B757-200
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport; General Declared Emergency
Aircraft; Weather
On climbout the Captain tried to engage the engine anti-ice. The Left Engine Valve light in the button remained on and the accompanying L-ENG Anti-Ice EICAS Message was displayed. After checking the enroute and destination weather conditions; we determined the engine anti-ice was required for the flight. We decided to return and declared an emergency for the overweight landing. I checked the climb limited landing weight and the runway limited landing weights as per the overweight landing procedure in the QRH. We determined the landing performance weights were not a factor. The Captain elected to make a flaps 25 landing. The touchdown was very smooth. VVI at TD was 100-200 FPM down. Reverse thrust only was used to stop the aircraft. A visual inspection of the brakes was made by ARFF after clearing the runway. Brakes were determined to be 'cold to the touch' by ARFF. The emergency was terminated and we taxied to the gate normally.
B757 First Officer reports engine anti-ice valve failure to open during climb. With a long flight ahead and icing conditions in the forecast; the crew elects to return to the departure airport for an overweight landing.