Fileva, the 55-year-old co-owner of S7, died Sunday along with her father
and the pilot when her six-seater aircraft crashed near Frankfurt, said the
airline, the main rival to Russia's flagship carrier Aeroflot.
Russia's Interstate Aviation Committee said it would help the German Federal Bureau of Aircraft Accident Investigation to probe the tragedy.
“The group is getting ready to fly out to Germany very shortly,” a spokeswoman said.
The six-seater aircraft went down in a field while flying from France to Egelsbach south of Frankfurt, German police said.
Fileva, whose husband is S7 CEO Vladislav Filev, was listed in 2018 by Forbes magazine as the fourth richest woman in Russia with an estimated fortune of $600 million.
Police said the aircraft was completely burnt out and the victims would probably only be formally identified in the coming week.
S7 Group, which owns S7 Airlines, said the circumstances of the tragedy “were not yet known.”
The company praised its chief as a “bright, caring leader and great person.”
Tributes and condolences poured in both from colleagues and rivals in the wake of Fileva's death.
Russian space agency chief Dmitry Rogozin called Fileva a “great aviation and space enthusiast.”
“Her death is a personal tragedy for us all,” he said on Twitter.
“They are completely decent businesspeople and built all of their business with their own hands,” independent media outlet The Bell quoted a former chief of the presidential administration, Alexander Voloshin, as saying.
Fileva and her husband built the company from scratch, turning it into what some observers call Russia's most efficient airline.
Initially called Sibir (Siberia), it re-branded itself as S7 in 2005 after two major disasters involving its planes.
S7 Group, a rare case of a successful family business in Russia, has been seeking to branch out into space, establishing Russia's biggest private space company, S7 Space.
Last year the company bought Sea Launch, a floating satellite launcher.