15 April 1992
Governments across the world applied United Nations (UN) sanctions against Libya because of its alleged involvement in the destruction of a Pan Am airliner over Lockerbie on 21 December 1988 and the bombing of a French plane over Niger in 1989. However, Organisation of African Unity (OAU) countries decided to ignore some of the sanctions imposed by the UN, including the flight ban. This was demonstrated when president of Niger, Ibrahim Bare Mainassarra, flew to Tripoli. President Mubarak of Egypt also flew to Libya to visit Colonel Gaddafi after seeking permission from the UN.
References

Solem, I., The Impact of the UN Sanctions Against Libya, from 11 septiembre 2001, [online], Available at www.11-septiembre-2001.biz [Accessed: 15 April 2014]|Medea, UN SC RESOLUTION 748 (SANCTIONS AGAINST LIBYA), from Medea, [online], Available at www.medea.be/en/ [Accessed: 15 April 2014]