Junkers G 31 above the Rila Monastery (Bulgaria 1932)

Stamp Junkers G 31 above the Rila Monastery it reflects the thematic directions:

Religion is any cultural system of designated behaviors and practices, world views, texts, sanctified places, ethics, or organizations, that relate humanity to the supernatural or transcendental. Religions relate humanity to what anthropologist Clifford Geertz has referred to as a cosmic "order of existence". Different religions may or may not contain various elements ranging from the "divine", "sacred things", "faith", a "supernatural being or supernatural beings" or "some sort of ultimacy and transcendence that will provide norms and power for the rest of life". Religious practices may include rituals, sermons, commemoration or veneration (of deities), sacrifices, festivals, feasts, trances, initiations, funerary services, matrimonial services, meditation, prayer, music, art, dance, public service, or other aspects of human culture. Religions have sacred histories and narratives, which may be preserved in sacred scriptures, and symbols and holy places, that aim mostly to give a meaning to life. Religions may contain symbolic stories, which are sometimes said by followers to be true, that have the side purpose of explaining the origin of life, the Universe and other things. Traditionally, faith, in addition to reason, has been considered a source of religious beliefs. There are an estimated 10,000 distinct religions worldwide. About 84% of the world's population is affiliated with one of the five largest religions, namely Christianity, Islam, Hinduism, Buddhism or forms of folk religion.

Aviation is the practical aspect or art of aeronautics, being the design, development, production, operation and use of aircraft, especially heavier than air aircraft. The word aviation was coined by French writer and former naval officer Gabriel La Landelle in 1863, from the verb avier (synonymous flying), itself derived from the Latin word avis ("bird") and the suffix -ation.

An aircraft is a machine that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines. The human activity that surrounds aircraft is called aviation. Crewed aircraft are flown by an onboard pilot, but unmanned aerial vehicles may be remotely controlled or self-controlled by onboard computers. Aircraft may be classified by different criteria, such as lift type, aircraft propulsion, usage and others.