NEW : Dead pilot used to engage in mock sword fights when in Turkish air force . Investigators : Turkish military plane dropped almost vertically to ground . Watch crash survivors return home » . Sudden drop because aircraft did not have enough forward speed , official says . Three Boeing employees killed , one remains hospitalized , company says .
NEW : Dead pilot used to engage in mock sword fights when in Turkish air force . Investigators : Turkish military plane dropped almost vertically to ground . Sudden drop because aircraft did not have enough forward speed , official says . Three Boeing employees killed , one remains hospitalized , company says .