability”, describes the standards for the design, construction and maintenance of parts, aircraft systems and aircraft that are required by the aviation authorities. The engineered reliability of the operation of parts and the system is described, as well as the influence of certain failures on aircraft safety and the probability of unscheduled failures that may occur during aircraft utilization based on the engineered reliability in operation. It also describes the conditions that need to be met by the air carrier in order to have the aircraft maintenance program approved. It describes the monitoring of the aircraft dispatch reliability that provides insight into the quality of the aircraft maintenance system of the air carrier and enables the air carrier to control the quality of their maintenance system. The third Chapter, “Impact of Human Factor on Aircraft Maintenance”, describes the most frequent causes of unscheduled aircraft maintenance, which consist of malfunctions that occur due to unintentional error in aircraft maintenance due to human factors. It presents the history of studying errors that occur due to human factor. It shows the tools for the analysis of failures that occur due to human factor, the current models that allow understanding, detection and elimination of the incentive factors that lead to their occurrence. The fourth Chapter, “Research of Errors due to Human Factor in the observed Aircraft Maintenance Organisation”, presents the errors due to human factor in the observed organisation. For the collected errors, the analysis and systematisation have been presented regarding certain incentive factors for the occurrence of error due to human factor according to the share of incentive factors for the occurrence of error and according to the impact on aircraft safety. The procedure of calculating the probability of repeating the error and the procedure of determining the impact of the error on aircraft safety have been described. An example of an error has been stated, which occurred in the observed organisation due to human factor in order to observe the procedure of analysis applied so as to detect the incentive factors for the error occurrence due to human factor. The division of errors has been presented according to the table of risks, and the calculation of the cost-effectiveness of investment into the elimination of maintenance errors. The fifth Chapter, “Improvement of Aircraft Dispatch Reliability through Proactive Management of Maintenance Errors”, presents the aircraft dispatch reliability in the observed organisation at the beginning of research. A comparison has been made of the aircraft dispatch reliability of the air carrier that has six aircraft of Airbus A320 type and six aircraft of Bombardier DHC-Q-400 type with the world fleet dispatch reliability of the same types of aircraft. Since the aircraft dispatch reliability was worse than the world fleet dispatch reliability, the model of standard management of errors in maintenance has been analysed. Based on the error analysis two novelties have been introduced into the model of standard management of errors in maintenance. Educational inspection has been introduced as additional part of the standard collection of data and a motivating factor has been set in the branch of developing corrective measures for preventing of error occurrence due to human factor. This has been the basis for developing a model of proactive management of errors in maintenance. The sixth Chapter, “Confirmation of Efficiency of Aircraft Dispatch Reliability Model through Proactive Management of Errors in Maintenance”, analyses the results of applying the model of proactive error management in maintenance in the traffic organisation for aircraft maintenance. The Student t-test with 5% probability of error was used to check the hypothesis, and the hypothesis has been confirmed, according to which: - the average annual in aircraft dispatch reliability in case of the observed air carrier was better for the year 2014 than the average reliability in aircraft dispatch for 2012 (for both types of aircraft); - the average aircraft dispatch reliability of the observed air carrier for the year 2014 is better than the average world dispatch reliability for 2014 (for both types of aircraft). The seventh, final Chapter, “Conclusion” synthesizes the results of the research of individual parts of the paper and shows the efficiency of applying the model of proactive error management in maintenance on the improvement of aircraft dispatch reliability with reference to possible further studies