- 33 - CDL-AD(2006)009 144. The situation may arise that a Council of Europe member State has serious reasons to believe that the mission of an airplane crossing its airspace is to carry prisoners with the intention of transferring them to countries where they would face ill-treatment. 145. If such an airplane does not require landing, as long as the plane is in the air, all persons on board are subject to the jurisdiction of both the flag State and the territorial State. In the Commission’s view, Council of Europe member States’ responsibility under the European Convention on Human Rights is engaged if they do not take the preventive measures which are within their powers. In addition, their responsibility for aiding another State to commit an unlawful act would be at issue. It follows, in the Commission’s view, that the territorial State is entitled to, and must take all possible measures in order to prevent the commission of human rights violations in its territory, including in its air space. 146. There are obviously practical difficulties involved in securing the effective enjoyment of Convention rights in aircraft transiting a Council of Europe member State’s airspace or military base for foreign forces on its territory. Without prejudice to the wider question of how such difficulties can affect the scope of a State’s obligations to secure generally the rights under the Convention, the case-law of the European Court of Human Rights makes it clear that the State’s duty to secure the most elementary rights at issue in the present case (right to security of person; freedom from torture and right to life) continues to apply, regardless of acquiescence or connivance89. 147. The territorial State possesses a different course of action in respect of the suspect airplane, depending on its status. 148. If the state airplane in question has presented itself as if it were a civil plane, that is to say it has not duly sought prior authorisation pursuant to Article 3 c) of the Chicago Convention, it is in breach of the Chicago Convention : the territorial State may therefore require landing. The airplane having failed to declare its State functions, it will not be entitled to claim State aircraft status and subsequently not be entitled to immunity : the territorial State will therefore be entitled to search the plane pursuant to Article 16 of the Chicago Convention and take all necessary measures to secure human rights. In addition, it will be entitled to protest through appropriate diplomatic channels. 149. If the plane has presented itself as a State plane and has obtained overflight permission without however disclosing its mission, the territorial State can contend that the flag State has violated its international obligations. The flag State could thus face international responsibility. The airplane however will, in principle, be entitled to immunity according to general international law and to the applicable treaties: the territorial State will therefore be unable to search the plane, unless the captain consents. 150. However, the territorial State may refuse further overflight clearances in favour of the flag State or impose, as a condition therefore, a duty to submit to searches. If the overflight permission derives from a bilateral treaty or a SOFA or a military base agreement, the terms of such treaty might be questioned if and to the extent that they do not allow for any control in 89 See European Court of Human Rights, Ilascu and others v. Moldova and the Russian Federation, judgment of 8 July 2004, § 318, Riera Blume and others v. Spain judgment of 14 October 1999 (final 14/01/2000) §§ 34-35; Gongadze v. Ukraine, judgment of 8 November 205, § 165.