Narrative:

I was the flight maintenance representative on aircraft X. After arrival at the station; I noted that a fan blade on #4 engine had a distortion (bend) at the tip (area 'D' of boeing airframe maintenance manual). I measured the distortion. I recall measuring and recording the total distortion displacement as approximately 0.400 inches with a length of distortion as approximately 2.5 inches (I don't recall the exact dimensions at this time). The distortion dimensions I measured were within the limits described in amm 72-31-02 page 601 1C (2)(T); which allows up to 0.500 inches of distortion with a maximum distortion length of 6 times the distortion displacement (so; maximum 0.5 inches by 3.0 inches). The damage I recorded was within these limits. I made an aircraft maintenance log entry detailing the damage and my findings that the damage was within serviceable limits. Since that time; several other company representatives have examined the damage; made measurements; and forwarded photographs to headquarters with statements corroborating my findings in the field. However; since then; apparently; the dimensions of the damage have changed -- whether by the hand of another attempting to work-out the distortion (undocumented) or by subsequent additional damage; I cannot say. The damage was as I described and documented at the time I described and documented it.

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Original NASA ASRS Text

Title: A B747-200 ACFT #4 ENGINE FAN BLADE WAS FOUND WITH A BEND AT THE BLADE TIP. MEASUREMENTS WITHIN LIMITS AND CORROBORATED. LATER MEASUREMENTS FOUND BLADE BEND OUT OF LIMITS.

Narrative: I WAS THE FLT MAINT REPRESENTATIVE ON ACFT X. AFTER ARR AT THE STATION; I NOTED THAT A FAN BLADE ON #4 ENG HAD A DISTORTION (BEND) AT THE TIP (AREA 'D' OF BOEING AIRFRAME MAINT MANUAL). I MEASURED THE DISTORTION. I RECALL MEASURING AND RECORDING THE TOTAL DISTORTION DISPLACEMENT AS APPROX 0.400 INCHES WITH A LENGTH OF DISTORTION AS APPROX 2.5 INCHES (I DON'T RECALL THE EXACT DIMENSIONS AT THIS TIME). THE DISTORTION DIMENSIONS I MEASURED WERE WITHIN THE LIMITS DESCRIBED IN AMM 72-31-02 PAGE 601 1C (2)(T); WHICH ALLOWS UP TO 0.500 INCHES OF DISTORTION WITH A MAX DISTORTION LENGTH OF 6 TIMES THE DISTORTION DISPLACEMENT (SO; MAX 0.5 INCHES BY 3.0 INCHES). THE DAMAGE I RECORDED WAS WITHIN THESE LIMITS. I MADE AN ACFT MAINT LOG ENTRY DETAILING THE DAMAGE AND MY FINDINGS THAT THE DAMAGE WAS WITHIN SERVICEABLE LIMITS. SINCE THAT TIME; SEVERAL OTHER COMPANY REPRESENTATIVES HAVE EXAMINED THE DAMAGE; MADE MEASUREMENTS; AND FORWARDED PHOTOGRAPHS TO HEADQUARTERS WITH STATEMENTS CORROBORATING MY FINDINGS IN THE FIELD. HOWEVER; SINCE THEN; APPARENTLY; THE DIMENSIONS OF THE DAMAGE HAVE CHANGED -- WHETHER BY THE HAND OF ANOTHER ATTEMPTING TO WORK-OUT THE DISTORTION (UNDOCUMENTED) OR BY SUBSEQUENT ADDITIONAL DAMAGE; I CANNOT SAY. THE DAMAGE WAS AS I DESCRIBED AND DOCUMENTED AT THE TIME I DESCRIBED AND DOCUMENTED IT.

Data retrieved from NASA's ASRS site as of January 2009 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.