The RR equipped 757 I was flying recently had no EPR indication on one engine. Now I'm fairly new to all this 'grown up' aeroplane stuff, but my initial thought was that we would probably have to use the other engine's EPR gauge as a guide for the u/s one. As it happens that was a totally wrong assumption. In such a situation there are a lot of weight penalties to apply in all phases of flight. No derating allowed and then reference to N1 parameters in the QRH. I don't have the MEL to hand to quote exact figures, but around 7,000Kgs penalty is applied. Use of the auto throttle is not allowed either and VNAV doesn't work. I'm still doing my home work to try and fully understand what was going on because the FD pitch commands, immediately after rotation, went full scale up.
Further more there is no over boost protection from the EEC (which normally look after N1 parameters) in this situation-apparently.
Should anybody have a full explanation about all aspects and implications, I would be most grateful to learn more.
Thanks in anticipation,
SFD