B757-200
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
General Declared Emergency
Aircraft
On approach left pack shut down; followed QRH procedure and continued; after calling for flaps 25; flaps locked out at 20 degrees. Pilot flying executed visual go around with flaps 20; declared emergency. Followed QRH procedure for trailing edge disagree and landed with flaps 20. No further problems and we proceeded to the gate.
B757 First Officer reported loss of left pack on approach; followed by flaps locking out at 20 degrees. Procedures were run for both anomalies; an emergency was declared; and a normal landing ensued.