As the terrain-following radar scans the ground ahead of the aircraft the actual clearance height is measured by the radio altimeter.

In some, probably in most, contact-areas a good deal of white mica is newly-formed.

John Prendergast, a former Clinton administration official and antigenocide activist who has worked in Chad and Sudan for 20 years, said Sudan had been trying to overthrow Mr. Déby because of his support for Darfur rebel groups and his willingness to allow a European peacekeeping force to deploy in Chad to protect Darfur refugees living on the country’s eastern border with Sudan.

Those with more sauvignon blanc can take on a brash grassiness, while those that are entirely verdejo or have more viura, the traditional grape of white Rioja, tend to be more mineral-y and floral with a richer texture.