Narrative:

About 1 minute after starting the left engine a vib caption appeared on the N2 gauge. I shut down the engine and returned to the gate where I wrote it up in the aml. Maintenance took the airplane for an engine run. Upon their return they advised me they had the same vib caption numerous times. The mdc confirmed it. Yet maintenance advised that with the concurrence of maintenance control they would balance the entry with 'aircraft ok for service.' maintenance control had faxed them a document allowing them to clear it that way. I read the documents. They did not look like part of any manual but rather e-mail between participants. I was not impressed and had more questions maintenance control could answer. The maintenance control controller reported that as the engines are getting older they are prone to vibrations outside the normal range. I reported our flight manual still requires us to abort a start for vibrations and I had no guidelines in the aom regarding flying the crj beyond limitations. At this point; I asked to be patched with the fleet manager. He confirmed what maintenance control had reported to me. When I asked for supporting documentation to be faxed or ACARS'ed to me; he advised me he did not have any. I told them I was not comfortable taking the airplane in revenue service. Wrote the discrepancy and ultimately refused the airplane. It is understandable as engines get cycles they will get out of tolerances. It is also understandable as a manufacturer gets more experience and data on a powerplant the engineers will be able to reassess the original limitations. But without these new limitations approved by the aircraft manufacturer and incorporated into the flight manual; pilots have no references to base their decision to fly an airplane with an engine vibrating beyond normal values.

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Original NASA ASRS Text

Title: ACR CAPT RPTS ENG VIB CAPTION ON ENG START ON CRJ-700. MAINT ADVISES IT IS OK TO DEPART; BUT HE REFUSES THE ACFT.

Narrative: ABOUT 1 MINUTE AFTER STARTING THE L ENG A VIB CAPTION APPEARED ON THE N2 GAUGE. I SHUT DOWN THE ENG AND RETURNED TO THE GATE WHERE I WROTE IT UP IN THE AML. MAINT TOOK THE AIRPLANE FOR AN ENG RUN. UPON THEIR RETURN THEY ADVISED ME THEY HAD THE SAME VIB CAPTION NUMEROUS TIMES. THE MDC CONFIRMED IT. YET MAINT ADVISED THAT WITH THE CONCURRENCE OF MAINT CTL THEY WOULD BALANCE THE ENTRY WITH 'ACFT OK FOR SVC.' MAINT CTL HAD FAXED THEM A DOCUMENT ALLOWING THEM TO CLEAR IT THAT WAY. I READ THE DOCUMENTS. THEY DID NOT LOOK LIKE PART OF ANY MANUAL BUT RATHER E-MAIL BETWEEN PARTICIPANTS. I WAS NOT IMPRESSED AND HAD MORE QUESTIONS MAINT CTL COULD ANSWER. THE MAINT CTL CTLR REPORTED THAT AS THE ENGS ARE GETTING OLDER THEY ARE PRONE TO VIBRATIONS OUTSIDE THE NORMAL RANGE. I REPORTED OUR FLT MANUAL STILL REQUIRES US TO ABORT A START FOR VIBRATIONS AND I HAD NO GUIDELINES IN THE AOM REGARDING FLYING THE CRJ BEYOND LIMITATIONS. AT THIS POINT; I ASKED TO BE PATCHED WITH THE FLEET MANAGER. HE CONFIRMED WHAT MAINT CTL HAD REPORTED TO ME. WHEN I ASKED FOR SUPPORTING DOCUMENTATION TO BE FAXED OR ACARS'ED TO ME; HE ADVISED ME HE DID NOT HAVE ANY. I TOLD THEM I WAS NOT COMFORTABLE TAKING THE AIRPLANE IN REVENUE SVC. WROTE THE DISCREPANCY AND ULTIMATELY REFUSED THE AIRPLANE. IT IS UNDERSTANDABLE AS ENGS GET CYCLES THEY WILL GET OUT OF TOLERANCES. IT IS ALSO UNDERSTANDABLE AS A MANUFACTURER GETS MORE EXPERIENCE AND DATA ON A POWERPLANT THE ENGINEERS WILL BE ABLE TO REASSESS THE ORIGINAL LIMITATIONS. BUT WITHOUT THESE NEW LIMITATIONS APPROVED BY THE ACFT MANUFACTURER AND INCORPORATED INTO THE FLIGHT MANUAL; PLTS HAVE NO REFERENCES TO BASE THEIR DECISION TO FLY AN AIRPLANE WITH AN ENG VIBRATING BEYOND NORMAL VALUES.

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.