Narrative:

We departed with main tanks full and aux tanks with 60 gallons. The flight was planned as 2 hours and 30 minutes but ended up 2 hours and 45 minutes due to diversions for weather. I was pilot flying during dual instruction to comply with insurance requirements for PIC authorization. Instructor pilot was in co-pilot seat. On the way to the initial fix for the GPS approach I noticed the left fuel indicator was moving down into the yellow arc. I called that to the other pilot's attention and the indicator was noticeably moving. I looked and saw the cap was on the wing and we didn't appear to be losing fuel. We had entered the fuel on board in the FMS upon departure and it showed we should have 1 hour and 45 min of fuel on board. We asked ATC for shortcuts on the approach and they advised they were not able. The right fuel gauge also appeared to be lower that normal and moving toward empty. The co-pilot checked his wing and also stated we did not appear to be losing fuel. I then advised the I.P. To declare an emergency and that I was going to the final approach fix for the field. I pulled and reset the circuit breaker for that gauge but it did not fix the problem. The left gauge went to zero; but the engine continued to run. The right gauge also began dropping. The co-pilot checked the FMS again and it showed we should have over 1;100 pounds of fuel on landing. I then turned inside the final approach fix and joined final. The ILS glide slope was out of service and the GPS was not sequenced to join inside the final to display vertical path. The altitude on the ILS approach was 1;700 ft and the ceiling was reported as 1;400 ft. I turned toward the field and got a low altitude alert from ATC. This was due to my turning inside the fix to go directly to the field and approximating the altitude. I continued and landed uneventfully. Upon landing we had the main tanks filled and found the FMS was correct and we had approximately 160 gallons on board. After filling the aircraft one gauge indicated 600 pounds and the other indicated 800 pounds instead of the over 1;200 pounds that should have shown on each side. I had previously been an instructor on an aircraft in a similar incident where the fuel gauges moved rapidly toward zero; (in IMC). I declared an emergency and got an ASR to the nearest field and upon landing we discovered the fuel line was ruptured and was pouring raw fuel into the engine compartment but enough was still getting to the engine to make it run. We had poured over 2 hours of fuel through the engine compartment in approximately 15 minutes of flying. With my previous experience I felt compelled to declare an emergency and 'short cut' the approach with the possibility of an actual fuel leak. I was busy flying and dealing with the second gauge issue and the co-pilot (instructor pilot) was busy with ATC. As the second gauge started going toward zero I changed from intercepting outside the final to going directly to the field. I should have made him reset the approach for some vertical guidance inside the final. I thought the three hundred feet between the initial altitude and the reported ceiling was the only thing until VFR. I did have some ground contact and knew my location and surrounding obstructions and felt safe in the altitude deviation. I am a helicopter pilot in the local area and do most of those operations at 500 ft and below so knowing my location and obstructions made me confident in the safety of the approach. The ceiling was lower than expected but I did break out and continued visually to the field.

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Original NASA ASRS Text

Title: King Air pilot reports low fuel indication on the fuel gauges during approach although the flight departed with sufficient fuel. An emergency is declared and a short cut is made on the approach along with an early descent; resulting in a low altitude alert from ATC. A normal landing ensues and post flight reveals faulty fuel gauges.

Narrative: We departed with main tanks full and aux tanks with 60 gallons. The flight was planned as 2 hours and 30 minutes but ended up 2 hours and 45 minutes due to diversions for weather. I was pilot flying during dual instruction to comply with insurance requirements for PIC authorization. Instructor pilot was in co-pilot seat. On the way to the initial fix for the GPS approach I noticed the left fuel indicator was moving down into the yellow arc. I called that to the other pilot's attention and the indicator was noticeably moving. I looked and saw the cap was on the wing and we didn't appear to be losing fuel. We had entered the fuel on board in the FMS upon departure and it showed we should have 1 hour and 45 min of fuel on board. We asked ATC for shortcuts on the approach and they advised they were not able. The right fuel gauge also appeared to be lower that normal and moving toward empty. The co-pilot checked his wing and also stated we did not appear to be losing fuel. I then advised the I.P. to declare an emergency and that I was going to the final approach fix for the field. I pulled and reset the circuit breaker for that gauge but it did not fix the problem. The left gauge went to zero; but the engine continued to run. The right gauge also began dropping. The co-pilot checked the FMS again and it showed we should have over 1;100 LBS of fuel on landing. I then turned inside the final approach fix and joined final. The ILS glide slope was out of service and the GPS was not sequenced to join inside the final to display vertical path. The altitude on the ILS approach was 1;700 FT and the ceiling was reported as 1;400 FT. I turned toward the field and got a low altitude alert from ATC. This was due to my turning inside the fix to go directly to the field and approximating the altitude. I continued and landed uneventfully. Upon landing we had the main tanks filled and found the FMS was correct and we had approximately 160 gallons on board. After filling the aircraft one gauge indicated 600 pounds and the other indicated 800 LBS instead of the over 1;200 LBS that should have shown on each side. I had previously been an instructor on an aircraft in a similar incident where the fuel gauges moved rapidly toward zero; (In IMC). I declared an emergency and got an ASR to the nearest field and upon landing we discovered the fuel line was ruptured and was pouring raw fuel into the engine compartment but enough was still getting to the engine to make it run. We had poured over 2 hours of fuel through the engine compartment in approximately 15 minutes of flying. With my previous experience I felt compelled to declare an emergency and 'short cut' the approach with the possibility of an actual fuel leak. I was busy flying and dealing with the second gauge issue and the co-pilot (instructor pilot) was busy with ATC. As the second gauge started going toward zero I changed from intercepting outside the final to going directly to the field. I should have made him reset the approach for some vertical guidance inside the final. I thought the three hundred feet between the initial altitude and the reported ceiling was the only thing until VFR. I did have some ground contact and knew my location and surrounding obstructions and felt safe in the altitude deviation. I am a helicopter pilot in the local area and do most of those operations at 500 FT and below so knowing my location and obstructions made me confident in the safety of the approach. The ceiling was lower than expected but I did break out and continued visually to the field.

Data retrieved from NASA's ASRS site as of July 2013 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.