June 20, 1994
Incident at Gander Low Ocean (ATS operating irregularity)
FGEFZ (C425) BGBW 62/40 2313 FL200 63/30 BIRK GAF476 (ND16) CYYR 0ZN 2245 61/40 2314 FL210 63/30BIKF. FGEFZ issued clearance via Sonderstrom FIC at FL200. At 2257 on initial contact with Gander IFSS, reported passing FL200 for FL260. Before action could be taken to stop FGEFZ, flight had passed FL230 for FL260 and was recleared to maintain FL260 (2303). Aircraft occurrence filed. Operating irregularity occurred without ATC involvement.