BAe 146-200A C-FBAO (msn E2111) of AirBC lost power in three of her four engines on 30 April, while en route from Winnipeg to Denver. She was at 29,000 feet, about 130 miles north of Denver when number one engine went to idle power. As she descended to 26,000 feet, power on numbers 2 and 4 engines also reduced to flight idle, and the captain declared an emergency. Power was restored after the aircraft descended to 10,000 feet. The captain cancelled the emergency and continued to Denver, where the flight landed without further incident. The 146’s ALF502R-5 engines are known to be vulnerable to power rollback due to icing, and an airworthiness directive (AD 96-14-09) imposes altitude and operating restrictions in icing conditions. A more recent AD (AD 99-15-06) requires installation of an improved fan core inlet anti-ice system, at the next shop visit, but no later than 31 December 2002.