Article 48 Height keeping performance—aircraft registered in the United Kingdom

Unless otherwise authorised by the appropriate air traffic control unit, an aircraft registered in the United Kingdom shall not fly in reduced vertical separation minimum airspace notified for the purpose of this article, unless it is equipped with height keeping systems which enable the aircraft to maintain the prescribed height keeping performance capability.

The equipment required by paragraph (1) shall be approved by the CAA, installed and maintained in a manner approved by the CAA and shall, while the aircraft is flying in the said airspace, be operated in accordance with procedures approved by the CAA.

An approval granted by the CAA for the purposes of this article shall be in writing and may be subject to such conditions as the CAA thinks fit.