Narrative:

Myself and another IFR pilot were flying on a long cross country trip and had to divert and overnight due to WX. We decided to spend some time reviewing the aircraft logs, manuals, 337's, etc. (Flying is a technical hobby for us so we spend a lot more time than any other pilots I know just talking about aircraft documents, system and the like.) while looking through some recent maintenance records, we found an invoice for a fuel bladder replacement showing a standard range tank. The flight manuals, the equipment list, and all documents we could find for that plane listed long range tanks. We had always flight planned for long range tanks based on those documents. We spoke to the club maintenance officer who said he believed they were long range tanks. The mechanic stated that based on the serial number and the tank that came out of the plane, they were standard tanks. The plane did not have placards listing tank capacity. A check on the serial number with cessna verified it had been built with standard tanks. Mr X and I are probably the only pilots in the club who regularly read the entire logs for the plane and it was just a coincidence that the invoice showing a short range tank had been left in the plane. For at least 15 yrs, the plane was flown under the belief it had long range tanks. I don't know how we could find this sort of problem. The plane was repainted a few yrs ago and had it been placarded at that time, as it should have been, it would probably have been incorrect since all the documents existing at that time showed long range tanks. The problem appears to be that somewhere down the line, someone made the assumption the plane had long range tanks and wrote it down without looking at a written document confirming the fact. Once it was written it was spread by other people through all the documents associated with the plane. There is nothing in the pilots handbook as to how to verify the information other than relying on placards and documents. One possible solution to this is from the automatic industry. They encode the serial number to list all of the major options the car was shipped with and then provide a decoding table in the operators and maintenance manuals. I don't know what to do about flying rental aircraft where you can only assume the paperwork is correct. I will probably have any plane I intend to fly toward the limit of its endurance defueled and then verify actual capacity. I have found this same problem with incorrect data being passed down before. During initial fitting of avionics into a plane I owned, they made an error and subtracted 2 radios rather than added them into the weight and balance. The total difference was 60 pounds (in a 310 it had no major impact). The error was made in 1965 and carried through every weight and balance up to 1995 when the plane was reweighed and I questioned why it didn't match the old weight and balance. Recalculating every weight and balance found the discrepancy. The entire fuel tank issue was a very personal finding for me since the longest flight the plane had ever been on was when mr X and I flew it from south dakota to billings, mt, in MVFR/IMC at night. We planned 5.25 flight time plus 2.25 reserve based on long range tanks. Flight time was 5.5 hours. We took on 66 gallons of fuel. Usable fuel is 65 gallons on standard tanks.

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Original NASA ASRS Text

Title: PLT OF A C182 FINDS THE DOCUMENTATION REGARDING LONG RANGE FUEL TANKS ON THE ACFT IS INCORRECT AND STANDARD TANKS WERE INSTALLED.

Narrative: MYSELF AND ANOTHER IFR PLT WERE FLYING ON A LONG XCOUNTRY TRIP AND HAD TO DIVERT AND OVERNIGHT DUE TO WX. WE DECIDED TO SPEND SOME TIME REVIEWING THE ACFT LOGS, MANUALS, 337'S, ETC. (FLYING IS A TECHNICAL HOBBY FOR US SO WE SPEND A LOT MORE TIME THAN ANY OTHER PLTS I KNOW JUST TALKING ABOUT ACFT DOCUMENTS, SYS AND THE LIKE.) WHILE LOOKING THROUGH SOME RECENT MAINT RECORDS, WE FOUND AN INVOICE FOR A FUEL BLADDER REPLACEMENT SHOWING A STANDARD RANGE TANK. THE FLT MANUALS, THE EQUIP LIST, AND ALL DOCUMENTS WE COULD FIND FOR THAT PLANE LISTED LONG RANGE TANKS. WE HAD ALWAYS FLT PLANNED FOR LONG RANGE TANKS BASED ON THOSE DOCUMENTS. WE SPOKE TO THE CLUB MAINT OFFICER WHO SAID HE BELIEVED THEY WERE LONG RANGE TANKS. THE MECH STATED THAT BASED ON THE SERIAL NUMBER AND THE TANK THAT CAME OUT OF THE PLANE, THEY WERE STANDARD TANKS. THE PLANE DID NOT HAVE PLACARDS LISTING TANK CAPACITY. A CHK ON THE SERIAL NUMBER WITH CESSNA VERIFIED IT HAD BEEN BUILT WITH STANDARD TANKS. MR X AND I ARE PROBABLY THE ONLY PLTS IN THE CLUB WHO REGULARLY READ THE ENTIRE LOGS FOR THE PLANE AND IT WAS JUST A COINCIDENCE THAT THE INVOICE SHOWING A SHORT RANGE TANK HAD BEEN LEFT IN THE PLANE. FOR AT LEAST 15 YRS, THE PLANE WAS FLOWN UNDER THE BELIEF IT HAD LONG RANGE TANKS. I DON'T KNOW HOW WE COULD FIND THIS SORT OF PROB. THE PLANE WAS REPAINTED A FEW YRS AGO AND HAD IT BEEN PLACARDED AT THAT TIME, AS IT SHOULD HAVE BEEN, IT WOULD PROBABLY HAVE BEEN INCORRECT SINCE ALL THE DOCUMENTS EXISTING AT THAT TIME SHOWED LONG RANGE TANKS. THE PROB APPEARS TO BE THAT SOMEWHERE DOWN THE LINE, SOMEONE MADE THE ASSUMPTION THE PLANE HAD LONG RANGE TANKS AND WROTE IT DOWN WITHOUT LOOKING AT A WRITTEN DOCUMENT CONFIRMING THE FACT. ONCE IT WAS WRITTEN IT WAS SPREAD BY OTHER PEOPLE THROUGH ALL THE DOCUMENTS ASSOCIATED WITH THE PLANE. THERE IS NOTHING IN THE PLTS HANDBOOK AS TO HOW TO VERIFY THE INFO OTHER THAN RELYING ON PLACARDS AND DOCUMENTS. ONE POSSIBLE SOLUTION TO THIS IS FROM THE AUTO INDUSTRY. THEY ENCODE THE SERIAL NUMBER TO LIST ALL OF THE MAJOR OPTIONS THE CAR WAS SHIPPED WITH AND THEN PROVIDE A DECODING TABLE IN THE OPERATORS AND MAINT MANUALS. I DON'T KNOW WHAT TO DO ABOUT FLYING RENTAL ACFT WHERE YOU CAN ONLY ASSUME THE PAPERWORK IS CORRECT. I WILL PROBABLY HAVE ANY PLANE I INTEND TO FLY TOWARD THE LIMIT OF ITS ENDURANCE DEFUELED AND THEN VERIFY ACTUAL CAPACITY. I HAVE FOUND THIS SAME PROB WITH INCORRECT DATA BEING PASSED DOWN BEFORE. DURING INITIAL FITTING OF AVIONICS INTO A PLANE I OWNED, THEY MADE AN ERROR AND SUBTRACTED 2 RADIOS RATHER THAN ADDED THEM INTO THE WT AND BAL. THE TOTAL DIFFERENCE WAS 60 LBS (IN A 310 IT HAD NO MAJOR IMPACT). THE ERROR WAS MADE IN 1965 AND CARRIED THROUGH EVERY WT AND BAL UP TO 1995 WHEN THE PLANE WAS REWEIGHED AND I QUESTIONED WHY IT DIDN'T MATCH THE OLD WT AND BAL. RECALCULATING EVERY WT AND BAL FOUND THE DISCREPANCY. THE ENTIRE FUEL TANK ISSUE WAS A VERY PERSONAL FINDING FOR ME SINCE THE LONGEST FLT THE PLANE HAD EVER BEEN ON WAS WHEN MR X AND I FLEW IT FROM SOUTH DAKOTA TO BILLINGS, MT, IN MVFR/IMC AT NIGHT. WE PLANNED 5.25 FLT TIME PLUS 2.25 RESERVE BASED ON LONG RANGE TANKS. FLT TIME WAS 5.5 HRS. WE TOOK ON 66 GALLONS OF FUEL. USABLE FUEL IS 65 GALLONS ON STANDARD TANKS.

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.