Rafael Ferro

Reviewing the subject NPRM we have concluded that this AD shall be applicable to TAM V2500 engine fleet. Therefore we would like to submit the following comments for review of this rule: #1 Should not the criteria for engine inspection be determined by EGT Margin deterioration rate, instead of having a fixed EGT Margin value (45°C)? We consider this criterion very subjective and not adequate for this purpose, once the EGT Margin value does not reflect by itselft only the engine deterioration condition. Our suggestion would be to merge the current criteria with high EGTM deterioration rate (°C/1000FH) and/or EGTM abrupt trend shifts. #2 Should not IAE/FAA consider different scenarios on the A5 thrust levels (24k, 27k, 27Ek, 33k), instead of having 45°C standardized for all of them? As you can observe on the attached EGT Margin plot, while this engine was installed on an A320-232 (27k)aircraft the EGT Margin was above 80°C (ISA + 15°C). After installation of this engine on an A321-231 (33k) aircraft, without any further service or repair in the meantime, it has dropped to less than 60°C (ISA + 15°C). Our suggestion is to include on this NPRM a management description of how should these engine position changes be managed after going back above the EGT margin threshold. #3 Regarding the terminating action we support the inclusion of EASA20.j DOA modified parts as an alternative method of compliance. Sinceraly, Rafael Ferro V2500 Powerplant Engineer