Borivoj Galović

OPTIMIZING MAINTENANCE RELIABILITY PROGRAM FOR SMALL FLEETS

Reliability program is considered to be a very valuable means of achieving better operational performance (through decreased maintenance related problems in operation) and increased flight safety. For this reason, reliability programs are mandated by the regulations for all commercial operators. Depending on the size of the operator, implementation of reliability program can be carried out in various organizational forms. Small fleets represent too small a statistical sample to collect enough information for obtaining statistically significant and accurate data. Therefore usability of reliability program in very small fleets is questionable. The aim of this work is to highlight some problems related to maintenance reliability program for small fleets.

CHALLENGES OF TRANSITION FROM JOINT AVIATION AUTHORITIES/FEDERAL AVIATION ADMINISTRATION TO EUROPEAN AVIATION SAFETY AGENCY

The work presents certain challenges that occur in the process of preparation and gradual transition to the unique European agency/service of air traffic safety, as well as the interaction of EASA with other similar services/agencies in the world. The new agency, in the new legal and functional environment that is being created, has to take over painlessly and without any break, the important functions and responsibilities of the JAA/FAA related air traffic safety and airworthiness at the European and world level.

Fatique and Corrosion Issues for Safety Improvements in Aviation Industry

Analyzing structure elements in a design estimated lifetime, structure integrity and capability to withstand all loadings is highly reduced by the end of designed estimated lifetime. Durability and reliability of vehicle structures is a function of fatigue and corrosion issues, which respectively affects crashworthiness requirements and safety. In aviation industry, from the point of a structure design, three structure design generations could be differentiated: a) the generation where major structure design is based on static strength and build-in redundancy i.e. some fail-safe elements ; b) the generation introducing fail-tolerant structure design philosophy ; and c) the generation additionally introducing full scale fatigue testing to determine wide-spread fatigue damage and corrosion prevention and control program. Implementation of aircraft structure design and maintenance philosophy i.e. in aviation recommended and standardized programs such as Supplement Structure Inspection Program, Corrosion Prevention and Control Program, Wide-Spread Fatigue damage evaluation and Repair Assessment Evaluation, may result with significant contribution to safety level in automotive industry.

Influence of Wake-Vortex Turbulence on the Flight Safety

With the growing air traffic intensity, at some ai1ports weare more often faced with the fact that aircraft land or take offone after another. Since evety aircraft leaves a turbulent vortexbehind, which acts unexpectedly and is destabilising for theaircraft flying into it, the flight safety in such repeated landingsand takeoffs becomes questionable. Determining the minimumsafety time interval between the repeated operations becomesimperative and a limiting factor for some airports withhigh air traffic intensity. Unlike militaty flying, where crew istrained to fly in a group, in civil air traffic the crew is nottrained for such flying and on top of it mostly operate on largeaircraft, which produce very strong turbulent vortex. Additionalsophisticated equipment in new modem aircraft improvesnavigation, communication and steering of the aircraft, butdoes not insure it from flying into an invisible turbulent vortex.This paper discusses the vortex generation, its nature and fa ctorsthat influence its intensity and duration. The paper alsodeals with a model of calculating the probability of flying intoa turbulent vortex regarding time intetval of repeated opera tions,and influence of sophisticated equipment installed, onthe stability and flight safety of an aircraft. Conclusion underlinesthe need to standardise the minimum safety time intervalseparation between the repeated operations, with the aim ofimproving flight safety.

Considerations Regarding Development of Alternative Propulsion in Aviation

Ecological indications and the depletion of fossil fuel resourcesare the main reasons for current studies of alternativepropulsion in aviation i.e. for searching for new regenerativeenergy sources. The technical and technological presumptionsfor the transfer from the conventional to alternative fuel aremore radical than the transition from piston to jet propulsion.The main problems include the production of liquefied hydrogen,the necessary aircraft structure modifications, and the requiredinfrastntcture supporl.

Primjena vektoriranog potiska s osvrtom na superupravljivost istraživackog zrakoplova X-31A

Vectored propulsion is a new concept of aircraft attitudecontrol by engines jet-deflection. Thrust vectoring researchhas become actualized during the last ten years, mainly formilitary application.The carried out experimental projects confirm the effectivenessof the thrust-vectoring systems in both conventionalaircraft attitude control and post-stall maneuverability enhancement.Apart from military aviation, the results of thrust-vectoringresearch are applicable in civil aviation, especially in STOLand VTOL aircraft design.

Ekološki kriteriji eksploatacije zrakoplova

Respecting the requirements for preservation and protectionof the environment, the present day is marked by implementation of legislative regulations in order to reduce the adverseeffects of transport vehicles.The increasingly strict eco-regulations in air traffic areaimed at reducing the aircraft engine emissions and gradualelimination of noise producing aircraft.Apart from the USA, operational restrictions have been announcedalso by other ICAO members, such as the ECACcountries, Australia, Japan and New Zealand.In spite of a good geo-traffic position and the tendency ofintegration into the European and world traffic routes, Croatiahas found itself, due to the process of gaining independence,defending its vital national interests and organization of civilaircraft authorities, lagging behind with the implementation ofthe present international regulations regarding environmentalprotection criteria in aircraft operations.