Narrative:

I was the relief officer on aircraft X. Due to multiple aircraft malfunctions of the right pressurization/pneumatic system occurring on the ground and while airborne that impacted the margin of safety needed we needed [to return to departure]. The aircraft had a rt hpov EICAS message during our initial takeoff which resulted in a slow speed rejected takeoff. The aircraft was brought back to the gate and maintenance worked on it so that we were able to reattempt our departure. During climb out on our second departure we received a pack off light in the right system. Upon level off the crew ran the appropriate checklist for right pack off. Due to the complexity of our flight planning (high terrain and an ETOPS segment enroute due to lack of facility availability) the crew coordinated with maintenance; dispatch and the company. Maintenance evaluated the issue and the crew ran some expanded procedures to attempt to reset the right pack/isolate the malfunction. It would not reset therefore not be reliable for the remainder of the flight. Additionally; the crew coordinated with dispatch/company about options and safety concerns given the nature of our routing with multiple malfunctions in the right system. It was decided that the potential threats could not be mitigated enough for the flight to continue at an acceptable safety margin; so the decision was made to air return. The crew dumped fuel and landed heavyweight back uneventfully.

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Original NASA ASRS Text

Title: B767 flight crew reported encountering several engine bleed and air conditioning/pressurization malfunctions which resulted in an aborted takeoff and a subsequent air return to the departure airport. Additionally; a malfunction in the fuel jettison system resulted in an overweight landing.

Narrative: I was the Relief Officer on Aircraft X. Due to multiple aircraft malfunctions of the right pressurization/pneumatic system occurring on the ground and while airborne that impacted the margin of safety needed we needed [to return to departure]. The Aircraft had a RT HPOV EICAS message during our initial Takeoff which resulted in a slow speed rejected Takeoff. The aircraft was brought back to the gate and maintenance worked on it so that we were able to reattempt our departure. During climb out on our second departure we received a Pack Off light in the right system. Upon level off the crew ran the appropriate checklist for right pack off. Due to the complexity of our flight planning (High Terrain and an ETOPS segment enroute due to lack of facility availability) the crew coordinated with Maintenance; Dispatch and the Company. Maintenance evaluated the issue and the crew ran some expanded procedures to attempt to reset the right pack/isolate the malfunction. It would not reset therefore not be reliable for the remainder of the flight. Additionally; the crew coordinated with Dispatch/Company about options and safety concerns given the nature of our routing with multiple malfunctions in the right system. It was decided that the potential threats could not be mitigated enough for the flight to continue at an acceptable safety margin; so the decision was made to air return. The crew dumped fuel and landed heavyweight back uneventfully.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.