Copied directly from the book Flags of the World [cra90i] by William Crampton (1990), the description is as follows:
'The arms are a secretary bird with a native shield on its breast; above it is a scroll with the motto, "Al Nadr Nila" (Victory is Ours), and beneath it is the name of the country.'
Paige Herring, 21 May 1998
Apparently Cramptom is wrong here, the text above eagle's head reads An-Nasr Lana, with the said meaning "Victory is Ours". The text below reads Jumhuriyat as-Sudan ad-Dimuqratiyah (=The Democratic Republic of Sudan).
Henry Churchyard, 6 April 2004