On April 28, 2013 a Saudi Arabian Airlines Boeing 777-300, HZ-AK16, equipped with two General Electric GE90-115B engines had been pushed back from the gate and was in the process of starting the No. 2 engine when the engine unexpectedly accelerated to a high power setting. The aircraft moved forward and could not be stopped with the brakes before it hit a parked push back tractor severely damaging the lower No. 2 engine nose cowl. The Kingdom of Saudi Arabia General Authority of Civil Aviation (GACA) is investigating the incident. As the state of manufacture of the engines and some airplane components, the NTSB has designated a United States Accredited Representative under the provisions of Annex 13 to the Convention of Civil Aviation to assist the GACA in the investigation. All inquiries concerning this incident should be directed to the GACA at: General Authority of Civil Aviation (GACA) Safety Department GACA – Safety & Economic Regulations P.O. Box 887 Jeddah 21241 Saudi Arabia Tel.: (966) 2 685-5515 / 5494 (966) 5 04626707 / 48695853 (mobile) E-mail:sd@gaca.gov.sa Fax: (966) 2 685-5507 Website:www.gaca.gov.sa