Take it the other engine was taking some of the load?
If one had failed, the remaining would be taking
all the load.
Think about it as a car having two engines going into one gearbox. Using a clever free wheel arrangement, both engines provide power to the gearbox in roughly equal amounts. Power from the gearbox then goes to the wheels (Rotor and tail rotor). If one engine failed, the other needs to provide double the power to keep the wheels turning at the same speed. (A constant rotor speed is what is required).
For example, a Lynx helicopter (twin engined) in the cruise would be showing approx 70% torque (power indication). Thats both needles (one for each engine) showing 70% each. If one engine failed, the failed engine torque needle would fall to zero and the remaining engine torque would effectively rise and read 140%. Because it has now had to double its power to maintain rotor speed (a governor senses a drop in rotor rpm and puts more fuel into the remaining engine to compensate). You are now thinking 'how can you have 140%??' Simple. Think of the '70%' twin engine torque as 35% in real terms. Ie; its working at 35% of its capacity. An engine fails, it then- in real time, is working 70% (so you still have about 30% to go on one engine before you run out of power on that engine). Thats the theory! With me?
It's just a way of making the indications more readable.
While I'm here, here's another that was buzzing over me:
You hadnt just nicked a Cavalier SRi had you??