Old Fella: Good show sorting out that EGT indication problem.
As a stateside product support engineer, I was once confronted with a customer's engine with several percent high fuel flow. After a telex or two over a 10000 km distance, we deduced the actual fuel burn did not match the excess shown on the FF gage.
Then I found there were two different FF transmitters, with different calibration points (low vs high FF). They looked identical, same basic p/n, different dash number. Swapped the transmitter for the correct item, customer satisfied.
While this problem was quite benign, the
Tuninter ATR72 crew had a related problem that was not so minor.