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
On initial climbout; observed EICAS messages 'L PACK OFF' & 'L ENG BLEED OFF' with corresponding OFF lights in respective switches. Turned switches OFF per QRH. Shortly thereafter the R PACK & R BLEED began cycling on & off; with the R CTR FUEL TANK PUMP cycling on & off. Notified ATC of our intention to return and declared Emergency due to intention of making an overweight landing. Notified flight attendants; pax; station & dispatch. Landing accomplished normally with 200 fpm descent at touchdown at 216.0 GW. Utilized long rollout; no auto-brakes; minimal braking below 60 kts. Terminated emergency with ATC upon clearing runway for normal taxi to gate. No further issues.
No suggestions other than replace parts on a time schedule vs a fly to fail policy.
On initial climbout; B757 flight crew observed EICAS messages for L PACK OFF & L ENG BLEED OFF. The switches are turned off per the QRH and shortly after the R PACK & R BLEED began cycling on & off and also the R CTR FUEL TANK PUMP. The crew elects to return to the departure airport.