Narrative:

Departed for a civil air patrol mission sortie in south az. The first part of the flight to tus was flown by person 2 with myself (person 1) in the right seat. After eating, refueling and filing a new flight plan, we preflted the aircraft and with me flying, took off for nogales where we turned right (west) for the first leg of the mission to a point 15 mi west of lukeville, az. The route of flight involved several climbs and dscnts since it was done at low elevation. The return leg to nogales was made at a higher altitude and did not require as many altitude changes. The mixture was adjusted several times as changes in altitude were made, and except for climbs the power was pulled back to get a 1/2' drop in manifold pressure to engage the economizer jet. After reaching nogales the flight continued at low altitude again to the vicinity of naco (mexico) where it was necessary to divert northeast over bisbee, az to avoid thunderstorms. We returned to the original flight path about 3 mi east of douglas, az and continued east to the NM state line, where we again climbed and returned west. Somewhere to the west of douglas person 2 noticed that the right tank gauge was indicating very little fuel while the left was indicating about 1/2 a tank. We switched to the left tank and continued on with the flight. After we passed miller peak we noticed thunderstorms ahead and after contacting the tus FSS and finding the R2303 would be inactive for at least 1 hour, diverted north toward tus. Nearing the top of the ridge of mt wrightson, person 2 mentioned that we were indicating about 1/8 tank. Since we were now closest to tus, we continued on with the flight. Shortly after crossing the ridge and with tus in sight, the engine lost power. Person 2 contacted tus FSS told them of the power loss and that we were making a precautionary landing. After following emergency procedure and failing to regain power, we set up for an made a full flaps landing on a dirt road east of the town of continental. After the landing we again contacted the FSS and told them we were down safely with no injuries to aircraft or passenger and they asked us about assistance. A helicopter ranger was dispatched and after landing on the road in front of us ferried me to tus for a can of fuel. After refueling we took off again and landed, topped off the tanks and returned to flagstaff. At the time of the precautionary landing we had been airborne for exactly 5.0 hours. With 54 gals of fuel and a normal burn rate of about 7.5 gph our usual range is about 7 hours and at the very worst 6 hours. Calculation of our usage on this flight indicates about 10.6 gph. On the return flight to flagstaff the burn was 6.8 gph. We cannot account for the abnormally high fuel usage on this flight. The 'fact' that small aircraft has a minimum range of 6 hours undoubtedly contributed to our ignoring the danger signals mentioned earlier. Neither of us was in the least disturbed by the low fuel indication near douglas and the loss of power came as a complete surprise. When we checked the plane over after the precautionary landing we found the right tank dry and the left with about 1' remaining. The question bothering me is, why would 2 experienced search pilots, well aware of the causes of many crashes, totally ignore the signals presented by the fuel gauges. Fuel gauges often are in error but the indications still cannot be ignored yet our confidence in the range of the aircraft let the 2 of us continue blithely on. The psychology of this has me extremely disturbed.

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Original NASA ASRS Text

Title: SMA ON CAP MISSION SUFFERS FUEL EXHAUSTION AND MAKES PRECAUTIONARY LNDG.

Narrative: DEPARTED FOR A CIVIL AIR PATROL MISSION SORTIE IN S AZ. THE FIRST PART OF THE FLT TO TUS WAS FLOWN BY PERSON 2 WITH MYSELF (PERSON 1) IN THE RIGHT SEAT. AFTER EATING, REFUELING AND FILING A NEW FLT PLAN, WE PREFLTED THE ACFT AND WITH ME FLYING, TOOK OFF FOR NOGALES WHERE WE TURNED RIGHT (W) FOR THE FIRST LEG OF THE MISSION TO A POINT 15 MI W OF LUKEVILLE, AZ. THE RTE OF FLT INVOLVED SEVERAL CLBS AND DSCNTS SINCE IT WAS DONE AT LOW ELEVATION. THE RETURN LEG TO NOGALES WAS MADE AT A HIGHER ALT AND DID NOT REQUIRE AS MANY ALT CHANGES. THE MIXTURE WAS ADJUSTED SEVERAL TIMES AS CHANGES IN ALT WERE MADE, AND EXCEPT FOR CLBS THE PWR WAS PULLED BACK TO GET A 1/2' DROP IN MANIFOLD PRESSURE TO ENGAGE THE ECONOMIZER JET. AFTER REACHING NOGALES THE FLT CONTINUED AT LOW ALT AGAIN TO THE VICINITY OF NACO (MEXICO) WHERE IT WAS NECESSARY TO DIVERT NE OVER BISBEE, AZ TO AVOID TSTMS. WE RETURNED TO THE ORIGINAL FLT PATH ABOUT 3 MI E OF DOUGLAS, AZ AND CONTINUED E TO THE NM STATE LINE, WHERE WE AGAIN CLBED AND RETURNED W. SOMEWHERE TO THE W OF DOUGLAS PERSON 2 NOTICED THAT THE RIGHT TANK GAUGE WAS INDICATING VERY LITTLE FUEL WHILE THE LEFT WAS INDICATING ABOUT 1/2 A TANK. WE SWITCHED TO THE LEFT TANK AND CONTINUED ON WITH THE FLT. AFTER WE PASSED MILLER PEAK WE NOTICED TSTMS AHEAD AND AFTER CONTACTING THE TUS FSS AND FINDING THE R2303 WOULD BE INACTIVE FOR AT LEAST 1 HR, DIVERTED N TOWARD TUS. NEARING THE TOP OF THE RIDGE OF MT WRIGHTSON, PERSON 2 MENTIONED THAT WE WERE INDICATING ABOUT 1/8 TANK. SINCE WE WERE NOW CLOSEST TO TUS, WE CONTINUED ON WITH THE FLT. SHORTLY AFTER XING THE RIDGE AND WITH TUS IN SIGHT, THE ENG LOST PWR. PERSON 2 CONTACTED TUS FSS TOLD THEM OF THE PWR LOSS AND THAT WE WERE MAKING A PRECAUTIONARY LNDG. AFTER FOLLOWING EMER PROC AND FAILING TO REGAIN PWR, WE SET UP FOR AN MADE A FULL FLAPS LNDG ON A DIRT ROAD E OF THE TOWN OF CONTINENTAL. AFTER THE LNDG WE AGAIN CONTACTED THE FSS AND TOLD THEM WE WERE DOWN SAFELY WITH NO INJURIES TO ACFT OR PAX AND THEY ASKED US ABOUT ASSISTANCE. A HELI RANGER WAS DISPATCHED AND AFTER LNDG ON THE ROAD IN FRONT OF US FERRIED ME TO TUS FOR A CAN OF FUEL. AFTER REFUELING WE TOOK OFF AGAIN AND LANDED, TOPPED OFF THE TANKS AND RETURNED TO FLAGSTAFF. AT THE TIME OF THE PRECAUTIONARY LNDG WE HAD BEEN AIRBORNE FOR EXACTLY 5.0 HRS. WITH 54 GALS OF FUEL AND A NORMAL BURN RATE OF ABOUT 7.5 GPH OUR USUAL RANGE IS ABOUT 7 HRS AND AT THE VERY WORST 6 HRS. CALCULATION OF OUR USAGE ON THIS FLT INDICATES ABOUT 10.6 GPH. ON THE RETURN FLT TO FLAGSTAFF THE BURN WAS 6.8 GPH. WE CANNOT ACCOUNT FOR THE ABNORMALLY HIGH FUEL USAGE ON THIS FLT. THE 'FACT' THAT SMA HAS A MINIMUM RANGE OF 6 HRS UNDOUBTEDLY CONTRIBUTED TO OUR IGNORING THE DANGER SIGNALS MENTIONED EARLIER. NEITHER OF US WAS IN THE LEAST DISTURBED BY THE LOW FUEL INDICATION NEAR DOUGLAS AND THE LOSS OF PWR CAME AS A COMPLETE SURPRISE. WHEN WE CHKED THE PLANE OVER AFTER THE PRECAUTIONARY LNDG WE FOUND THE RIGHT TANK DRY AND THE LEFT WITH ABOUT 1' REMAINING. THE QUESTION BOTHERING ME IS, WHY WOULD 2 EXPERIENCED SEARCH PLTS, WELL AWARE OF THE CAUSES OF MANY CRASHES, TOTALLY IGNORE THE SIGNALS PRESENTED BY THE FUEL GAUGES. FUEL GAUGES OFTEN ARE IN ERROR BUT THE INDICATIONS STILL CANNOT BE IGNORED YET OUR CONFIDENCE IN THE RANGE OF THE ACFT LET THE 2 OF US CONTINUE BLITHELY ON. THE PSYCHOLOGY OF THIS HAS ME EXTREMELY DISTURBED.

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.