A saab-340B pilot notices the left propeller oil pressure gauge pegging at 200 psi; then dropping to...

Attributes
ACN	752036
Time
Date	200709
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	SF 340B
Operating Under FAR Part	Part 121
Flight Phase	ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	752036
Events
Anomaly	aircraft equipment problem : critical non adherence : far non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	other
Factors
Maintenance	contributing factor : schedule pressure contributing factor : briefing performance deficiency : fault isolation performance deficiency : testing performance deficiency : repair performance deficiency : non compliance with legal requirements performance deficiency : inspection
Supplementary
Problem Areas	Maintenance Human Performance Aircraft Company
Primary Problem	Maintenance Human Performance

Narrative:

Upon taxi out; we noticed the left propeller oil pressure gauge moving erratically. Eventually the indication pegged at 200 psi and then down to about 30 psi and eventually settled back into the normal green arc. We returned to the gate and made a logbook entry and provided maintenance control with a maintenance log write-up. We were prepared for something like this since the same discrepancy had been written up 8 times since august. No defects noticed on the way to ZZZ however. Having the knowledge that this discrepancy was written up and signed off 8 times in less than a month it seems a little ridiculous. Perhaps there is an underlying problem at the company or perhaps it is as simple as a thorn in our side with this particular airplane. Either way; there is definitely an issue with this particular aircraft and the problem needs to be addressed and not masked with a band-aid. Provided maintenance log write-up to maintenance control and grounded the aircraft in an out station. Perhaps it is pressure for our maintenance personnel to quickly fix things to keep on-time performance numbers in the green. Perhaps it is just an anomaly in the system or bad parts. I don't really know; all I know is that it was written up 8 times prior to this occurrence. Does it really take 8 write-ups to get something fixed properly. Callback conversation with reporter revealed the following information: reporter states most of the previous eight log squawks occurred during flight. He refused the aircraft for further revenue flight; but ended up ferrying the same aircraft to their maintenance facility. The propeller oil pressure gauge continued to show erratic pressure readings on the ferry flight. There were no other propeller or engine performance problems and he believed the gauge or sensor was at fault. Reporter does not know the final fix for the erratic propeller oil pressure gauge.

Original NASA ASRS Text

Title: A SAAB-340B PILOT NOTICES THE LEFT PROP OIL PRESSURE GAUGE PEGGING AT 200 PSI; THEN DROPPING TO 30 PSI. EIGHT PREVIOUS LOG REPORTS FOR SAME ITEM WERE SIGNED OFF. ACFT FERRIED TO MAINT FACILITY.

Narrative: UPON TAXI OUT; WE NOTICED THE L PROP OIL PRESSURE GAUGE MOVING ERRATICALLY. EVENTUALLY THE INDICATION PEGGED AT 200 PSI AND THEN DOWN TO ABOUT 30 PSI AND EVENTUALLY SETTLED BACK INTO THE NORMAL GREEN ARC. WE RETURNED TO THE GATE AND MADE A LOGBOOK ENTRY AND PROVIDED MAINT CTL WITH A MAINT LOG WRITE-UP. WE WERE PREPARED FOR SOMETHING LIKE THIS SINCE THE SAME DISCREPANCY HAD BEEN WRITTEN UP 8 TIMES SINCE AUGUST. NO DEFECTS NOTICED ON THE WAY TO ZZZ HOWEVER. HAVING THE KNOWLEDGE THAT THIS DISCREPANCY WAS WRITTEN UP AND SIGNED OFF 8 TIMES IN LESS THAN A MONTH IT SEEMS A LITTLE RIDICULOUS. PERHAPS THERE IS AN UNDERLYING PROB AT THE COMPANY OR PERHAPS IT IS AS SIMPLE AS A THORN IN OUR SIDE WITH THIS PARTICULAR AIRPLANE. EITHER WAY; THERE IS DEFINITELY AN ISSUE WITH THIS PARTICULAR ACFT AND THE PROB NEEDS TO BE ADDRESSED AND NOT MASKED WITH A BAND-AID. PROVIDED MAINT LOG WRITE-UP TO MAINT CTL AND GNDED THE ACFT IN AN OUT STATION. PERHAPS IT IS PRESSURE FOR OUR MAINT PERSONNEL TO QUICKLY FIX THINGS TO KEEP ON-TIME PERFORMANCE NUMBERS IN THE GREEN. PERHAPS IT IS JUST AN ANOMALY IN THE SYS OR BAD PARTS. I DON'T REALLY KNOW; ALL I KNOW IS THAT IT WAS WRITTEN UP 8 TIMES PRIOR TO THIS OCCURRENCE. DOES IT REALLY TAKE 8 WRITE-UPS TO GET SOMETHING FIXED PROPERLY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATES MOST OF THE PREVIOUS EIGHT LOG SQUAWKS OCCURRED DURING FLIGHT. HE REFUSED THE ACFT FOR FURTHER REVENUE FLIGHT; BUT ENDED UP FERRYING THE SAME ACFT TO THEIR MAINT FACILITY. THE PROP OIL PRESSURE GAUGE CONTINUED TO SHOW ERRATIC PRESSURE READINGS ON THE FERRY FLIGHT. THERE WERE NO OTHER PROP OR ENGINE PERFORMANCE PROBLEMS AND HE BELIEVED THE GAUGE OR SENSOR WAS AT FAULT. REPORTER DOES NOT KNOW THE FINAL FIX FOR THE ERRATIC PROP OIL PRESSURE GAUGE.

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.

A saab-340B pilot notices the left propeller oil pressure gauge pegging at 200 psi; then dropping to 30 psi. Eight previous log reports for same item were signed off. Aircraft ferried to maintenance facility.