ASRS Examples

Everyone in the aviation community has the ability to affectsafety. The examples below are taken from the ASRS and show thatthere are many players in the safety value chain. These examplesare provided throughout the book to illustrate issues in the actualwords of those commercial aviation professionals who experienced asafety event. The italicized portions that follow are the actual byaviation professionals to report the situation that they faced and1 they experienced. Following each narrative, there is a questionposed reader connect the report with the content of thechapter.

Maintenance

Title: Hydraulic System: crossed pressurelines

While troubleshooting the cause of two previous replacements ofhydraulic system reservoir pressurization manifold, a Maintenancefound that "crisscrossed" pneumatic pressure lines were preventingpressurization of the Blue hydraulic system.
After discovering that we were going to install [an A-319's]hydraulic pressure manifold for the third time, I decided to figureout why the folds were not pressurizing the Blue hydraulicreservoir to 50 PS I. hours of troubleshooting the problem, I foundthat the left engine . supply line in the left wheel well . . . wasconnected to a "tee" [fitting that sup plies all three hydraulicreservoirs thereby bypassing the [pre manifold completely andprobably over-pressurizing the reservoirs.

The Blue system pneumatic supply line (going to the hydraulicreservoir) was connected to a "union" [fitting], which is themanifold supply connection from the left engine thereby neversupplying pneumatic pressure to the Blue reservoir. So, the lineswere crisscrossed.
Both “B" nuts will fit on either connection and there is plenty ofroom for the lines to cross and not chafe on anything. It appearedthat neither line had been replaced . . . . When an Airbus comesinto the hangar, a low-pressure check of each Green, Yellow andBlue hydraulic reservoir’s head pressure is per formed using groundservice air. Although the Blue reservoir's head pressure was abovethe 22 PSI that sets off warnings in the cockpit, it was notpossible to increase the head pressure by applying service air tosee if the reservoir pressurization manifold was functioning.
When the Blue head pressure did not respond, the thought was thatthe mani¬fold was again at fault. The aircraft had been flying forsome time with the lines crossed, but since the Blue hydraulicreservoir head pressure never went below 22 PSI, no discrepancieswere noted. Maintenance history showed the aircraft did havehydraulic issues with the Green and Yellow systems oozing hydraulicfluid, but those discrepancies were probably caused by highreservoir head pressures from the crossed pneumatic supplylines.

Question for the reader: what are the ethical implications ofnot looking for the root issues behind recurring maintenanceproblems?