Shortly before the plane dropped off the radar, the pilot requested to fly at a lower altitude, Iran’s Civil Aviation Authority told local news media outlets. Images on social media showed a large plume of black smoke emerging from the Zagros Mountains near Shahr-e Kord in Chaharmahal-Bakhtiari Province.

Melike Kuvvet, the captain of the jet, was one of the first female pilots in the Turkish military, before she resigned and started to work in the private sector, Turkish news media reports said.

The bodies of the passengers and crew could not yet be identified, a spokesman for Iran’s emergency services, Shahin Fathi, was quoted as saying by Iranian news agencies. DNA tests will be conducted to identify the dead.

After the crash was reported, Mr. Basaran went to Iran, the Turkish news media reported.

Ms. Basaran was posting images of her trip to her popular Instagram account, which has more than 58,000 followers. The final photo posted shows her with seven female friends, smiling in pink and white robes. Another image showed her aboard the plane with a large bouquet of flowers.