Date: 201507
Local time of day: 1801-2400
Location: ZAU.ARTCC, IL
Flight conditions: VMC
Light: Night
Aircraft: B757-200
Operator: Air Carrier
Operating under: Part 121
Mission: Cargo / Freight / Delivery
Flight phase: Initial Approach
Airspace: Class A ZAU
ATC / advisory: Center ZAU; TRACON IND
Reporter organization: Air Carrier
Reporter function: First Officer
Second reporter function: Captain
Anomaly: Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Fuel Issue
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Took Evasive Action
Contributing factors: Company Policy; Weather; Procedure
Primary problem: Ambiguous

Narrative: West bound approximately around BNA received ACARS from Dispatch to divert to SBN. Enroute to SBN passing IND second ACARS message advising to cancel the divert due to another aircraft with more uplift ability would be recovering the freight and we would now be diverting back to ZZZ. Fuel on board was now insufficient for us to return to ZZZ. Dispatch advised to continue to SBN. Shortly after received another ACARS to cancel divert to SBN and now divert to IND for gas and go. Believe IND was closer at the time also. Numbers from Dispatch for IND had us slightly above Emergency fuel at IND. Minimum fuel was declared at this time with ATC. Believe the fuel was projected to land with 5.2 at IND. ATC was trying to accommodate us without delay but while on very short final to 5L the fuel quantity dropped just below 5.0. Landing was continued and taxied to the gate uneventful. Blocked into the gate with 4.4 onboard and contribute this quantity due to the longer taxi in from 5L.The divert to a distant airport without a lot of extra fuel. The diversions enroute due to weather. The multiple revisions as to where we were diverting to. The initial heading from Chicago Center causing an initial delay in heading back towards IND. If designated as [an airborne back up] flight carry more fuel to divert airport for unplanned events; ie enroute WX; change of divert airport; traffic etc...


Second narrative: Originally flight planned to ZZZ. Passing BNA; Dispatch diverted Flt to SBN. Received WX/NOTAMS/fuel burn and proceeded to SBN. Off course deviation twice en route around WX to SBN. ACARS exchange querying position and fuel just prior to THH VOR. I believe at this point Dispatch was thinking about bring us back to ZZZ. Started descent just prior to abeam IND and received second ACARS divert message to proceed to IND. WX/NOTAMS received and fuel burn indicated landing at IND above 5000 lbs fuel. Reprogrammed FMS for RW 5L and JAKKS 1 arrival fuel predict was 5.2 at IND landing. This was lower than I had expected as we had just flown abeam IND only what seemed moments prior. Initial heading 270 from Center prompted me to declare min fuel. We were on the westerly heading for a few minutes. Indy Center and Approach did a good job vectoring the Flt to 5L. After landing roll out we exited the runway at Romeo. Fuel state read approximately 4.9. I am not sure of our exact fuel at touch down as a safe landing was the top priority at that point. No emergency had been declared as I felt we would land above 5000 lbs fuel. The task loading from the start of the descent towards SBN until landing at IND became very high. The First Officer did an excellent job flying and offering input.There has always been healthy pressure to protect service and our product. Within the last year or so it seems we are 'squeezing the turnip' a little harder than usual. Service protection pressure; two diverts on the same leg in opposite directions; en route weather; delay vectors; fuel saving are some of the factors which caused this flight to land right at or slightly below emergency fuel. Neither myself nor Dispatch has any control over weather and little control over ATC. What we do have control of is the fuel uplift at the departure airport. Myself and the dispatcher also have the ability to say 'NO' I cannot divert because that will place the flight too close to FOM minimum requirements and or erode the margin of safety to an unacceptable level. Dispatch [airborne back up] flights with more fuel for contingencies or do not divert flights that may have min or emergency fuel issues.


Synopsis: B757 flight crew and the Dispatcher involved describe an unplanned diversion to SBN which is then changed again to IND. Due to weather and ATC handling the crew reports landing at IND with less than 5000 pounds of fuel.