UNPA
Article 42
Should the Security Council consider that measures provided for in Article 41 would be inadequate or have proved to be inadequate, it may take such action by air, sea, or land forces as may be necessary to maintain or restore international peace and security. Such action may include demonstrations, blockade, and other operations by air, sea, or land forces of Members of the United Nations.
Article 43
All Members of the United Nations, in order to contribute to the maintenance of international peace and security, undertake to make available to the Security Council, on its call and in accordance with a special agreement or agreements, armed forces, assistance, and facilities, including rights of passage, necessary for the purpose of maintaining international peace and security.
Such agreement or agreements shall govern the numbers and types of forces, their degree of readiness and general location, and the nature of the facilities and assistance to be provided.
The agreement or agreements shall be negotiated as soon as possible on the initiative of the Security Council. They shall be concluded between the Security Council and Members or between the Security Council and groups of Members and shall be subject to ratification by the signatory states in accordance with their respective constitutional processes.
UN Res. 1973: http://www.docstoc.com/docs/74644464/United-Nations-Resolution-1973-establishing-a-Libyan-No-Fly-Zone
Boehner letter: http://www.docstoc.com/docs/74548360/Libya-No-Fly-Zone-letter-from-Speaker-of-the-House-John-Boehner-to-President-Obama-about-administration-policy-in-Libya
