Atx small aircraft took off with the oil cap off.

Attributes
ACN	146387
Time
Date	199005
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sac
State Reference	CA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air taxi
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	climbout : takeoff ground : preflight
Flight Plan	VFR
Person 1
Affiliation	company : air taxi
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : atp pilot : cfi
Experience	flight time last 90 days : 70 flight time total : 2900 flight time type : 30
ASRS Report	146387
Person 2
Affiliation	company : air taxi
Function	other personnel other
Qualification	other other : other
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Airport
Air Traffic Incident	Pilot Deviation

Narrative:

I was called to take a 'pop-up charter' and had approximately 1 hour to prepare for the flight. This included going home to change into uniform. I was told that someone in maintenance would be directed to check the fuel and oil. I got to the airplane and did my own preflight checking everything on the checklist. I forgot to check the security of oil filler cap. This is not on the checklist. After takeoff during climb out I noticed oil coming out of oil filler cap door. I told approach control I wanted to return to the airport due to oil leaking. They told me I could land on runway 02. I did, after switching to tower and taxied to hangar. I secured the oil cap after I found it off the tube and inspected the oil quantity. It was ok. I wiped off oil and took off to continue my flight. The flight was completed with no further incident.

Original NASA ASRS Text

Title: ATX SMA TOOK OFF WITH THE OIL CAP OFF.

Narrative: I WAS CALLED TO TAKE A 'POP-UP CHARTER' AND HAD APPROX 1 HR TO PREPARE FOR THE FLT. THIS INCLUDED GOING HOME TO CHANGE INTO UNIFORM. I WAS TOLD THAT SOMEONE IN MAINT WOULD BE DIRECTED TO CHK THE FUEL AND OIL. I GOT TO THE AIRPLANE AND DID MY OWN PREFLT CHKING EVERYTHING ON THE CHKLIST. I FORGOT TO CHK THE SECURITY OF OIL FILLER CAP. THIS IS NOT ON THE CHKLIST. AFTER TKOF DURING CLB OUT I NOTICED OIL COMING OUT OF OIL FILLER CAP DOOR. I TOLD APCH CTL I WANTED TO RETURN TO THE ARPT DUE TO OIL LEAKING. THEY TOLD ME I COULD LAND ON RWY 02. I DID, AFTER SWITCHING TO TWR AND TAXIED TO HANGAR. I SECURED THE OIL CAP AFTER I FOUND IT OFF THE TUBE AND INSPECTED THE OIL QUANTITY. IT WAS OK. I WIPED OFF OIL AND TOOK OFF TO CONTINUE MY FLT. THE FLT WAS COMPLETED WITH NO FURTHER INCIDENT.

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.