Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 125; Flight Crew Total 10000; Flight Crew Type 749
Aircraft Equipment Problem Critical
Flight Crew Diverted; Flight Crew Landed in Emergency Condition; Flight Crew Requested ATC Assistance / Clarification
Aircraft
As we were climbing to 34;000 we received the Right Pack off indication and the associated [alert] messages. We were right in the tops of the clouds and requested a climb to 36;000 to try and get in the clear sky. We had been flying with the Left pack in the off position; due to the cockpit noise levels. As soon as the right pack off indications happened we immediately selected the left pack back to auto. Shortly after this; but before reaching 36;000; the left pack off indications posted. Bleed pressure for both systems now read zero. At this time we began an immediate descent to 10;000 feet and continued the pack off checklist. We determined that the nearest suitable airport to us was ZZZ. There were thunderstorms in the area; which required some deviating; but the temperatures were high enough that anti-ice was not required. We set up for and briefed the ILS at ZZZ and landed without incident. We informed Center; Approach and Tower that no further assistance was required.
Climbing through 34;000 ft MSL; received Right Pack Off EICAS and Right Pack off Light. At 36;000 ft received Left Pack Off EICAS and Left Pack Off Light.
B757 flight crew reported the flight diverted due to loss of both Air Conditioning and Pressurization Packs and landed without further incident.