Central Mountain Airways Flight 785 Minimum Vectoring Altitude Incursions

Departure and Initial Vectors Central Mountain Airways Flight 785, a Beech 1900D, departed Vancouver International Airport at 1723 Pacific standard time on the POCO ONE standard instrument departure. The aircraft was following Canadian Regional Flight 1114, a slower-climbing de Havilland DHC-8, with both en route to Kamloops, British Columbia. The departure controller cleared the Beech 1900D to 7,000 feet and to turn to a heading of 010 degrees passing through 3,000 feet to vector around the slower traffic. The aircraft was later cleared to maintain 16,000 feet. ## First MVA Incursion While climbing through 6,100 feet, the Beech 1900D entered airspace where the minimum vectoring altitude was 7,000 feet. It reached 7,000 feet approximately 2.5 nautical miles inside the boundary. The first departure controller, who had four years of experience in the Vancouver Terminal specialty, had been on duty for 5.5 hours and had recently taken over both north and south departure positions. He was aware of the Beech 1900D's high climb performance and anticipated it would reach 7,000 feet before the boundary. He temporarily diverted his attention to resolve a separation requirement in the south departure area. ## Controller Response and Relief When the controller detected the incursion, he issued a heading of 080 degrees and requested an increased climb rate. He then altered the altitude clearance to 8,000 feet with a request for a good rate through 7,000 feet for terrain, and cleared the DHC-8 to 16,000 feet. The controller advised the terminal data controller of the occurrence and that he would need to be relieved, continuing to provide control instructions until the second controller was prepared to take over. ## Second MVA Incursion The second departure controller, with seven years of experience, took over quickly. He reported the transfer briefing was hurried and that he was under the impression the Beech 1900D had been cleared to 9,000 feet. After the aircraft had been cleared to maintain 8,000 feet, it continued climbing to 8,400 feet before returning to 8,000 feet. The second controller advised the pilot to keep climbing and turn back to a northerly heading, with further climb to be authorized in a couple of miles. The pilot misheard the transmission, and when repeated, the message included only the heading change and the advisory of a further climb. ## Detection and System Context The incursion into the 9,000-foot MVA sector at 8,400 feet was detected the next day during review of radar tapes. The Beech 1900D reached 9,000 feet approximately 20 seconds or about 1.5 nautical miles after penetrating the 9,000-foot MVA area. The pilot reported visual contact with both the DHC-8 and the terrain at all times. The minimum safe altitude warning system, designed to alert controllers to potentially hazardous altitude breaches, was not yet in operational use in Canada at the time.