Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Communication Breakdown
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Fuel Issue
Air Traffic Control Provided Assistance; Flight Crew Overcame Equipment Problem; General Maintenance Action
Aircraft; Company Policy; Human Factors; MEL; Procedure
I was the operating Captain on an MD-82 aircraft; flight ZZZ-ZZZ1. There was rain in the ZZZ1 area and we had ZZZ2 and ZZZ3 as alternates. The aircraft had three MEL items for problems with the right main fuel tank indications. The Cockpit Indicator would blank out and was considered inoperative and deferred; the Wing Indicator was inoperative; and therefore the Main [Fuel] Totalizer was inoperative. First Officer and I had flown this aircraft two days prior with the same MEL items. We determined the Cockpit [Fuel] Indicator was accurate and I made a logbook entry to Maintenance at that time stating that the right main indicator was accurate and correct. We got the MD-82 aircraft in ZZZ1 and flew it to ZZZ. We had all the proper sign offs and all the Fuel Quantity Indicators in the cockpit matched the numbers given [to] us by the Mechanic. En route to ZZZ the indicators once again appeared to us to be accurate and correct. We were scheduled for a 40-minute turn in ZZZ; but it stretched to 46-minutes due to the Fuel Verification procedures. At the gate in ZZZ; our [Fuel] Indicators read 9;050 LBS on the left and 4;150 LBS on the right [wing] with 3;600 LBS in the center; [equaling] 16;800 LBS; our release was 21;600 LBS. The Contract Mechanic made several trips to the cockpit to transfer fuel and to verify the correct fuel was onboard. He made several comments that the right tank was full (9;250 LBS) and the wing indicator and the main indicator in the cockpit was 'screwed-up.' He made a logbook entry that stated our fuel was 9;050 LBS left main; 9;250 LBS right main and 3;600 LBS center; for a total of 21;900 LBS. He confirmed the readings and the total fuel on board to us several times. We discussed the difference between the drip-stick reading on the right tank and the indicator reading and he assured us the tank was full and the indicators that were deferred were wrong. I had told Maintenance two days prior that the [right fuel] indicator appeared correct. They had not cleared the entry and continued with the MEL for the [Fuel] System which indicated to me that the indicator problem was intermittent in nature and had now shown up to us. Looking back at the history it appeared that the indicator was intermittent. We departed the gate with the right main tank indicating 9;050 LBS; the left indicating 4;150 LBS and the center at 3;600 LBS. We had a logbook sign off by a Certified Mechanic stating that the right main was in fact full and contained 9;250 LBS. Due [to the] intermittent nature of the indication problem; the multiple assurances by the Mechanic that the right main tank was full; and the logbook sign off stating it was full; we felt the right indicator was now incorrect and trusted the Maintenance procedures to tell the correct amount of fuel we had on board. First Officer was flying the leg to ZZZ1. Upon rotation it was very evident that we had either a flight control problem or a very large fuel imbalance. First Officer had to use nearly full right aileron to maintain wings level. We cleaned up the aircraft and slowly accelerated. We complied with the usual changes to our route of flight that we get from Departure (This added greatly to our workload at a critical time. These changes are well known and the company doesn't try to file us a different way or do anything to make it easier for us on departure because we always make it work. This time we once again made it work. You are welcome.) After some intense discussion with the First Officer; we agreed that the flight control issue was indicative of a fuel imbalance. Our indicators at the time showed 9;050 LBS in the left and 4;150 LBS in the right; we were burning center tank fuel. First Officer stated that it flew like the fuel indicators were correct and maybe the Mechanic had made a mistake on his calculations. I agreed and we immediately began to crossfeed fuel from the left tank to both engines by shutting off the boost pumps on the right main tanks and the center tanks. As the fuel quantity in the left main tank decreased; less and less aileron was required to maintain wings level. We knew we had a fuel imbalance. When the fuel quantities in both wing tanks were 4;100 LBS; the plane was perfectly in trim and flew normal. Our math and the airplane convinced us we had been shorted 5;000 LBS in the right tank and that the fuel indicators had been correct on the ramp and were correct now. I coordinated with ATC and got a more direct route to ZZZ1. I contacted Dispatch and got updated fuel burn for the new routing. We were to land with 6;200 LBS and had ZZZ3 for a good alternate. No one had been missing the approach at ZZZ1 as it was just light rain and no convective activity. We elected to continue on to ZZZ1. The approach and landing was normal and uneventful. We shut down at the gate with 5;500 LBS. Our Quantity indicators showed 2;750 LBS in the right and left main tanks. Either the dripsticks on the right wing are wrong; or the Mechanic made a huge error in determining how much fuel we had. Due to the Maintenance procedures in place; my Company dispatched me with an aircraft that had a 5;000 LBS lateral fuel imbalance. Instead of fixing the indicators or troubleshooting a bit more when I told them two days prior that the indicator was correct; they continued with the MEL and relied on a Contract Mechanic to verify and certify the fuel load. He; as an agent of our air carrier; sent us out with an aircraft that was 3;500 LBS over the Lateral Fuel Imbalance limitation. It could have been very bad. Thanks to the First Officer it was not. There are a few more things that this event highlighted for me:1)-I had a terrible time contacting Dispatch from over ZZZ4. The [flight] phone was slow to connect and broke up on his end. I got a patch through ZZZ5 and it was poor. Once we connected I got some good advice from Dispatch such as weather; routing options; and suitable land short options. He did ask if we had had the fuel verified in ZZZ; which was rude and a waste of time! I have had several instances of poor contact with Dispatch. The Frequency Chart seems totally out of date and useless. 2)-I asked Dispatch to have Maintenance meet us at the gate to talk to us. I wanted them to determine how much fuel was in the right main at shutdown. We called Maintenance after gate arrival and all the passengers had deplaned and were told there was a Mechanic assigned and he was on the way. The Mechanic showed up and told me he was going to dip the tanks and would sign off the Fuel Load. I asked him how much fuel was in the right main before he started and he said he had no idea as he just began transferring fuel. There was still a possibility that we had a flight control problem. If the right main tank had 2;750 LBS and the indicator said [that]; then we would know for sure that the Mechanic in ZZZ was wrong or that the dripsticks were wrong. The ZZZ1 Mechanic just jumped in [and] destroyed the evidence that the indicator was correct. They do not check with us before they begin work. The reporting codes we send are sometimes vague and a face to face explanation could save some time and duplication in effort. Here it would have preserved the proof of a fuel imbalance and eliminated the flight controls from discussion. [It was] very difficult to contact Dispatch from aircraft. Difficult to hear; [radio] frequencies don't work. Delay in establishing contact.
Reporter stated the MD-82's he flies have standard gauges and that over the years; he has found the gauges to be extremely accurate. Either they are working or crapped out. This was only the third time in twelve years that he can remember dealing with an MEL for the fuel gauges. Fuel gauges at the wing fueling bay are repeaters of the cockpit gauges. They do a Fuel Tank Quantity Test on the first flight of the day. Mechanics perform the fuel drip readings; flight crewmembers are no longer present during the drip check.Reporter stated his air carrier only fuels and 'drips' at the gate; because the slope and elevation on the ramp at their gates have already been surveyed. He had the aircraft for four legs and the fuel gauges were accurate on three of those legs. All three cockpit fuel gauges; including the totalizer; were within 100 LBS of indication. Since their incident of having a 5;000 LBS lateral fuel imbalance; his air carrier has revised their fuel dripstick maintenance procedures and added training.
Captain reports a 5;000 LBS wing lateral fuel imbalance on their MD-82 was noticed upon rotation; requiring almost full right aileron to correct. The right main tank fuel gauge and Totalizer had been deferred and the fuel tanks dripped for quantity. Captain noted the MD-82 had a maximum allowed lateral fuel imbalance of 1;500 LBS.