Date: 201704
Aircraft: B757 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Initial Climb
Aircraft component: Engine Pressure Ratio Indicat
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Communication Breakdown
Anomaly: Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Other / Unknown
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Aircraft Automation Overrode Flight Crew; Flight Crew Overcame Equipment Problem
Contributing factors: MEL; Procedure; Aircraft
Primary problem: Aircraft

Narrative: The aircraft had multiple write-ups inbound that affected Engine indications; auto throttles; flight director; and autopilot. The First Officer (FO) side flight director was intermittently malfunctioning (Right FCC issue). Maintenance (MX) tested the system and signed off the discrepancy as it passed tests. As I was pilot flying; this issue would present itself again in flight causing the autopilot to kick off at altitude. We resolved the issue by switching to the center FCC on my side and using the center autopilot. The EPR xmitter CB had popped on the previous flight and would not reset. This caused the EPR indication on the left engine to be missing. After much discussion and MX going back and forth on the decision; they decided to apply a MEL which deffered the EPR gauge. This had various impacts including performance limitations; loss of Electronic Engine Controls (EECs); requirement for max thrust takeoff; and procedural changes for determining thrust setting. Immediately; upon reviewing the MEL; we knew there were going to be several threats associated with this deferral. We thoroughly reviewed and briefed all procedures and threats that we anticipated. We did feel there was a bit of ambiguity surrounding the proper procedures for setting the thrust throughout the flight. The MEL directed us to the performance section of the flight manual to determine appropriate alternate thrust settings for max climb; max cruise; and go around. However; the flight manual also described a procedure by which we would set EPR on the engine with the operative EPR gauge; and then set the N1 on the other engine to match. This created confusion as we were not certain as to which method was appropriate for determining correct thrust setting. It may be necessary to review and rewrite this section of the flight manual and MEL to provide more clarity.The aircraft on takeoff was quite a handful as I assumed it would be. We were roughly 50;000 pounds below max gross; conducting a max thrust take off on a cool day at sea level and our initial level off altitude was 2500 feet. Needless to say; the workload was very high as we were flying the departure; making sure we didn't blow through the altitude; and also making sure that the aircraft did not blow through the flap speeds as it really wanted to accelerate quickly; even with a relatively high pitch angle. In the process of the departure; there was some confusion with approach as to the heading he assigned when we checked in. We eventually cleared up the confusion. I'm not sure if we heard the heading wrong; or he mistakenly gave us the wrong heading.Lastly; the aircraft had various anomalies during climb out and cruise. Initially; the FMCs were not providing fuel; time; or path data during the climb out; thus VNAV would not engage. It was not until we reached our cruise altitude that this information was provided. We began to wonder if perhaps there were some collateral side effects of the popped EPR xmitter CB that were overlooked. As a precaution; we discussed the issue in flight with dispatch and maintenance and monitored everything closely throughout the flight. Ultimately; we were able to safely continue to our destination without incident. However; it might be wise to review the application of the MEL as it relates to the EPR xmitter CB.




Synopsis: B757 First Officer reported multiple issues that affected Engine indications and the Flight Control Computers.