Had a question on what - if any - slack Cathay has in its system.

I was on CX872 last night, which took a nearly two hour delay because of what staff thought was a mechanical problem with its right engine that held it up at its previous port of call, Manila. The flight came on board the displays an hour down, and once it arrived, maintenance crews there opened the right engine cowling and started shining lights. The delay then stretched to 100 minutes. The gate agents offered little information, saying that an engineer had to inspect the engine, but that they were not going to cancel the flight.

They soon did an engine run up at the gate and apparently seemed satisfied with the results as they called everyone to board. We got the op-up, thank goodness. We ended up down 2 1/2 hours, making up no time enroute due to unfavorable winds. I wasn't too bothered by that because I never schedule anything right at the end of a long haul trip anyway, and the op-up always helps , but I was curious as to the availability of spare planes.

The plane that operated this flight, B-KQM, is a 13-month old 77H according to FlyerGuide and Airfleets, one of 33. Is it plausible that Cathay is running all 33 77H in a single day? I noticed this bird had been running around South Asia all day, to Beijing and Manila, after running a TPAC from LA the previous night. Is this a typical cycle? Are Cathay less willing to cancel simply because they have no spare birds, or is it something else? They really seemed intent on having that plane do the SFO run that night...there was never talk of canceling or getting another bird to do the flight.