Aircraft equipment problem.

Attributes
ACN	272370
Time
Date	199405
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mco
State Reference	FL
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Brasilia EMB-120 All Series
Operating Under FAR Part	Part 135
Navigation In Use	Other Other
Flight Phase	ground : preflight ground other : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 300 flight time total : 10000
ASRS Report	272370
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	other flight crewa
Resolutory Action	flight crew : rejected takeoff other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Upon taxi out lost oil pressure. Shut down engine. Taxied back to gate. Found oil cap off. Cap had been checked prior to taxi. Mechanic thinks .041 safety wire acted as spring to lift oil cap 'ear' and remove cap. Callback conversation with reporter revealed the following information: reporter indicated that the cap had been removed on the #1 engine for a visual oil level check in company of the mechanic because the sight gauge was too dirty to accurately determine the oil level during the preflight. The engine is made by a well known jet engine manufacturer. They had installed baffles on all their engines as a retrofit so as to prevent oil loss in cases of the oil cap coming off. Post flight inspection revealed that this engine did not have the baffles installed. Murphy's law in action? The wire that he referred to as 'lifting the ear of the cap' was a wire designed to be a 'tether,' to keep from losing the cap if it was dropped or did come off. The wire was not the pliable, light type but a heavy gauged one, about the weight of a coat hanger. The mechanic thinks that this looped up and thereby lifted the cap off it's crown. Reporter had heard of this happening a long time ago but not specifically ont the emb-120 type aircraft. Reporter has checked his other aircraft very carefully on preflight to make certain the wire is the lighter gauge wire.

Original NASA ASRS Text

Title: ACFT EQUIP PROB.

Narrative: UPON TAXI OUT LOST OIL PRESSURE. SHUT DOWN ENG. TAXIED BACK TO GATE. FOUND OIL CAP OFF. CAP HAD BEEN CHKED PRIOR TO TAXI. MECH THINKS .041 SAFETY WIRE ACTED AS SPRING TO LIFT OIL CAP 'EAR' AND REMOVE CAP. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR INDICATED THAT THE CAP HAD BEEN REMOVED ON THE #1 ENG FOR A VISUAL OIL LEVEL CHK IN COMPANY OF THE MECH BECAUSE THE SIGHT GAUGE WAS TOO DIRTY TO ACCURATELY DETERMINE THE OIL LEVEL DURING THE PREFLT. THE ENG IS MADE BY A WELL KNOWN JET ENG MANUFACTURER. THEY HAD INSTALLED BAFFLES ON ALL THEIR ENGS AS A RETROFIT SO AS TO PREVENT OIL LOSS IN CASES OF THE OIL CAP COMING OFF. POST FLT INSPECTION REVEALED THAT THIS ENG DID NOT HAVE THE BAFFLES INSTALLED. MURPHY'S LAW IN ACTION? THE WIRE THAT HE REFERRED TO AS 'LIFTING THE EAR OF THE CAP' WAS A WIRE DESIGNED TO BE A 'TETHER,' TO KEEP FROM LOSING THE CAP IF IT WAS DROPPED OR DID COME OFF. THE WIRE WAS NOT THE PLIABLE, LIGHT TYPE BUT A HVY GAUGED ONE, ABOUT THE WT OF A COAT HANGER. THE MECH THINKS THAT THIS LOOPED UP AND THEREBY LIFTED THE CAP OFF IT'S CROWN. RPTR HAD HEARD OF THIS HAPPENING A LONG TIME AGO BUT NOT SPECIFICALLY ONT THE EMB-120 TYPE ACFT. RPTR HAS CHKED HIS OTHER ACFT VERY CAREFULLY ON PREFLT TO MAKE CERTAIN THE WIRE IS THE LIGHTER GAUGE WIRE.

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.