With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Martina Navratilova is a baseball player.
text_B: Aviation communication refers to the conversing of two or more aircraft .. aircraft. aircraft. Aircraft are constructed in such a way that make it very difficult to see beyond what is directly in front of them .. As safety is a primary focus in aviation , communication methods such as wireless radio are an effective way for aircraft to communicate with the necessary personnel .. aircraft. aircraft. Aviation is an international industry and as a result involves multiple languages .. However , as deemed by the International Civil Aviation Organization -LRB- ICAO -RRB- , English is the official language of aviation .. The industry considers that some pilots may not be fluent English speakers and as a result pilots are obligated to participate in an English proficiency test .
not_related.