Narrative:

Aircraft was being repositioned to base following completion of unscheduled maintenance. It was noted during aircraft operation that engine #2 oil pressure was higher than engine #1; but remained in the green range. During flight the oil pressure on engine #2 did go into the yellow caution range momentarily (approximately 117 psi) several times for very brief periods of time (seconds). No other abnormal engine readings were noted. The QRH was consulted and the flight continued to base in accordance with appropriate checklists and limitations. A logbook entry was made upon arrival and maintenance control was notified.three days later it was noted; through a personal conversation with a mechanic; that a report had been submitted regarding this flight. After the fact the flight crew learned that once the aircraft in question arrived at the hanger it was noted that there was a crack in the engine casing near the oil sump/lubrication system that required an engine change. It was also noted (through hear-say) that it was known by maintenance control (through recorded telephone conversations) that there was a potential crack noted by the mechanics working on the aircraft in the departure airport and that the flight was signed off and allowed to proceed despite company procedures being in effect to the contrary. It is the belief of the flight crew that we received an airworthy aircraft (as determined by appropriate maintenance log sign offs and communications); that we followed all appropriate procedures in operation of that aircraft; and that we were able to safely pilot the aircraft to destination. Some abnormalities regarding the engine (#2) were noted during flight; and these discrepancies were both verbally communicated to maintenance control utilizing a radio call as well as written in the aircraft log. However; what we did not know is that there was a crack in the engine casing and that maintenance knew about this crack and decided to sign off the aircraft anyway most likely to get the aircraft back to avoid extensive outstation repairs (from what I gather through communication with several maintenance personnel; an engine change is conducted anytime a crack is found).if the information is true and the aircraft was allowed to depart in a non airworthy condition; I am very disappointed and concerned. As a flight crew; we trust maintenance to maintain aircraft in accordance with federal aviation regulations and to the highest degree of safety possible. There are a lot of things that flight crews cannot observe during a preflight inspection or just simply are not trained to know. The flight crew would have had no way to determine if there was a crack in the engine casing and so we placed trust in the three mechanics. When they did this with the proper sign off and personal affirmations that the aircraft was 'good to go;' we trusted that this was correct and brought the aircraft back.

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Original NASA ASRS Text

Title: CRJ200 flight crew was informed after the fact that they may have ferried an aircraft in an non airworthy condition. A crack in an engine casing or seal; that was apparently known to maintenance prior to flight; required an engine change after the flight.

Narrative: Aircraft was being repositioned to base following completion of unscheduled maintenance. It was noted during aircraft operation that engine #2 oil pressure was higher than engine #1; but remained in the green range. During flight the oil pressure on engine #2 did go into the yellow caution range momentarily (approximately 117 PSI) several times for very brief periods of time (seconds). No other abnormal engine readings were noted. The QRH was consulted and the flight continued to base in accordance with appropriate checklists and limitations. A logbook entry was made upon arrival and Maintenance Control was notified.Three days later it was noted; through a personal conversation with a Mechanic; that a report had been submitted regarding this flight. After the fact the flight crew learned that once the aircraft in question arrived at the hanger it was noted that there was a crack in the engine casing near the oil sump/lubrication system that required an engine change. It was also noted (through hear-say) that it was known by Maintenance Control (through recorded telephone conversations) that there was a potential crack noted by the mechanics working on the aircraft in the departure airport and that the flight was signed off and allowed to proceed despite Company procedures being in effect to the contrary. It is the belief of the flight crew that we received an airworthy aircraft (as determined by appropriate maintenance log sign offs and communications); that we followed all appropriate procedures in operation of that aircraft; and that we were able to safely pilot the aircraft to destination. Some abnormalities regarding the engine (#2) were noted during flight; and these discrepancies were both verbally communicated to Maintenance Control utilizing a radio call as well as written in the aircraft log. However; what we did not know is that there was a crack in the engine casing and that Maintenance knew about this crack and decided to sign off the aircraft anyway most likely to get the aircraft back to avoid extensive outstation repairs (from what I gather through communication with several maintenance personnel; an engine change is conducted anytime a crack is found).If the information is true and the aircraft was allowed to depart in a non airworthy condition; I am very disappointed and concerned. As a flight crew; we trust Maintenance to maintain aircraft in accordance with Federal Aviation Regulations and to the highest degree of safety possible. There are a lot of things that flight crews cannot observe during a preflight inspection or just simply are not trained to know. The flight crew would have had no way to determine if there was a crack in the engine casing and so we placed trust in the three mechanics. When they did this with the proper sign off and personal affirmations that the aircraft was 'good to go;' we trusted that this was correct and brought the aircraft back.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.