Flightwatch
Apparently RR do not know the reason for this situation
RR are fully aware of the main driver for this situation, that is birdmouth wear and are working towards a solution. But, yes it's not a 5 minute fix.
is there anybody in BA/CX/QF who can state whether these companies are suffering the same problems? Is it only apparent in the H-T or does it happen to the G/H also?
Yes other operators are experiencing this, speak to your local smooth talking bar steward RR rep. CX did, and were told everyhting was pretty much fine with other operators.
There is some speculation the the relatively high cycles in CV at high weights together with the high utilisation of a/c (15+ hours/day) may play a part. If it is apparent in other companies are there any new crew procedures being promulgated to alleviate this?
Yes related to cycles, again RR aware that engines over 2,000 cycles are coming into the band of birdmouth wear. No, it is not related to crew operations as far as RR are aware, or so they say.
Deterioration of the -T is not uniform from engine to engine. CX has seen engines surge at a shade under 2,000cyc and others that can achieve 4,200 cyc before scheduled removal with not one surge.
Also it is a non Trent core and it constantly runs 30C hotter than the rest with a potential over temp over 24C MSL
Adding the Trent core to the knackered old 524H gave it an instant EGT margin boost of about 35 degC. RR haven't upgraded any of their tired 524's to the -T as far as we know.
gas path
I believe RR can monitor for this in the trend monitoring thats downloaded during flight.
Sadly RR cannot detect this deterioration underneath the normal ECM trends as it is too gradual. But, you are right about the deterioration mode.
Although, I'm sure you remember the good old 535C 'spike-check'. They have got something similar developed to light up the night sky on the 524-T.