Gas cap noticed missing after 50 mins of flight on a BE76.

Attributes
ACN	463040
Time
Date	200002
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	navaid : ccr.vor
State Reference	CA
Altitude	msl single value : 6000
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Operator	general aviation : instructional
Make Model Name	Duchess 76
Operating Under FAR Part	Part 91
Navigation In Use	other vortac
Flight Phase	cruise : level
Flight Plan	None
Person 1
Affiliation	other
Function	instruction : trainee
Qualification	pilot : multi engine pilot : cfi pilot : commercial pilot : instrument
Experience	flight time last 90 days : 150 flight time total : 1500 flight time type : 30
ASRS Report	463040
Person 2
Affiliation	government : faa
Function	instruction : instructor
Qualification	pilot : multi engine pilot : instrument pilot : commercial pilot : cfi
Events
Anomaly	aircraft equipment problem : less severe non adherence : published procedure non adherence : far other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : landed as precaution
Consequence	faa : reviewed incident with flight crew other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Aircraft

Narrative:

After a very careful preflight, during a multi-engine instructor check ride, the right gas cap was observed to be missing after approximately 50 mins of flight. Landing was uneventful. Left and right tanks had 30 usable gals of fuel on landing (1 hour flight with 40 usable gals in each tank on takeoff).

Original NASA ASRS Text

Title: GAS CAP NOTICED MISSING AFTER 50 MINS OF FLT ON A BE76.

Narrative: AFTER A VERY CAREFUL PREFLT, DURING A MULTI-ENG INSTRUCTOR CHK RIDE, THE R GAS CAP WAS OBSERVED TO BE MISSING AFTER APPROX 50 MINS OF FLT. LNDG WAS UNEVENTFUL. L AND R TANKS HAD 30 USABLE GALS OF FUEL ON LNDG (1 HR FLT WITH 40 USABLE GALS IN EACH TANK ON TKOF).

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.