(f)
Set the recharging unit pressure regulatorto deliver 50 psig and let the system purge for I hour. If any odor is still present. repeat the procedure for 1 or more hours. If the odor persists after the second purging,replacethe cylinder.
EFFECTIVITY:
Jan10/9035-10-00
PIPER AIRCRAFT
PA-42-720(AdvancedTrainer)
MAINTENANCEMANUAL
A. MaintenancePractices(continued)
4. Testingfor Leaks
Apply detector fluid (MIL-L-25567C)solution. Shakesolutionto form sudsor foam. Apply suds or
foam sparingly to the joints of a closed system. Lookfor traces of bubbles. Novisible leakage shouldbe found. Repairor replace anydefectiveparts andretest system. Withthe systempressurizedto service pressure,furthertestscan be made. Therateof any leakshould not exceed1 percent of the total supply in any 24 hour period.Wipeoff all traces of the detectorfluid at the conclusionof the examination.
An alternate methodusingnitrogenmaybe used if so desired. This methodrequiresthe following procedure:
(a)
Disconnectthe pilot's and copilot's oxygenmasklinesfromtheir outlets.
(b)
Inspectthe passengeroutlets to assure all lanyardpinsareinstalled.
(c)
Disconnectthe low pressure oxygenlinefrom the regulator attachedto the oxygencylinder.
(d)
Obtaina bottle of clean, dry nitrogenhavinga manual shutoffvalveand a sensitive pressure gauge.
(e)
Pressurizethe system to 100 +10/-10 psig, and ensurethe pressure holds. Pressuredecay is not acceptable.
(f)
If a pressuredecreaseis noted, applyleakdetectorsolution sparingly at all joints andoutlets. Lookfor tracesof bubbles. Repairanyleaks.
(g)
Wipeoff any traceof the detector solution followingthe test, andreconnect the low pressure oxygenlineto the oxygen cylinder regulator.
WARNING: DONOTACTUATEANY ELECTRICAL SWITCHESNORALLOW ANY SORTOF COMBUSTIONTO OCCURSINCECABIN AREA WILL FILLWITHEXCESS UNUSEDOXYGEN.CLEARCABINAFTERPURGINGLINES,BEFORE OPERATINGANY EQUIPMENT.
(h)
To purge any nitrogen from the system,connectall the oxygenmasks to their outletsand pull the lanyard pins. With the oxygenturnedon, wait for a minimum of 3 minutes beforeshutting it off.
(i)
Returnall masks and lanyard pins to their normalpositionsand reinstall all panels and hardware.
5. OxygenCylinderand RegulatorRemoval
The cylinder and regulator are located in the forward fuselagesection. Performthefollowingsteps to remove the cylinder andregulatorfrom the airplane:
WARNING: ENSURETHATTHE VALVE ON THE CYLINDERIS CLOSEDBEFORE DISCONNECTINGANY LINESFROMTHE REGULATOR, ANDOBSERVEALL SAFETYPRECAUTIONSRELATEDTO OXYGENSYSTEMHANDLINGAND SERVICING.
(a)
Disconnectthe control cable and pressure linesfrom the cylinder. Disconnectthe restraining cable attached to the bulkhead.
(b)
Supportthe cylinder and loosenand separate the clamps that holdthe cylinder in place.
(c)
Removethe cylinder fromthe airplane. Usecautionnot to bump the neckof the cylinder and regulator.
(d)
If the cylinder is completely empty, the regulator maybe removed.
(e)
Inspectthe cylinder and regulator in accordance with AC 43.13-1A.
EFFECTIVITY:
040-999
35-10-00Jan
PIPERAIRCRAFT
PA-42-720(AdvancedTrainer)
MAINTENANCEMANUAL
A. MaintenancePractices(continued)
6. OxygenCylinderand RegulatorInstallation
(a)
Withthe regulatorattachedto the cylinder,placethe cylinderintothe airplanethroughthe forwardbaggagecompartmentwith the regulatorfacingtowardsthe accessopening. Do not bumpthe regulatorandcylinderduringinstallation.
(b)
Positionthe cylinderso the controlonthe regulatoralignswith the controlcable.
(c)
Securethe cylinderin placeby connecting and tightening the two clamps.
(d)
Connectthe pressurelinesand controlcableto the regulator.
(e)
Rechargethe oxygencylinderif not alreadyaccomplished.Referto 12-10-00for instructions on replenishingoxygensupply.
7. ChargingValveRemoval
(a)
Openaccessdoor locatedatfuselagestation22.64.
(b)
Ensurethatthe regulatorvalveis closed.
(c)
Disconnectthe connectorfromthe chargingvalve.
(d)
Removethe three nutsand boltsholdingthe chargingvalvein placeand removethe valve throughthe accessdooron the outsideof the fuselage.
8. ChargingValveInstallation
(a)
Placethe valve intopositionthroughthe accessdooron theoutsideof the airplaneandsecure with threebolts andnuts.
(b)
Connectthe connectorto the valveusingthreadsealantandinstructionsgivenin paragraph titled OxygenSystemServicing.
(c)
Securethe accesspanel.
9. PressureGaugeRemoval
(a)
Closethe controlvalveanddepressurizethe oxygensystemas required.
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