A view from one of the RAF test pilots - not the one who now works for RR, by the way
Chaps
I was one of the test pilots who did the trial on the new engine, and I don't now work for RR! I reply here because there seems to be some 'data' discussed based upon single-incident memories or recalled problems. Statistically this puts the 106 in a poor light and I agree with Sticktop Latearm in that the guys thought it was an improvement.
From my recall, the engine had a much greater thrust potential than the installed RAF fit, but I've forgotten the exact figures. On a practical level the reduced thrust allowed mixed fleet operation whilst it improved engine life.
The 106 was as robust as anything previously installed - which by the standards of many other engines in service is bomb proof (I've flown over 12 other modern fast jets that cause the pilots palpitations if the engine coughs). During the trial and subsequently when I operated the Jag with the 106, I was completely happy with the relight/light-up. The phrase in the thread that alludes to 'either lights up on the ground or in the air, but not both' sounds utter fantasy. This simply is not true.
Let's be careful that one instance of a remembered event does not detract from the truth that the Adours are very, very reliable work horse engines still operated with great confidence in many corners. The quote in SL's relpy sums it up for me:
'I don't know what the 106 serviceability stats were but I suspect that (excluding bird strikes) the Jag sooties spent far fewer nights away recovering sick jets than their Harrier or Tornado mates.'
WIL (first post on PPrune for years, but couldn't see this one drag on without comment)