Divert land with propeller oil problem.

Attributes
ACN	278667
Time
Date	199407
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : mrb airport : bwi
State Reference	WV
Altitude	msl bound lower : 13000 msl bound upper : 13000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	SF 340A
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other other
Route In Use	enroute airway : zny
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : commercial pilot : atp
Experience	flight time last 90 days : 250 flight time total : 8100 flight time type : 2000
ASRS Report	278667
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : declared emergency none taken : unable other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Right-H-AC generator was MEL'ed jul/xx/94 CAT B due aug/xx/94. Jul/xx/94 on a flight from yyz to iad, we got an oil pressure low warning for right engine/propeller. Checked gauges, found right propeller oil pressure low but still within operating limits (approximately 28 psig) monitored pressure and when pressure dropped to 25 psig, we performed propeller low oil pressure checklist, which calls for power lever to flight idle and condition lever to min position and monitor pressures, temperatures and rpms after about 10 mins pressure was continuing to fall and, when it reached 5 psig, we performed a precautionary engine shutdown per the checklist. We followed all checklists and landed without further incident in bwi. Emergency was declared and crash equipment was standing by. We followed all known company and good operating procedures. No injuries or aircraft damage occurred. Note: the MEL item 24-21-1 does not require maintenance action if the AC generator fails. If a mechanic had inspected this generator prior to the deferral I don't think this incident would have occurred because I believe the mechanical defect would have been found. Note 2: after landing we opened engine cowl and found the generator case had broken and oil had leaked out from where the shaft fits into the gear box.

Original NASA ASRS Text

Title: DIVERT LAND WITH PROP OIL PROB.

Narrative: R-H-AC GENERATOR WAS MEL'ED JUL/XX/94 CAT B DUE AUG/XX/94. JUL/XX/94 ON A FLT FROM YYZ TO IAD, WE GOT AN OIL PRESSURE LOW WARNING FOR R ENG/PROP. CHKED GAUGES, FOUND R PROP OIL PRESSURE LOW BUT STILL WITHIN OPERATING LIMITS (APPROX 28 PSIG) MONITORED PRESSURE AND WHEN PRESSURE DROPPED TO 25 PSIG, WE PERFORMED PROP LOW OIL PRESSURE CHKLIST, WHICH CALLS FOR PWR LEVER TO FLT IDLE AND CONDITION LEVER TO MIN POS AND MONITOR PRESSURES, TEMPS AND RPMS AFTER ABOUT 10 MINS PRESSURE WAS CONTINUING TO FALL AND, WHEN IT REACHED 5 PSIG, WE PERFORMED A PRECAUTIONARY ENG SHUTDOWN PER THE CHKLIST. WE FOLLOWED ALL CHKLISTS AND LANDED WITHOUT FURTHER INCIDENT IN BWI. EMER WAS DECLARED AND CRASH EQUIP WAS STANDING BY. WE FOLLOWED ALL KNOWN COMPANY AND GOOD OPERATING PROCS. NO INJURIES OR ACFT DAMAGE OCCURRED. NOTE: THE MEL ITEM 24-21-1 DOES NOT REQUIRE MAINT ACTION IF THE AC GENERATOR FAILS. IF A MECH HAD INSPECTED THIS GENERATOR PRIOR TO THE DEFERRAL I DON'T THINK THIS INCIDENT WOULD HAVE OCCURRED BECAUSE I BELIEVE THE MECHANICAL DEFECT WOULD HAVE BEEN FOUND. NOTE 2: AFTER LNDG WE OPENED ENG COWL AND FOUND THE GENERATOR CASE HAD BROKEN AND OIL HAD LEAKED OUT FROM WHERE THE SHAFT FITS INTO THE GEAR BOX.

Data retrieved from NASA's ASRS site as of July 2007 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.